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| # | Company | Amount |
|---|---|---|
| 1 | ₹100 139 2 SECOND FLOOR KODAMBAKKAM HIGH ROAD NUNGAMBAKKAM CHENNAI 600 034 | ₹100 |
Tender Value
₹208.3 Cr
Closing Date
17 Dec 2021, 11:00 amClosed
Construction of 600 Nos. 2 BHK Social Housing Units in Hulhumale, Republic of Maldives Pkg-I
NBCC/CPG/SocialHousing/Maldives/Pkg-I/2021/301
NBCC/CPG/SocialHousing/Maldives/Pkg-I/2021/301
Open Tender-Domestic
Civil Works General
Unknown (Unspecified Location)
₹2.4 L
Exempted
18 Sept 2021
18 Sept 2021
17 Dec 2021
17 Dec 2021
31 Dec 2021
Technical Specifications along with indicative BOQ
6. Indicative Bill of Quantities 160 – 205
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
SPECIFICATIONS (CIVIL WORKS)
The general conditions and special conditions of the contract including the
drawings shall be read in conjunction with these technical specifications,
and matters referred to, shown or described in one are not necessarily
repeated in the other. These specifications are comprehensive but may
exceed the requirements of this project.
Notwithstanding the sub-division of the specification into various
headings, every part of it is to be deemed supplementary to every other
part and is to be read with it, so far as it may be practicable so to do, or
when the context so permits
The specifications for the works shall be in accordance with C.P.W.D.
specifications Volume I & II in force (with upto date correction slips)
unless otherwise specified in the nomenclature of individual item or in the
specifications. The entire work shall be carried out as per the latest
C.P.W.D. specifications in force with up to date correction slips up to the
last date of submission of tender.
For the items not covered under CPWD Specifications mentioned above,
the work shall be executed as per latest relevant standards/codes
published by B.I.S. (formerly ISI) inclusive of all amendments issued
thereto or revision thereof, if any, up to the last date of submission of
In case of B.I.S. (formerly I.S.I) codes/specifications are not available;
the decision of the Engineer-in-Charge based on acceptable sound
engineering practice and local usage shall be final and binding on the
The Contractor shall be responsible for furnishing all materials required for
execution of the Works. The Contractor shall submit the source and
method of execution for the Engineer-in-Charge’s review before any
execution. All materials used in the construction of permanent works
required under this Contract shall be of 1st class quality as specified
herein and comply with the latest IS Codes or equivalent. The material
shall be tested before bringing it to the site.
This specification establishes and defines the requirements of various
materials to be used in works. Whenever any reference to IS Codes is
made, the same shall be taken as the latest revision (with all
amendments issued thereto) as on the date of submission of the Tender.
Apart from the IS Codes mentioned in particular in various clauses of this
specification, all other relevant codes related to specific job under
consideration regarding quality, tests, testing and/or inspection
procedures shall be applicable. Reference to some of the codes in various
clauses of this specification does not limit or restrict the scope of
applicability of other referred or relevant codes.
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
In case of any variation/contradiction between the provision of IS Codes
and this section, the provision given in this section shall be followed,
unless the Engineer-in- Charge agrees/consents to follow IS codes or
other proposal of the Contractor as provided in the Contract.
All materials shall be of standard quality and shall be procured from
renowned sources/manufacturers approved by the Engineer-in-Charge. It
shall be the responsibility of the Contractor, to get all
materials/manufacturers approved by the Engineer-in-Charge prior to
procurement and placement of order.
Wherever MAKE is not mentioned, Contractor shall take prior approval of
MAKE complying with the tender specifications however mentioning the
MAKE considered in the Bid submission shall prevail if specified earlier.
Whenever called for by the Engineer-in-Charge, all tests of the materials
as specified by the relevant IS Codes shall be carried out by the
Contractor in an approved laboratory and test reports duly authenticated
by the laboratory, shall be submitted to the Engineer-in-Charge for his
approval. If so desired by the Engineer-in-Charge, tests shall be
conducted in the presence of the Engineer-in-Charge or his authorized
Quality and acceptability of materials not covered under this section shall
be governed by the relevant IS Codes. In case IS code is not available for
the particular material, other codes e.g. B.S. or DIN or API/ASTM etc.
shall be considered. The decision of Engineer-in-Charge in this regard
shall be final and binding on the Contractor.
Whenever asked for, the Contractor shall submit representative samples
of materials to the Engineer-in-Charge for his inspection and approval.
Approval of any samples does not necessarily exempt the Contractor from
submitting necessary test reports for the approved material, as per the
specification/relevant IS Codes.
The Contractor shall submit manufacturer’s test reports on quality and
suitability of any material procured from them and their recommendation
on storage, application, workmanship etc. for the intended use.
Submission of manufacturer’s test reports does not restrict the Engineer-
in-Charge from asking fresh test results from an approved laboratory of
the actual material supplied from an approved manufacturer/source at
any stage of execution of work.
All costs relating to or arising out of the tests and submission of test
reports and or samples to the Engineer-in-Charge for his approval till the
date of issuance of Performance Certificate shall be borne by the
Materials for approval shall be separately stored and marked, as directed
by the Engineer-in-Charge and shall not be used in the Works till these
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
All rejected materials shall be immediately removed from the site by the
Contractor at his own cost.
1.2 General Standards
The facilities shall be completed to high standards of construction and
specification. The facilities shall be technically and functionally suitable to
meet the Engineer-in-Charge's objectives:-
i) The material procured or to be used should be to the satisfaction of
the Engineer-in-Charge before being used for the works intended to.
ii) All sanitary/water supply fixture and fittings shall be of approved
make confirming to IS specifications and with ISI Marks.
iii) Lighting should confirm to NBC for Lighting. All electrical system,
fixtures, fittings etc. should confirm to the requirement of Local
Authority, CPWD specifications, latest IS code etc.
iv) Finishing in the room of all buildings should be complete in all
respects including necessary services works and installations.
v) All moving plant, machinery and apparatus be statically and
dynamically balanced at manufactures work and certificate issued.
1.3 Statutory, Industry and Local Standards
The following standards shall apply unless otherwise stated:-
a) The standards set out in National Building Code of India 2016 & BIS
b) The relevant Development Control Rules/Planning Act/Development
Act/ Municipal Act/any other applicable statutes and local by-laws.
c) The National Electrical Code, 1985
d) The Indian Electricity Act 2003
e) Requirements of the local Water Supply Company, Electricity
Supply Company/ Department
f) Requirements of the Pollution Control Board, Environment
clearances, NOC from Fire department, Forest Department for tree
cutting, Lift license, Explosive department, Aviation authorities if
g) Any other statutory requirement for execution of work and to
occupy the buildings and run the services in all respects
1.4 Unacceptable Materials and Processes
The materials and processes given below must not be used in the New
Facilities or in connection with the New Facilities.
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
a) High alumina cement in structural elements.
b) Calcium chloride as a concrete additive
c) Sea dredged aggregates or aggregates for use in reinforced concrete
d) Asbestos cement products; or asbestos in any other form including
vermiculite containing asbestos fibrous dust
e) Lead or any products containing lead for use in connection with
f) Materials which are generally composed of mineral fibres either man
made or naturally occurring which have a diameter of 3 microns or
less and a length of 200 microns or less or which contain any fibres
not scaled or otherwise stabilized to ensure that fibre migration is
g) Urea formaldehyde
h) Plastics for water storage and delivery that release toxic materials
i) Materials containing vinyl chloride unless risk form carcinogen is
shown to be negligible.
j) Vermiculite containing asbestos fibrous dust
k) Cellulose fibre
l) Polyurethane foam or polyisocyanurate foam unless the risk is
shown to be negligible
m) Plywood with glues, resins and surface treatments that produce
irritant volatiles
n) Decorative finishes containing lead or asbestos
o) Materials containing chlorofluorocarbons (CFCs)
p) Paints and wood preservatives containing pentachlorophenois
(PCPs) tributyl tin oxide (TBTO) or Lindane.
q) Any treatment of materials either before or after installation which
give rise to toxic or hazardous emissions or particles
r) Any other substances generally known at the time of use to be
deleterious to health and safety or to the durability of the works in
the particular circumstances they are used.
1.5 Benchmarks
Prior to Commencement of Construction, the contractor shall in consultation
with the Engineer-In-Charge, establish several site datum benchmarks, their
number depending on the extent of the site. The benchmarks shall be sited
and constructed so as to be undisturbed throughout the period of
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
1.6 Site Investigation
The Engineer-In-Charge has got the soil investigation done and the copy of
the report is for guidance. The contractor shall however inspect the site and
study the findings from the trial pits or bores in order to assess the problems
involved in and methods to be adopted for excavation and earthwork. The
contractor shall ascertain for himself all information concerning the sub-soil
conditions, ground water table periods and intensity of rainfall, flooding of the
site and all data concerning excavation and earthwork.
1.7 Setting Out the Work
The contractor shall set out the works and during the progress of the building
shall amend any errors arising from inaccurate setting out.
During the execution of the work contractor must cross check his work with
the approved drawings. The contractor shall be responsible for all the errors in
this connection and shall have to rectify all defects and / or errors.
1.8 Cleaning Up and Handing Over
Upon completion of the work, all the areas should be cleaned. All floors,
doors, windows, surface and external development area etc. shall be cleaned
down in a manner, which will render the work acceptable to the Engineer-in-
Charge. All rubbish due to any reason shall be removed daily from the site
and an area of at least TEN METRES on the outer boundaries of the premises
will be cleaned by the contractor as a part of the contract. Upon completion of
the project, the contractor shall hand over to the Engineer-in-Charge the
A) Certified reports of tests (materials and workmanship)
B) Written guarantee and certificates and
C) Maintenance manuals
All materials and methods of tests shall conform to the latest CPWD
Specifications with upto date correction slips, rules, regulations and / or
specifications of the following authorities where specified herein as
applicable, Bureau of Indian Standards (BIS) or British Standards code of
practice (BS) in case no equivalent BIS is available. The Engineer-In-Charge
will have the option to have any of the materials tested and if the test result
shows that the materials do not conform to the specifications, such materials
shall be rejected.
1.10 For all RCC Works
Cement conforming to relevant IS Code i.e. IS: 8112 (with latest revision
& amendment) shall be used.
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
In case the Chlorides and/or Sulphates etc. are found in soil and/or
ground water more than the permissible limits, the selection of type of
Cement shall be based on the guidelines given in IS 456 as the direction
of Engineer-in-Charge.
Batch Mix Plant (BMC)
Design mix concrete shall be used from fully automatic & computerized
Batch Mixing Plant. The plant shall conform to BIS Code IS 4925 (latest
version with upto date amendments). The Batch Mixing Plant shall be of
adequate capacity minimum 30 m3/hr. or more.
The minimum cement content to be used for the job is as follows:-
M 15 240 KG/CUM
M 25 330 KG/CUM
M 35 370 KG/CUM
M 40 390 KG/CUM
1. These are minimum quantities of Cement to be used irrespective of
the design mix.
Reinforcement Steel: Corrosion Resistant Steel TMT bars of Fe 500
CRS or more grade/conforming to IS: 1786-2008, IS 13920-2016, IS
456-2000 with all latest editions with up to date amendments and
relevant CPWD specification shall be used.
1.11 Quality Control
The Contractor must ensure that the works conform to the quality
standards upto the satisfaction of the Engineer-in-Charge. The contractor
shall submit his quality enforcement plan for monitoring. The works, plant
and materials shall be subject to tests from time to time as per best
practices in the industry. Wherever mentioned in the Contract, the tests
must be carried out at the Contractor’s expense. The materials, fitting &
fixtures shall be procured from reputed make & vendor’s approved by
NBCC Ltd. The Contractor must also supply samples of such material to
the Engineer- in-Charge of NBCC Limited for approval and they must carry
out the laboratory & field tests as and when required by the Engineer-in-
charge of NBCC Limited and/or in conformity with relevant BIS-Codes.
1.12 General Specification
Water used in construction for all civil & structural works shall be clean
and free from injurious amount of oil, acids, alkalis, organic matters or
other harmful substances, which may be deleterious to concrete, masonry
or steel. The ph value of water sample shall be not less than 6. Potable
water shall be considered satisfactory.
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
Tests on water samples shall be carried out in accordance with IS: 3025
and they shall fulfill all the guidelines and requirements given in IS: 456.
The Engineer-in-Charge may require the Contractor to prove, that the
concrete prepared with water, proposed to be used, shall not have
average 28 days compressive strength lower than 90% of the strength of
concrete prepared with distilled water.
The Contractor is required to get the water tested from an approved
laboratory before starting the construction work and in case the water
contains any oil/organic matter or an excess of acid, alkalis or any
injurious amount of salts etc., beyond the permissible maximum limits
given in IS:456, the Engineer-in-Charge may refuse to permit its use. In
case there is any change in source of water, water samples shall be tested
again to meet the specified requirements.
Water shall be stored in tin barrels, steel tanks or water tight reservoirs
made with bricks/stone or reinforced concrete. Brick/stone masonry
reservoirs shall have RCC base slab and shall be plastered inside, with 1
part of cement and 4 parts of sand and finished with neat cement
punning. These reservoirs shall be of sufficient capacity to meet the water
requirements, at any stage of construction.
Water for curing shall be of the same quality as used for concreting and
masonry works. Sea water shall not be used for preparation of cement
mortar, concrete as well as for curing of plain/reinforced concrete and
masonry works. Sea water shall not be used for hydro testing and
checking the leakage of liquid retaining structures also.
Ordinary Portland cement of 43/53 grade conforming to IS 8112 / IS
12269 shall be used. Sulphate Resistant Cement shall be used for
Concrete works below the Plinth level.
Reinforcement Steel
Corrosion Resistant TMT bars of Fe 500 or more grade/conforming to IS:
1786 (latest edition) and IS 13920- 2016, IS 456:2000 (with update
amendments) and relevant CPWD specification shall be used.
In design calculation, stresses in reinforcement in Stirrups shall be taken
as 415N/mm2 as per IS: 456-2000 and other relevant Codes.
Materials of following specification are to be used in work. The Bidders are
expected to possess and be well conversant with the following IS standard
and code of practice.
Ordinary Portland Cement Conforming to IS
8112 / IS 12269 shall be used; Sulphate
Resistant Cement shall be used for all Concrete
works below the Plinth level.
2. Steel IS 1786, IS 456, IS 13920
3. Vibrator I.S. 7246
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
4. Aggregate I.S. 383, I.S. 515
Shall be clean, free from injurious amount of
Water for mixing oil, salt, acid, vegetable materials and other
and curing substances and harmful to concrete in
conformity to I.S. 456 and I.S. 3025.
7. Binding wire I.S. 280 (galvanized minimum 1.25 mm)
8. Rain water pipe I.S. 2527
9. Construction joints I.S. 3414
Steel Door Frame I.S. 4351/75
Conforming to I.S. 7452/82 strictly conform to
Fitting & Fixtures
I.S. specification and as per direction of
for joinery works
Engineer-in- Charge.
Note: In case of any doubt and absence of provision, regarding
specification, respective I.S. with latest amendments shall be referred
(Indian standard).
Items of Work included but not limited to the following:
1.12.1 Benchmark - Prior to Commencement of Construction, the contractor
shall in consultation with the Engineer-In-Charge, establish several
site datum benchmarks, their number depending on the extent of the
site. The benchmarks shall be sited and constructed so as to be
undisturbed throughout the period of construction.
1.12.2 Engineer-In-Charge has got the soil investigation done and the copy
of the report is for guidance. The contractor shall however inspect the
site and study the findings from the trial pits or bores in order to
assess the problems involved in and methods to be adopted for
excavation and earthwork. The contractor shall ascertain for himself
all information concerning the sub-soil conditions, ground water table,
periods and intensity of rainfall, flooding of the site and all data
concerning excavation and earthwork.
1.12.3 Setting Out: The contractor shall set out the works and during the
progress shall amend any errors arising from inaccurate setting out.
During execution of the work contractor must cross check his work
with the approved drawings. The contractor shall be responsible for all
the errors in this connection and shall have to rectify all defects and /
All materials and methods of tests shall conform to the latest CPWD
Specifications with upto date correction slips, rules, regulations and
/ or specifications of the following authorities where specified herein
as applicable, Bureau of Indian Standards (BIS) or British
Standards code of practice (BS) in case no equivalent BIS is
available. The Engineer-In-Charge will have the option to have any
of the materials tested and if the test result shows that the
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
materials do not conform to the specifications, such materials shall
1.12.5 Site quality control
The contractor shall provide in his quality assurance programme
information to show that a system will be used to ensure that all
works carried out under this section will comply with all the
requirements of this section
1.12.6 Antiquities
Any ancient carvings, relics, coins or other curiosities discovered
during the excavation or other work shall remain the property of
the Local Government and shall be handed over to NBCC.
1.12.7 Cleaning up and handing over
Upon completion of the work, all the areas should be cleaned. All
floors, doors, windows, surface and external development area etc.
shall be cleaned down in a manner, which will render the work
acceptable NBCC. All rubbish due to any reason shall be removed
daily from the site and an area of at least TEN METRES on the outer
boundaries of the premises will be cleaned by the contractor as a
part of the contract. Upon completion of the project, the contractor
shall hand over to NBCC the following.
A) Certified reports of tests (materials and workmanship)
B) Written guarantee and certificates and
C) Maintenance manuals
1.12.8 Earthwork in excavation & filling shall be done as per CPWD
Specifications with upto date correction slips. The Contractor shall
be responsible to take all necessary steps to prevent the sides of
trenches from caving in or collapsing. Contractor shall also make all
necessary arrangements for dewatering & drainage as required to
carry out proper excavation & other construction activities as
required and directed by the Engineer-in-Charge, by bailing or
pumping out water, which may accumulate in the excavation pit
either due to ground water, seepage, springs, rain or any other
cause/ source whatsoever. Dewatering of Pits shall be done with
methodology approved by the Engineer-in-Charge. Nothing extra
amount shall be claimed by the contractor on this account and his
quoted rates shall be deemed to have been included for total
dewatering, including sub-soil water also.
1.12.9 Plain and Reinforced Concrete shall be with conformity to I.S.456
and relevant BIS Codes/ CPWD Guidelines.
1.12.10 Cast in situ Reinforced Cement Concrete Piles shall be provided as
per approved drawings, IS Codes and as per latest CPWD
specifications with all amendments. Pile Load Test (Vertical Load
Test, Lateral Load Test, Pile Integrity Test, Pull Out Test on Piles)
shall be carried out in accordance with IS Code of practice IS :
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
2911 (Part IV) and as directed by the Engineer-in-Charge.
1.12.11 Foundation shall be with conformity to relevant BIS Codes/CPWD
Guidelines with up-to-date revisions & amendments.
1.12.12 All RCC works shall be done as per Drawings and CPWD
Specifications.
1.12.13 Reinforced Cement Concrete works upto Second floor level and
above Terrace level shall be executed with conventional shuttering
work as per CPWD Specifications.
1.12.14 Reinforced Cement Concrete works above Second floor level and
upto Terrace level shall be executed with customized Aluminium
Formwork as per CPWD Specifications. Aluminium Formwork shall
be using grade 5052 aluminium of panel sheets of minimum 4 mm
thick and grade 6061 (Type-6) aluminium for extruded sections.
Ready Mix Concrete confirming to IS 4926-1976 shall be used.
Specified strength based on 28-day compressive strength of 15-cm
cubes tested in accordance with IS: 456-1964 shall be the basis of
required RMC. Admixtures shall be as per CPWD Specifications with
upto date correction slips and relevant IS Codes
1.12.15 Corrosion Resistant Reinforced Steel of grade of Fe 500 or
more for reinforcement steel works and cutting, bending, binding in
position shall be done as per CPWD specifications.
1.12.16 The autoclaved aerated concrete blocks having oven dry density
550 to 650 kg/cum, fire resistance minimum 2 hours. Autoclaved
Aerated Blocks for masonry work shall be with conformity to
I.S.2185 Part-III and relevant BIS Codes/ CPWD Guidelines.
The blocks shall be stored on the site on a level ground, protected
against weathering.
Laying of mortar: the mortar shall not be spread so much ahead of
the actual laying of the units that it tends to stiffen and lose the
plasticity there by resulting in poor bond. Consistency as per
requirement of site must be maintained at the point of laying over
bed. Mortar joint shall be struck off flush with wall surface and
when the mortar starts stiffening, it shall be compressed tightly
1.12.17 Cement plastering shall be with conformity to relevant BIS Codes
and as per CPWD Specifications with upto date correction slips.
1.12.18 Mortar shall be with conformity to I.S.2250 and relevant BIS
Codes/CPWD Guidelines.
1.12.19 False Ceiling in Toilets: 8mm thick calcium silicate board false
ceiling with necessary frameworks shall be provided as per latest
CPWD specifications with all amendments.
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
1.12.20 Waterproofing for sunken portion & Under Ground Tank:
Cementitous water proofing as per latest CPWD Specification.
Specialized Agency shall be engaged for the work who is having at
least not less than five years’ of experience of similar nature &
minimum two works each of 60% quantum of the work. Prior to
engaging the agency, Approval of the specialized Agency for the
work has to be taken from the Engineer-in-Charge.
The contractor shall have to furnish ten years guarantee to maintain
the Water Proofing area.
1.12.21 Anti-Termite Treatment : Providing anti-termite treatment using
approved quality of chemical emulsion, spraying the mixture
uniformly by sprayer as pre-constructional anti-termite treatment and
creating a chemical barrier under and around the column pits, wall
trenches, top surface of plinth filling, junction of walls & floors along
with external perimeter of the building, expansion joints, surrounding
the pipes and conduits etc. complete at the rate as directed by the
manufacturer confirming to IS:6313 (Part-II) and as per direction of
Engineer-in-charge including cost of all materials, labour, taxes,
sundries, T&P etc. complete.
The Contractor shall have to furnish 10 years Guarantee to maintain
the anti- termite treated area/structures free from termite
1.12.22 All Stone work (Marble & Kota stone) shall be done as per CPWD
Specifications.
1.12.23 Flush Door Shutters (including minimum 25mm thick Teakwood
lipping) shall be provided and fixed as per relevant BIS
Codes/CPWD Guidelines. All accessories like handle, tower bolt,
door buffer, door stopper, shutter latch shall be made of Powder
coated Aluminium and to be provided/fixed as specified and
approved by Engineer-in-Charge.
1.12.24 Aluminium Doors & Windows :
Aluminium glazed doors, windows etc. shall be of sizes, sections
and details as shown in the drawings. The details shown in the
drawings may be varied slightly to suit the standards adopted by
the manufacturers of the aluminium work, with the approval of
Engineer-in-Charge. Before proceeding with any fabrication work,
the contractor shall Design to suit the load of wind pressure etc.,
prepare and submit complete fabrication and installation drawings
for each type of glazing doors, windows, ventilators and partition
etc. for the approval of the Engineer-in-Charge.
Aluminium, Polyester Powder coated (minimum thickness of powder
coating 60 micron) of approved color & shade, extruded sections of
approved manufacturers shall be used for fixed/openable windows,
ventilators, partitions, frame work & doors etc. shall be suitable for
use to meet architectural designs to relevant works and shall be
subject to approval of the Engineer-in-Charge for technical,
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
structural, functional and visual considerations. The aluminium
extruded sections shall conform to IS 733 and IS 1285 for chemical
composition and mechanical properties. The stainless steel screws
shall be of grade AISI 316. The permissible dimensional tolerances
of the extruded sections shall be as per IS 6477 and shall be such
as not to impair the proper and smooth functioning/operation and
appearance of door and windows. In case of Powder coating, The
powder used for powder coating shall be Epoxy/polyester powder of
make approved by the Engineer-in-Charge.
Glass of 6mm thickness to be used in glazing for openable and fixed
windows and 10mm thick toughened glass for doors etc. should
provide clear completely undistorted vision and reflection. It shall
be free from any bubbles, waves or blemishes. Glass used shall be
of required sizes as per Drawings.
All Gaps in between aluminium frame & adjacent RCC/ Brick/ Stone
work shall be filled up by providing weather silicon sealant over
backer rod of approved quality as per architectural drawings and
direction of Engineer-in-charge complete.
1.12.25 Precast Chequered tiles shall be provided as per latest CPWD
specifications with all amendments.
1.12.26 52mm thick Concrete flooring with non-metallic hardener shall be
provided as per as per latest CPWD specifications with all
amendments and Hardener as per manufacturer’s specifications.
1.12.27 Tremix flooring shall be provided as per latest CPWD specifications
with all amendments.
1.12.28 Floor level shall be maintained during casting of RCC slab to
accommodate the various types of flooring level. No extra payment
shall be made for this. Cement concrete screed of 1:2:4 mix of
required thickness shall be laid in true line and level to receive the
flooring (Tiles, stone etc.), for which nothing extra shall be payable.
1.12.29 All Painting works shall be done as per relevant IS Codes as per
latest CPWD specifications with all amendments.
1.12.30 All Mild Steel work like Railing, Door frames, Door shutter, Truss
etc. shall be as per latest CPWD specifications with all amendments.
1.12.31 Steel painting shall be with conformity to I.S. 1477 (Part-I & Part-
II) and relevant BIS Codes/CPWD Guidelines.
1.13 All works shall be executed as per latest CPWD specification document
with up to date correction slips (if any). Specifications not covered in
CPWD specifications are as under :-
a) All exposed surface of underground reinforced concrete element
shall be protected with two coats of Rubberised bitumen
waterproofing paint, the strokes of each layer to be opposite to
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
each other. Before painting the surface shall be thoroughly cleaned
to make the surface dust free.
b) Waterproofing for Roof : Specialized Agency shall be engaged for
the work who is having at least not less than five years’ of
experience of similar nature & minimum two works of 60%
quantum of the work. Prior to engaging the agency, Approval of the
specialized Agency for the work has to be taken from the Engineer-
in-Charge.. Water proofing of roof shall be executed as per
Specification detailed below:
APP Membrane (4mm thick Non-Woven Polyester
Reinforced) Waterproofing System-
Strictly comply with installation instructions in manufacturer’s
published literature, including but not limited to the following:
Cleaning the surface areas thoroughly so that they are free of all
contaminants like dirt and laitance & to remove all the loose
materials by various mechanical means. Removal of all surface
imperfections, protrusions, loose concrete & filling of cracks
using SBR latex modified Mortar in the ratio Cement: Sand (1:4)
and 5% by weight of cement.
The area of membrane to be laid in a working day should not
exceed that which can be effectively protected in the same
working period, in order to ensure that the membrane is not
subjected to any traffic. The Surface to be applied shall be
completely dry.
After due site preparation and cleaning apply the bituminous
primer at the consumption rate of 0.3 Kg/ Sqm or as specified
by the manufacturer depending on the porosity of the substrate.
Lay out the first complete roll of APP Membrane and align with a
chalk line set out on the floor.
Unroll one roll half way along the membrane to maintain
Fuse the thermo fusible film on the bottom side of the
membrane with a gas torch. When the film melts, immediately
roll the membrane forward and press firmly on the substrate to
Roll the applied membrane immediately with a wooden roller to
release any entrapped air.
Repeat this process with the second half of the roll
The next roll or length should be aligned against the previously
applied piece allowing for minimum 75mm side overlaps and
100 mm end overlap.
All edges and laps should be rolled to ensure proper contact and
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
bond of the laps.
On vertical sections ,
• After surface preparation apply Bitumen Primer at the
consumption rate of Kg/ Sqm depending on the porosity of the
• Terminate the first layer of APP membrane on parapet after
providing fillet of 50mm x50 mm) and fill it with approved
materials as per manufacturer and terminate membrane at min
300mm at FFL by making a groove of 20mm X20mm and
sealing the same with a bitumen sealant. , filling the groove by
• Providing and applying a protection plaster 12 – 15 mm thick
admixed with integral waterproofing compound of approved
make confirming to IS 2645.
Providing a protection screed of minimum 75 mm average
thickness laid in slope admixed with integral waterproofing
compound confirming to IS 2645 at the rate recommended by
the manufacturer. Screed shall be in 1:2:4 Cement Concrete
using of 125gms of synthetic Polyester triangular fibre (fibre of
length 12 mm effective diameters 10-40 microns and specific
gravity of 1.34 to 1.40) for 50 Kg cement used as per directions
of Engineer-in-Charge.
Required Nos. of Khurras shall be provided as per latest CPWD
specifications with all amendments
The contractor shall have to furnish ten years guarantee to maintain the
Water Proofing area.
c) Wooden Frames for Doors : Door frames shall be manufactured
and fixed as per drawings and CPWD specifications. Frames shall be
manufactured from seasoned good quality Red Mirandi wood.
d) PVC Doors for Toilets – PVC door shutters shall be minimum
24mm thick with necessary PVC frames as per manufacturer’s
specifications.
e) Tiling works on floors : Anti-skid/mat finish Ceramic Tile (size
600mm x 600 mm /300mm x 300mm) of approve make shall be
laid in flooring on leveled surface using approved quality Cement
based polymer modified tile adhesive (minimum 3mm thickness) of
approved make, uniformly as per manufacturer’s specifications in
line and level in approved design and filling the joints with epoxy
based joint filling compound of matching shade etc. complete in all
respect including cost of materials, carriage, all labour etc.
complete as per specification and direction of the Engineer-in-
f) All tile/stone flooring work shall be protected from any damage
Signature of Contractor NBCC
Construction of 600 Nos. (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
from the movement of any tools, plants, equipment at all times
during construction by use of a suitable strong, impervious film or
fabric securely held in place.
g) Tiling works on wall, skirting: Ceramic Tile (size 600mm x
600mm/ 450mm x 450 mm /300mm x 300mm) of approve make in
dados / skirting shall be fixed on plastered surface using approved
quality Cement based polymer modified tile adhesive (minimum
3mm thickness) of approved make, uniformly as per manufacturer’s
specifications in line and level in approved design and filling the
joints with epoxy based joint filling compound of matching shade
etc. Complete in all respect including cost of materials, carriage, all
labour etc. complete as per specification and direction of the
Engineer-in-Charge.
h) Fire Door : Providing & Fixing 46mm thick Fire check Door Frame
& Shutter of 2hr fire rating confirming to BS: 476 Part 22 and IS:
3614 Part II for stability and integrity. Fire doors should be tested
at CBRI Roorkee or equivalent Lab approved by the Engineer-in-
Charge for maximum rating of 2hrs with vision panel. Pressed
Galvanized steel Single/Double leaf door, shutter, infill and finish as
detailed below and conforming to IS 277 complete as per directions
of Engineer-in-charge. Door frame shall be single rebate profile of
125mm x 75mm made out of 1.60mm (16gauge) thick galvanized
steel sheet. Door Frames shall have butt joint and field assembled
with self-tabs / nut bolts. All provision should be mortised, drilled
and tapped for receiving appropriate hardware. Frames should be
provided with back plate bracket and anchor fasteners for
installation on a finished plastered masonry wall opening. Door to
be fixed with 2 hour fire rated stainless steel ball bearing hinges
125mm x 75mm x 3mm, in SS 316 (4 hinges per leaf of shutter).
Suitable for door weights upto 120kgs, Panic bar as per door leaf
(single leaf/ double leaf) Panic Hardware consisting of Main Panic
Latch component, End Component, Push bar, Striker Kit, end caps,
complete set with screws & fixing accessories, External trim, having
fire rated door closer TS 71/68 rack and pinion door closer EN size
3/4, with std. arm and with two independent closing valves and
latching speed adjustable by arm. Full plastic cover should be as
per EN 1154 life cycle 500,000 with seals and door stopper of
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
TECHNICAL SPECIFICATIONS
PLUMBING & SANITARY WORKS
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
The Employer Requirements - present the Contract Conditions, Requirements
of employer for 600 nos. 2BHK flats at residential building ‘Social Housing,
Hulhumale, Maldives. This section gives an overall description of the
construction specifications, some of the design standards and construction
methodology pertaining to PLUMBING & SANITARY SYSTEM.
The contractor shall wherever applicable shall refer equivalent Maldives
Euro/British Codes/Utility Regulation Authority Guidelines/MNDF Regulations
for various specifications of works laid out in this document. However, in case
of non-availability of codes in above mentioned documents for carrying out
any respective works as laid in this document, Indian Standards (Central
Public Works Department (CPWD) Specifications 2019 Volume I & II for
building works and Specification for Road and Bridge Works (Fifth Revision) –
2013, Ministry of Road Transport & Highways (MoRTH)) shall supersede. The
contractor in this case shall submit a Detailed Specifications document based
on relevant Maldives/ Euro or British Codes for approval from client before
execution. Items which are not covered in construction specification neither in
CPWD and MoRTH specification, same shall be executed as per sound
engineering practice and shall be approved by Engineer-In-Charge prior to
commencement of particular item
1.1. Drawings and Technical Documents
All the drawings are to be prepared in computer through AutoCAD which
should provide means of integrating with other discipline's models.
Drawings shall include layouts for pump room, typical toilets drawings showing
exact location of supports, flanges, bends, tee connections, reducers, detailed
piping drawings showing exact location and type of supports, valves, fittings
etc., external insulation details for pipe insulation, electrical panels
inside/outside views, power and control wiring schematics, cable trays,
supports and terminations.
These drawings should be containing all information required to complete the
design and Execution of the Works and also details of construction, size,
arrangement, operating clearances, performance characteristics and capacity
of all items of equipment including the details of all related items of work.
Each item of equipment/material proposed must be a standard catalogue
product of an established manufacturer from the list of approved makes.
Manufacturer’s drawings, catalogues, pamphlets and other documents are to
be maintained in the records office. Each item in each set shall be properly
labeled, indicating the specific services for which material or equipment is
used, giving reference to the governing section and clause number and clearly
identifying the items and the operating characteristics.
Samples of all materials like valves, pipes, insulation, control wires etc. are to
be maintained at site in a dedicated samples room.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
All plumbing system drawings shall be read in conjunction with civil and other
utility drawings.
1.2. Technical Data
Not with standing anything contained in the Employer’s Requirements, the
voltage rating for equipment shall be as follows:
• phase equipment: 433 V ±5%
• phase equipment: 230 V ±10%
2. Design Criteria
The plumbing System shall be designed to cater the entire footprint of the
residential facilities designed for 2BHK Residential construction. The system
should be capable of catering to the full load requirements.
3. Plumbing Systems
3.1. Distribution
Water distribution for the flats shall be carried out with the help of following:
• Installation, Testing & Commissioning of Hydro pneumatic pump
(minimum 3 Working +1 Standby) system for domestic water supply with
all necessary provisions for the same is deemed to be included in the
scope of work. (Hydro pneumatic pump system shall be supplied free of
• Pump shall be having minimum capacity of 410 LPM at 85 M head.
• The pumps shall be provided with the above hydro pneumatic system with
variable speed pumps which would automatically start on and off
depending on the applied load
The hydro pneumatic system envisaged is to operate on the principle of
sensing pressure variations in the plumbing network actuated by pressure
switches at pre-defined pressures in the system.
In case of marginal loads on the plumbing network during lean periods of
residential activities only predefined numbers of pump sets will run so as to
maintain adequate pumping pressures in the network. In the event of increase
in water supply demand, additional pump (s) shall cut-in to meet the
increased demand. This would facilitate optimizing the energy consumptions
without compromising on the performance requirements as opposed to
conventional water supply system. Also, optimization of power will be
achieved by using variable speed pumps which are automatically adjusted to
the varying demands.
The hydro pneumatic system will have inbuilt electronic control panels which
will facilitate pressure settings thereby protecting the system from excessive
pressures and the equipment from burn out. Also, this system would prevent
the occurrence of water hammer in plumbing system by varying the pressures
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
The water distribution system shall be provided at pump room at stilt level of
individual Tower. The water from the MWSC existing water supply line,
pipeline shall be connected to suction of hydro-pneumatic pumping system.
The water shall be distributed to individual flat from the individual line. From
the individual line, water shall be supplied to toilet & kitchen by the individual
3.2. Hot Water
Provision of Hot water supply for the master bed room toilets is to be
3.3. Sewer Drain Systems
System Concept
The system is designed for the following:
• Natural grading of the site.
• Layout of different facilities in the building
• Levels of road and other services in the Vicinity.
• Sub-soil water table.
• Soil conditions
Approach to Planning
The System is designed as a separated system for soil and waste water up to
the first manhole, based on conventional water carriage method.
From the first manhole, the combined sewage is to be conveyed by gravity
through a network of pipes and manholes up to the Plot boundary including
connection to the MWSC Trunk line/ manhole.
The drainage system is a 2-pipe system in accordance with the MWSC, in
which the soil and waste pipes are to be distinct and separate with
independent vents. The disposal from water closets is connected to the soil
stack and local manholes directly and the waste pipes through a trapped gully.
All traps of water closets and the urinals are completely vented in the system.
The vent pipe shall also to be connected to the manhole at ground level.
Design Criteria
The sewer drain system is designed in accordance with design criteria
stipulated in the MWSC published and National and International practices on
the subject. These criteria are as follows:
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
a. Flow of sewage : 80% of water supply (peak flow)
b. Peak flow : 3 times average flow
c. Min. diameter of pipe : 150/200 mm dia
d. Min. velocity in pipe : 0.6 mps
e. Max. velocity in pipe : 3 m / second
f. Flow conditions in pipes:
Pipes up to 400 mm dia : 0.50 full running
Pipes above 400 mm dia : 0.67 full running
Min. depth of pipe below
For branches : 0.6 m
For other : 1.0 m
Formula for calculation and
h. : Manning’s Formula
design of sewer lines
3.4 Rain Water Disposal
In general, the rain water from terraces shall be collected through the down-
take pipes connected to nearest storm water catch basin. Size of catch basin
shall be as per drawing approved with the complete requirement.
All plumbing installations must follow all relevant and prevailing rules, norms
and regulations.
Components should be labeled and numbered according to wiring diagrams.
The water distribution system is provided at pump room which is provided at
stilt level. The water from the MWSC existing water supply line, pipe is
connected suction of hydro-pneumatic pumping system. The water is
distributed to individual flat from the individual line. From the individual line,
water is supplied to toilet & kitchen by the individual pipe line.
3.6 Sanitary Fixtures & Fittings
General Requirement
Sanitary appliances and fixtures for toilets shall be chromium plated brass
fittings subject to approval from the employer’s representatives.
All fixtures and accessories are fixed in accordance with a set pattern
matching the tiles or interior finish. Wherever necessary, the fittings are
centered to dimensions and pattern.
Fasteners to be used shall be half round head chromium plated (CP) brass
screws with CP brass washers.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
All materials to be used shall be rust-proof. Materials in direct or indirect
contact are to be compatible to prevent electrolytic or chemical (bimetallic)
Joints / gaps between all sanitary appliances / fixtures and the floor / walls
shall be caulked with an approved mildew resistant sealant having antifungal
properties of color and shade to match that of the appliances / fixture and the
Water Closet
European W.C. of glazed vitreous China shall be wash down, single or double
siphonic type, floor mounted set, flushing by means of Low level PVC
flushing cistern as specified in the Bill of Quantities. Flush pipe/bend shall be
connected to the W.C. by means of suitable rubber adopter.
Each W.C. seat cover is to be so fixed that it remains absolutely stationary in
vertical position without falling down on the W.C. Seat cover shall be white
solid plastic, elongated open front with heavy duty hinges. Exposed fixture
trims shall be Chrome plated and trims of similar function shall be of the same
Flushing cistern provided for WC shall be low level PVC Cistern of approved
Wash basins shall be vitreous China and under counter in toilets.
Each basin is provided with CI brackets, clips and basin to be securely fixed to
Each basin is to be provided with 32mm diameter CP waste with overflow,
pop-up waste or rubber plug and CP brass chain. The drain outlet is connected
through CP bottle trap and the CP connector pipe.
Bottle trap (for wash basins, sinks etc.) shall be deep seal (minimum 60mm
water seal) cast brass Bottle, heavy chromium plated. All bottle traps are to
be provided with suitable cleaning eye, extension Piece, flare nuts, all
chromium plated. Bottle traps are of approved make and design. Traps for
washbasins, urinal and sinks shall be 32mm
HEALTH FAUCET
A chromium plated spray with integral hand control valve connected to a
flexible pipe and angle valve with wall flange and hook are to be provided as
shown on the drawings or as directed by the Project Manager.
2 WAY BIB TAP
These are chromium plated brass heavy quality of “EGO” type or equivalent,
and are easy type with capstan head. The size is as per design required.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
Double bowl Stainless steel (SS-316) Sinks shall be provided without drain
board based on the requirements.
Each sink is to be provided with painted MS or CI brackets and clips. Counter
top sinks is fixed with suitable painted angle iron brackets or clips. Each sink
is provided with 40mm dia CP waste and rubber plug with CP brass chain. The
MS angle is provided with two coats of red oxide primer and two coats of
synthetic enamel paint. The drain outlet is connected through CP bottle trap
and the CP connector pipe.
3.7 Water Supply (Cold & Hot)
3.7.1 Piping Materials
The piping system for all application other than concealed piping shall consist
of POLO-UV ML5 & POLO-POLYMUTAN ML5 PPr PE 80 GLASS REINFORCED
PIPES and fittings conforming to AS standards.
The piping system for vertical water supply is to be done with POLO-UV ML5 &
POLO-POLYMUTAN ML5 PPr PE 80 GLASS REINFORCED PIPES and fittings
conforming to applicable Code Requirements.
The piping system of internal UPONOR PEX or equivalent piping system with
brass lead-free fittings, NSF approved with crimp joints as required complete.
Galvanized Iron Pipes & Fittings
The pipes shall be galvanized mild steel welded (ERW) or (HFW) screwed and
socketed conforming to the requirements of MWSC. The galvanizing must be
conforming to MWSC with uniform zinc coating, adherent reasonably smooth
and free from such imperfections as flux, ash and drop inclusions, bare
patches, black spots, undulations, lumpiness, runs, rust strains, bulky white
deposits and blisters.
3.7.2 Piping Installation Support
Piping system is to be properly supported with supporting / hanging system as
per the standards.
Pipe work and fittings are to be supported by hangers or brackets allowing
free expansion and contraction. All accessories and ancillaries of support
system such as bracket, saddles, clamps, hanger etc. shall be hot dip
galvanized after fabrication. Further to permit free movement of common
piping, supports shall be from a common hanger bar, fabricated from
galvanized steel sections.
Pipe hangers shall be provided at the following maximum spacing:
Pipe Dia (mm) Hanger Rod Dia mm) Spacing between Supports
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
Insulated piping shall be supported in such a manner that there will be no
undue pressure on the insulation. 14-gauge metal sheets are to be provided
between the insulation and the clamp, saddle or roller, extending at least 15
cm on both sides of the clamps, saddles or roller.
Pipe sleeves, larger diameter than pipes are to be provided wherever pipes
pass through walls and slab and annular space filled with fibre glass and
finished with retainer rings.
All buried pipes for CWS must be cleaned and coated with two coats of
bitumen and then wrapped with two layers of 400-micron polythene sheet
Automatic air valves shall be provided at the top of pipe. All high points in the
piping system are with venting. Vent valves are 15mm pipe size and are
associated with an equal size isolation ball valve.
Discharge from the air valves shall be piped through a galvanized steel pipe to
the nearest drain or sump. All pipes are pitched towards drain points.
Pressure gauges are to be provided at required locations.
The ferrules for connection with main piping system shall be generally
conforming to MWSC. It’s of non-ferrous materials with a bell mouth cover
and is of nominal bore. The ferrule if fitted with a screw and plug or valve
capable of completely shutting of the water supply to the communication pipe,
as and when required.
3.9 Water Meters
The water meters should be conforming to requirements stated by the
Respective Local Authorities. Suitable valves and chambers or wall meter box
to house the meters are to be provided along with the meters.
The meters must be conforming to MWSC.
All water supply system are to be tested to hydrostatic pressure of at least
one and a half (1.5) times the maximum working pressure but not less than
10 Kg /cm2 for a period for not less than 4 hours.
System may be tested in sections and such sections are entirely to be re-
tested as a complete network on completion of total works.
All valves (gate, globe, check, safety) are of gun metal suitable for the
particular service. All valves are of the particular duty and design. Valves all
either shall be of screwed type or flanged type, with suitable flanges and non-
corrosive bolts and gaskets. Tail pieces are to be supplied along with valves.
Gate, globe and check valves must be conforming to local standard and non-
return valves and swing check type reflux to local standard.
Sluice valves, where specified shall be flanged sluice valves of cast iron body.
The spindle, valve seat and wedge nuts shall be of gunmetal. They are
generally have non-rising spindle and are of the particular duty and design.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
The valves are to be supplied with suitable flanges, non-corrosive bolts and
asbestos fibre gaskets. Sluice valves shall be conforming to local standard.
Ball valves with floats to be fixed in storage tanks shall consist of cast brass
lever arm having copper balls (26 SWG) screwed to the arm integrally. The
copper ball is bronze welded seams. The closing/opening mechanism
incorporating the piston and cylinder is non-corrosive metal and include
washers. The size and construction of ball valves and float is suitable for
desired working pressure operating the supply system. Brass valves are
supplied with brass hexagonal back nuts to secure them to the tanks and a
socket to connect to supply pipe.
Globe valves on water line are union bonnet with stem/disc and body seat ring
of SS-316. Suitable for temperature up to 80° C.
Sl No Type of Valve Size Construction Ends
15 mm to 50 mm Gun Metal Screwed
a. Isolating Valve
65 mm and above Gun Metal Flanged
b. 65 mm and above Cast Iron Flanged
Butterfly Valve
G.M. non return 15 mm to 50 mm Gun Metal Screwed
valve 65 mm above Gun Metal Flanged
Flap Type – Non
d. 65 mm and above Cast Iron Flanged
All valves are suitable for the working pressure involved.
3.11.1 Pressure Reducing Valve Set
Each pressure reducing valve set is complete with pressure reducing or
pressure regulating valve, isolating valves, pressure gauges on inlet and
outlet, pressure relief valve on outlet and filter on inlet.
Each pressure reducing valve is comprising of loading neoprene diaphragm
and a full floating, self-aligning, ignition resistant seat and is of the single
stage, pressure reduction type with provision for manually adjusting the
delivery pressure. The valve should not fail to the low pressure.
Valves should be capable of operating and maintaining automatically the
respective delivery pressure and flow rates and are not be liable to creep.
Valves are also to be capable of maintaining the pre-set downstream pressure
under static condition.
The filter on each inlet to a pressure reducing valve shall be of replaceable
porous sintered metal type.
3.12 Pressure Gauge
The pressure gauge shall be constructed of die cast aluminium and stove
enameled. It’s weather proof with an IP 55 enclosure. It’s a stainless steel
(SS-316 grade) bourdon tube type pressure gauge with a scale range from 0
to 16 Kg / Sq.cm. and shall be constructed in accordance with international
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
code. Each pressure gauge shall have a siphon tube connection. The shut off
arrangement shall be by ball valve.
3.13 Water Fittings
All gunmetal fittings such as gate, globe, check and safety valves are to be
fitted in pipe line as per the requirements for efficient operation of water
distribution system. Necessary unions are to be provided on both ends of the
valves for the purpose of easy replacement.
3.14 Connections to RCC Water Tanks
All pipes crossing through RCC work must have puddle flanges fabricated from
GI pipes of required size and length and welded to 6/8 mm thick GI plate. All
puddle flanges must be fixed in true alignment and level to ensure further
connection in proper order.
Full way gate valves of approved make are to be provided as near the tank as
practicable on every outlet pipe from the storage tank except the overflow
pipe. Overflow and vent pipes are to be terminated with mosquito proof
The overflow pipe shall be so placed to allow the discharge of water being
readily seen. A stop valve is also to be provided in the inlet water connection
to the tank. The outlet pipes are to be fixed approximately 75mm above the
bottom of the tank towards which the floor of the tank is sloping to enable the
tank to be emptied for cleaning.
3.15 Pipe Protection (For Cold Water Pipes Buried In Trenches / Ground /
All buried pipes are to be cleaned with zinc chromate primer and AW4 pypkote
protection shall be applied.
3.16 Thrust Blocks
In case of bigger pipes (80 mm dia and above), thrust blocks of cement
concrete 1:2:4 (1 cement: 2 coarse sand: 4 graded stone aggregate of 20
mm nominal size) shall be constructed at all bends.
3.17 Masonry Chamber
• All masonry chambers for stop cocks, sluice valves and meter etc. are to
be built based on the requirement.
• Concrete means cement concrete 1:3:6 (1 cement: 3 coarse sand: 6
graded stone aggregate 40 mm nominal size for bottom and cement
concrete 1:2:4 (1 cement: 3 coarse sand: 6 graded stone aggregate 20
mm nominal size for top slab.
• AAC Block masonry in cement mortar 1:5 (1 cement: 5 fine sand)
• Inside Plaster shall be minimum of 12 mm thick in cement mortar 1:3 (1
cement: 3 fine sand) finished with a floating coat of neat cement.
3.18 Internal Drainage (Soil, Waste, Vent & Rain Water Pipes)
3.18.1 Piping System
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
Scope of work
• Work under this section consists of furnishing all labour, materials,
equipment and appliances necessary and required to completely install all
soil, waste, vent and rainwater pipes and fittings as required by the
approved drawings.
• Without restricting to the generality of the foregoing, the soil, waste, vent
pipes system includes the following: -
o Vertical and horizontal soil, waste, vent pipes, and fittings, joints,
clamps, connections to fixtures.
o Connection of all pipes to sewer lines as shown on the drawings at
ground floor levels.
o Drainage, channels, gratings & floor drains.
o Floor and urinal traps, cleanout plugs, inlet fittings and rainwater
heads/Khurras Testing of all pipe lines
3.18.2 General requirements
• All materials shall be new and of the best quality conforming to
specifications and subject to the approval of Project Manager.
• Pipes and fittings must be fixed truly vertical, horizontal or in slopes as
required in a neat workmanlike manner.
• Pipes shall be fixed in a manner as to provide easy accessibility for repair
and maintenance and not cause obstruction in shafts, passages etc.
• Pipes must be securely fixed to walls and ceilings by suitable clamps
intervals specified.
• Access doors for fittings and clean outs shall be so located that they are
easily accessible for repair and maintenance. Any access panel required in
the civil structure, false ceiling or marble cladding etc. are clearly reported
to the Employer in the form of shop drawing so that other agencies are
instructed to provide the same.
3.18.3 Piping System
Schedule of Pipes Use
1 uPVC pipes 75, 110,
Vertical stacks for Soil, Waste, Vent & RWP
160 & 210 mm dia
2 uPVC pipes 40, 50 & Horizontal For Soil, Waste. Vent pipes pvc
63 mm dia pipes (welded joints) 6 kg/sqcm class III
3.18.4 Soil, Waste & Vent Pipes
• The Soil & Waste Pipe System above ground has been planned as a "two
pipe system" as defined in MNWS having separate pipes for waste for
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
kitchen sinks, showers, washbasins and floor drains and is approved by
Project Manager.
• All waste water from pump rooms, floor channels are to be provided with a
deep seal trap before connecting to the main drain or vertical stack.
• Vertical soil & waste stacks shall be connected to a separate horizontal
drain at ground level generally as shown on the approved drawings.
• Toilet layouts have been so arranged that the W.C. outlets are with “P”
trap above ground.
3.18.5 Rainwater Pipes
• All open terraces are drained by rain water down takes.
• Rainwater down takes shall be separate and independent of the soil and
waste system and are to discharge into Catch Basin/harvesting pits/
Drainage system of the Complex.
• Rain water in open courtyards are collected in catch basins and connected
to the storm water drain.
• Any dry weather flow from waste appliances e.g. waste water sumps shall
be connected to sewers after traps and not in the storm water drainage
3.18.6 Balcony drainage
Wherever required, all balconies, terraces, planters and other formal
landscape areas are to be drained by vertical down takes or other type of
drainage system shown on the approved drawings and directed by the
Architect/Project Manager
3.18.7 uPVC Pipes & Fittings
• Soil, Waste and Anti-siphonage pipes and fittings are uPVC. All pipes are
straight and smooth conforming to MWSC or as specified in approved
• Pipes and fittings for main vertical stacks & branches 110 mm, & 75 mm
dia are Soil, Waste & Rainwater System known in the short form as SWR
drainage system with injection moulded fittings with approved type of
socket & ‘O’ rubber ring joints.
• Joints are done as per the manufacturer’s recommendations. The pipes and
fittings must have matching dimension for perfect joints in the system. ‘O’
ring fittings must have sufficient gap (approx. 10 mm) for thermal
expansion of pipes.
• uPVC pipes are to be clamped to the wall with approved type uPVC saddle
clamps/U clamps and G.I. rod fixed to the angle iron support system within
• Use proper uPVC pipe adapters for connections between cast iron pipes,
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
traps & uPVC pipes where necessary. Such joints are made of an approved
type of ‘Putty’.
For UPVC pipes standard UPVC clamps are used. For other pipes M.S.
clamps, supports and hangers provided are galvanized. Factory made Pre-
fabricated clamps are preferred. Contactor may fabricate the clamps of special
nature and galvanize them after fabrication but before installation. (Clamps
are fabricated from mild steel sections) All nuts, bolts, washers and other
fasteners are factory galvanized.
• Clamps shall be of approved designs and fabricated from M.S. flats and
other sections of thickness and sizes as per drawings or contractor’s
shop drawings. Clamps are fixed in accordance to manufacturer’s
details/shop drawings to be submitted by the contractors.
• When required to be fixed on RCC columns, walls or beam are to be
fixed with approved type of galvanized expansion anchor fasteners
(Dash fasteners) of approved design and size according to load.
• Structural clamps e.g. trapeze or cluster hangers fabricated by electro-
welding from M.S. Structural members e.g. rods, angles, channels,
flats as per Contractors shop drawing are to be galvanized after
fabrication. All nuts, bolts and washers must be galvanized.
• Galvanized slotted angle/channel supports on walls are provided
wherever shown on drawings. Angles/ channels are of sizes shown on
approved drawings. Angles/channels are fixed to brick walls with bolts
embedded in cement concrete blocks and to RCC walls with anchor
fasteners mentioned above. The spacing of support bolts on support
members fixed horizontally is not exceeding 1 m.
3.19.1 Floor traps
Floor traps where specified are of multi inlet uPVC traps (SWR) having a
minimum 50 mm deep seal. The trap and waste pipes when buried below
ground is set and encased in cement concrete blocks firmly supported on firm
ground or when installed on a sunken RCC structural slab. The blocks are in
1:2:4 mix (1 cement: 2 coarse sand: 4 stone aggregate 20 mm nominal size).
Contractor shall provide all necessary shuttering and centring for the blocks.
Size of the block is 30x30 cm of the required depth.
3.20 Cleanout plugs
Floor Clean out Plug.
Clean out plug for Soil, Waste or Rainwater pipes laid under floors shall be
provided near pipe junctions, bends, tees, “Y’s” and on straight runs at such
intervals as required as per site conditions. Cleanout plugs shall terminate
flush with the floor levels. They will be threaded and provided with key holes
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
for opening. Cleanout plugs shall be Cast Brass screwed to a G.I. socket. The
socket is lead caulked to the drain pipes.
3.21 Waste pipe from appliances
• Waste pipe from appliances e.g. washbasins, sinks and urinals shall be
uPVC in all toilets, kitchen, pantries and service areas where so required,
and as given in the Schedule of Quantities or shown on the drawings.
• All pipes are to be fixed in gradient towards the connection to stack, trap
or drain. Pipes inside all toilets shall be in chase unless otherwise shown
on approved drawings where so required and shown on drawings or
directed by the Project Manager.
• Galvanized pipes (Where specified or required at site for waste only)
conforming to MWSC (medium class) and quality certificates are
furnished. Pipes are to be provided with all required fittings e.g. tees,
couplings, bends, elbows, unions, reducers, nipples, plugs. All G.I. waste
pipes are to be terminated at the point of connection with the appliance
with an outlet of suitable diameter. Pipes in chase shall be painted with
two coats of black bitumen paint and exposed pipes with one coat of
red oxide primer and two or more coats of synthetic enamel paint or as
given in the Schedule of Quantities.
Laying and Jointing
The pipes are laid and clamped to wooden plugs fixed above the surface of the
wall. Provision is made for the effect of thermal movement by not gripping or
disturbing the pipe at supports between the anchors for suspended pipes. The
supports are allow the repeated movements to take place without abrasion.
Jointing for UPVC pipes are made by means of solvent cement for horizontal
lines and ‘O’ rubber ring for vertical line. Where UPVC pipes are to be used for
rain water pipes, the pipe is finished with GI adopter for insertion in the RCC
slab for a water proof joint.
UPVC pipes require supports at close intervals. Recommended support spacing
for un-plasticized PVC pipes is 1400 mm for pipes 50 mm diameter and above.
Pipes are aligned properly before fixing them on the wooden plugs with
clamps. Even if the wooden plugs are fixed using a plumb line, pipe also be
checked for its alignment before clamping, piping are properly supported on,
or suspended from clamps, as required. Pipe supports are primer coated with
anti-corrosive.
3.22 Pipes Hangars, Supports, Clamps Etc.
All pipes clamps, supports and hangers shall be galvanized. Factory made
prefabricated clamps are preferred. All nuts, bolts, washers and other
fasteners are factory galvanized.
Structural clamps e.g. trapeze or cluster hangers shall be fabricated by
electro-welding from MS structural members e.g. rods, angles, channels flats
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
and galvanized after fabrication. All nuts, bolts and washers shall be
3.23 Rain Water Pipes
All open terraces are drained by rain water down takes UPVC.
Rainwater down takes are separate and independent of the soil and waste
system and is discharge into the underground storm water drainage system of
Rainwater in open courtyards are collected in catch basins and connected to
the storm water drains.
Any dry weather flow from waste appliances, e.g. AHU’s pump rooms, waste
water sumps are connected to sewers after traps and not in the storm water
drainage systems.
3.24 Pipe Sleeves
Pipe sleeves, next larger diameter than pipes are provided wherever pipes
pass through walls and slabs and annular space filled with fiberglass and
finished with retainer rings. All pipes are accurately cut to the required sizes in
accordance with relevant BIS codes and burrs removed before laying. Open
ends of the pipes are closed as the pipe is installed to avoid entrance of
foreign matter.
3.25 Pipe Protection
Cast iron soil and waste pipes under floor in sunken slabs and in wall chases
(when cut specially for the pipe) are encased in cement concrete 1:2:4 mix (1
cement: 2 coarse sand: 4 stone aggregate of 12 mm size) 10 cm bed and
around. When pipes are running well above the structural slabs, the encased
pipes are supported with suitable cement concrete pillars of required height
Soil, waste, vent and rain water pipes in exposed location, in shafts and pipe
space shall be painted with two or more coats of ready mix oil paint to give an
even shade. Before painting all dust and extraneous matter are to be
Pipe in chase is painted with two coats of bitumen paint, covered with
polythene tape and a final coat of bitumen paint.
CI Soil and waste pipes below ground and covered in cement concrete are not
3.27 Commissioning
3.27.1 Pre-commissioning
The water storage tanks and pipes are first be filled with water and thoroughly
flushed out. The storage tanks are then be filled with water again and
disinfecting chemical containing chlorine added gradually while tanks are
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
being filled to ensure thorough mixing. Sufficient chemical is used to give
water a dose of 50 parts of chlorine to one million parts of water.
If ordinary bleaching powder is used, the proportions are 150 gm. of powder
to 1000 liters of water. The powder are mixed with water in the storage tank.
If a proprietary brand of chemical is used, the proportions are specified by the
manufacturer. When the storage tanks are full, the supply is stopped and all
the taps on the distributing pipes are opened successively working
progressively away from the storage tank. Each tap is closed when the water
discharged begins to smell of chlorine. The storage tank is then be filled up
with water from supply pipe and added with more disinfecting chemical in the
recommended proportions. The storage tank and pipe are then remain
charged at least for three hours. Finally, the tank and pipes are thoroughly
flushed out before any water is used for domestic purpose.
• The pipework is to be thoroughly flushed before supply is restored.
• After the pipework is tested and approved, but before it is coupled, it is
to be sterilized with a solution of chloride of lime.
• Prior to start-up and hydraulic testing, all pumping systems are to be
flushed and drained at least once thoroughly to get rid of contaminating
materials. All pipes are to be rodded to ensure clearance of debris,
cleaning and flushing are carried out.
• All strainers are to be inspected and cleaned out or replaced.
• When the entire systems are reasonably clean, a pre-treatment
chemical shall be introduced and circulated for at least 8 hours.
• Remove oil, grease and foreign residue from the pipework and fittings;
• Pre-condition the metal surfaces to resist reaction with water or air.
• Establish an initial protective film;
• After pre-treatment, the system is drained and refilled with fresh water
and left until the system is put into operation.
o Check all clamps, supports and hangers provided for the pipes.
o Check all the equipment, piping and valves coming under hot water
system and operate each and every valve on the system to see if
the valves are functioning properly.
o Fill up pipes with water and apply hydrostatic pressure to the
3.28 EXTERNAL SEWERAGE & DRAINAGE
3.28.1 Excavation
3.28.1.1 Alignment and grade
The sewer pipes shall be laid to alignment and gradient shown on the
drawings but subject to such modifications as shall be ordered by the Project
Manager. No deviations from the lines, depths of cutting or gradients of
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
sewers shown on the plans and sections shall be permitted except by the
express direction in writing of the Project Manager.
3.28.1.2 Excavation in tunnels
The excavation for sewer works shall be open cutting unless the permission of
the Project Manager is obtained for laying pipes in tunnel where sewers have
to be constructed along narrow passages or difficult ground.
3.28.1.3 Opening out trenches
In excavating the trenches, etc. the solid road metalling, pavement, kerbing,
etc. and turf is to be placed on one side and preserved for reinstatement when
the trenches or other excavation shall be filled up. Before any road metal is
replaced, it shall be carefully sifted. The surface of all trenches and holes shall
be restored and maintained to the satisfaction of the Project Manager.
The Contractor shall grub up and clear the surface over the trenches and other
excavations of all trees, stumps roots and all other encumbrances affecting
execution of the work and shall remove them from the site to the approval of
the Project Manager.
3.28.1.4 Obstruction of roads
The Contractor shall not occupy or obstruct by his operation more than one
half of the width of any road or street and sufficient space shall then be left
for public and private transit, he shall remove the materials excavated and
bring them back again when the trench is required to be refilled. The
Contractor shall obtain the consent of the Project Manager.
3.28.1.5 Removal of filth
All night soil, filth or any other offensive matter met with during the execution
of the works, immediately after it is taken out of any trench, sewer or cess
pool, shall not be deposited on to the surface of any street or where it is likely
to be a nuisance or passed into any sewer or drain but shall be at once put
into the carts and removed to a suitable place to be provided by the
3.28.1.6 Excavation to be taken to proper depths
The trenches shall be excavated to such a depth that the sewer shall rest on
concrete as described in the several clauses relating thereto and so that the
inverts may be at the levels given in the sections.
3.28.1.7 Refilling
After the sewer or other work has been laid and proved to be water tight, the
trench or other excavations shall be refilled. Utmost care shall be taken in
doing this, so that no damage shall be caused to the sewer and other
permanent work. The filling in the haunches and upto 75 cms above the
crown of the sewer shall consist of the finest selected materials placed
carefully in 15 cms layers and flooded and consolidated. After this has been
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
laid, the trench and other excavation shall be refilled carefully in 15 cms
layers with materials taken from the excavation, each layer being watered to
assist in the consolidation..
3.28.1.8 Contractor to restore settlement and damages
The Contractor shall, at his own costs and charges, make good promptly
during the whole period the works are in hand, any settlement that may occur
in the surfaces of roads, berms, footpaths, gardens, open spaces etc. whether
public or private caused by his trenches or by his other excavations and he
shall be liable for any accidents caused thereby. He shall also, at his own
expense and charges, repair and make good any damage done to buildings
and other property if in the opinion of the Project Manager the damage is due
to his negligence.
3.28.1.9 Disposal of surplus soil
The Contractor shall at his own costs and charges provide places for disposal
of all surplus materials not required to be used on the works. As each trench
is refilled the surplus soil shall be immediately removed, the surface properly
restored and roadways and sides left clear.
3.28.1.10 Timbering of sewer and trenches
a) The Contractor shall at all times support efficiently and effectively the sides of
the sewer trenches and other excavations by suitable timbering, piling and
sheeting and they shall be closed timbered in loose or sandy strata and below
the surface of the sub soil water level.
b) All timbering, sheeting and piling with their walling and supports shall be of
adequate dimensions and strength and fully braced and strutted so that no
risk of collapse or subsidence of the walls of the trench shall take place.
3.28.1.11 Shoring of buildings
The Contractor shall shore up all buildings, walls and other structures, the
stability of which is liable to be endangered by the execution of the work and
shall be fully responsible for all damages to persons or property resulting from
3.28.1.12 Removal of water from sewer, trench etc.
a) The Contractor shall at all times during the progress of the work keep the
trenches and excavations free from water which shall be disposed of by him in
a manner as will neither cause injury to the public health nor to the public or
private property nor to the work completed or in progress nor to the surface of
any roads or streets, nor cause any interference with the use of the same by
b) If any excavation is carried out at any point or points to a greater width than
the specified cross section of the sewer with its envelope, the full width of the
trench shall be filled with concrete by the Contractor at his own expenses and
charges to the requirements of the Project Manager.
3.28.1.13 Width of trench
Recommended width of trenches at the bottom shall be as follows: -
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
100 mm dia pipe 55 cms
150 mm dia pipe 55 cms
225-250 cms dia pipe 60 cms
300..400 mm dia pipe 75 cm
Maximum width of the bed concrete shall also be as above. No additional
payment is admissible for widths greater than specified.
3.28.2 Gully traps
Gully traps shall be of the same quality as described for stoneware pipes in
clause 4.1 above and used where shown on drawings.
Gully traps shall be fixed in cement concrete 1:5:10 mix and a brick masonry
chamber 30x30 cms inside in cement mortar 1:5 with 15x15 cms grating
inside and 30x30 cms C.I. sealed cover and frame weighing not less than 7.3
kg to be constructed as per standard drawing. Where necessary, sealed cover
shall be replaced with C.I. grating of the same size (1 cement: 5 coarse sand:
10 stone aggregate 40 mm nominal size.
3.28.3 Cement concrete and masonry works (for manholes and chambers
3.28.3.1 Materials
Water used for all the constructional purposes shall be clear and free from oil,
acid, alkali, organic and other harmful matters, which shall deteriorate the
strength and/or durability of the structure. In general, the water suitable for
drinking purposes shall be considered good enough for constructional purpose.
b) Aggregate for concrete
The aggregate for concrete shall be in accordance with NFPA. In general,
these shall be free from all impurities that may cause corrosion of the
reinforcement. Before actual use these shall be washed in water, if required as
per the direction of Project Manager. The size of the coarse aggregate shall be
done as per NFPA.
Sand for various constructional purposes and its grading shall comply in all
respects with NFPA. It shall be clean, coarse hard and stone, sharp, durable,
uncoated, free from any mixture of clay, dust, vegetable matters, mica, iron
impurities soft or flaky and elongated particles, alkali, organic matters, salt,
loam and other impurities which may be considered by the Project Manager.
The cement used for all the constructional purposes shall be ordinary Portland
cement or rapid hardening Portland cement.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
e) Mild steel reinforcement
The mild steel for the reinforcement bars shall be in the form of round bars
conforming to all requirements.
The autoclaved aerated concrete blocks having oven dry density 550 to 650
kg/cum, fire resistance minimum 2 hours. Autoclaved Aerated Blocks for
masonry work shall be with conformity to I.S.2185 Part-III and relevant BIS
Codes/ CPWD Guidelines.
g) Other materials
Other materials not fully specified in these specifications and which may be
required in the work shall conform to the NFPA. All such materials shall be
approved by the Project Manager.
3.28.3.2 Cement concrete (plain or reinforced)
a) Cement concrete for pipes bedding, cradles, foundations and R.C.C. slabs for
all works shall be mixed by a mechanical mixer where quantities of the
concrete poured at one time permit. Hand mixing on properly constructed
platforms may be allowed for small quantities by the Project Manager. Rate for
cement concrete shall be inclusive of all shuttering and centring at all depth
b) Concrete work shall be of such thickness and mix as given in the Schedule of
c) All concrete work shall be cured for a period of at least 7 days. Such work
shall be kept moist by means of gunny bags at all times.
3.28.3.3 Masonry work
Masonry work for manholes, chambers and such other works as required shall
be constructed with autoclaved aerated concrete blocks as specified in the
approved drawings in cement mortar of mix as specified. All joints shall be
properly raked to receive plaster.
3.28.3.4 Cement concrete for pipe support
a) Wherever specified or shown on the drawings, all pipes shall be supported in
bed all round or upto haunches. The thickness and mix of the concrete shall
be given in the approved drawings. Width of the bedding shall be the width of
the trench as specified.
b) Unless otherwise directed by the Project Engineer, cement concrete for bed,
all-round or in haunches shall be laid as follows: -
Upto 1.5 m Upto 3.0 m
Beyond 3.0 m Depth
1:4:8 (no sub soil
Mix of concrete 1:4:8 1:4:8
UPVC pipes All round Upto Haunches All round
Mix of concrete 1:3:6 1:3:6 1:3:6
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
UPVC pipes All round All round All round
Under the building 1:3:6 1:3:6 1:3:6
UPVC pipes All round All round All round
(Concrete mix refer to cement: coarse sand: stone aggregate 40 mm
c) Upvc pipes may be supported on AAC Block masonry or precast R.C.C. or in
situ cradles. Cradles shall be as shown on the drawings.
d) Pipes in loose soil or above ground shall be supported on AAC Block or stone
masonry pillars as shown on the drawings.
3.28.3.5 Manholes and chambers
All manholes, chambers and other such works as specified shall be
constructed in AAC Block masonry in cement mortar 1:5 (1 cement: 5 coarse
sand) or as specified in the Schedule of Quantities.
All manholes and chambers etc. shall be supported on base of cement
concrete of such thickness and mix as shown on the drawings.
Where not specified manholes shall be constructed as follows: -
(All dimensions internal clear in cms)
Size of manhole 90 dia 122 dia
at bottom at bottom
Type Rectangular Rectangular Conical Conical
Maximum Depth 150 240 167 239
Average thickness
Size of cover and 60 x 45 50 dia 50 dia 50 dia
Frame mm 116 or 116 or 116 or 116 or
Weight of cover and
All manholes shall be provided with cement concrete benching in 1:2:4 mix (1
cement: 2 coarse sand: 4 stone aggregate 20 mm nom. Size) The benching
shall have a slope of 10 cm towards the channel. The depth of the channel
shall be full diameter of the pipe. Benching shall be finished with a floating
coat of neat cement. as per standard details.
All manholes shall be plastered with 12/15 mm thick cement mortar 1:3 (1
cement: 3 coarse sand) and finished with a floating coat of neat cement
inside. Manhole shall be plastered outside as above but with rough plaster
mixed with water proofing compound.
All manholes with depths greater than 0.8m shall be provided with 20 mm
square or 25 mm round rods aoristic coated catch rings set in cement
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
concrete blocks 25x10x10 cms in 1:2:4 mix 30 cms vertically and staggered.
Foot rests shall be coated with coal tar before embedding.
All manholes shall be provided with cast iron/steel fibre reinforced plastic
(SFRC) covers and frames and embedded in reinforced cement concrete slab.
Weight of cover, frame and thickness of slab shall be as specified in the
Schedule of Quantities or given above.
Road gullies, gratings on drains shall be cast iron with M.S. frame or Steel
Fibre Reinforced Concrete (SFRC) with frame as specified in the approved
drawings / Schedule of Quantities.
3.28.4 Making connections
Contractor shall connect the sewer line of the building to the main manhole by
providing making holes and channels etc.
3.28.5 Measurement
Rates are deemed to be inclusive but not limited to the followings:
a) All kinds of soil including rocks
b) Depth of excavation upto any depth including backfilling, consolidation etc.
c) Timbering and shoring, if required for all depths and types of soil
classifications.
d) Pumping and bailing out water from excavated pits and surface water from
rain falls or broken pipes lines and other similar sources.
Nothing Extra shall be payable on any account whatsoever detailed above.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
TECHNICAL SPECIFICATIONS
FIRE FIGHTING WORKS
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
1. Fire Fighting System
1.1. Classification of Buildings
All residential building is classified as per the MNDF guidelines & NFPA and
also attention is made to the guidelines stated. It is to design the firefighting
system considering the stringent of requirements stated between NFPA &
MNDF following buildings is classified according to the use or character of the
1.2. Wet riser System
The infrastructure for firefighting operation is considering wet riser system in
accordance with guidelines laid down by and as described in MNDF and is
consisting of following (minimum requirement):
• Hydrant pump.
• Jockey pump.
• Diesel engine driven pump.
Suction line of each pump is directly connected to the fire reserve tanks and
discharge is in a common header. 4 Kg/cm2 residual head pressure is to be
maintained at the furthest hydrant.
While actual operation is carried out with the help of electrically operated
hydrant pumps, Jockey pump will take care of hydraulic losses in the system
during normal operation and maintain minimum specified pressure in the
header. Diesel engine driven pump is provided back-up to electrical pumps in
accordance with regulations. Power supply to the firefighting pump panel is
from both city and emergency sources.
Fire hose cabinets (FHC) are to be placed strategically in accordance with
NFPA & MNDF. All floors shall be provided with separate wet riser connected to
the single headed fire hydrant landing valve with fire hose cabinet consisting
of first aid box, swinging hose reels.
1.3. Portable Fire Extinguishers
Portable fire extinguishers of water (Gas pressure) type of 9 liters capacity,
6KG DCP fire extinguisher (gas cartridge type) and 2kg stored pressure fire
extinguisher are to be provided as first aid fire extinguishing appliances.
Fire Blankets shall be conforming to BS EN 1869: 1997 or any other equable
International Standard. Fire Blankets must be extremely flexible and can be
draped easily. The slim pack of fire blanket must be Red or White. The Fire
Blankets is got to be approved by the MNDF fire and Rescue Service before
Installation. Special permission should be taken if it is different from above.
The appliances are to be distributed over the entire floor area in such a way so
that a person has to travel not more than 10 m to reach the nearest
appliance. These are to be placed or hanged on wall in a group on several
suitable places.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
The number of extinguishers shall be calculated in accordance with MNDF.
Classification of extinguishers is in accordance with the following table:
Suitable Type of
Sl. No. Class of Fire
Fire in ordinary combustibles
i. (wood, vegetable, fibres, rubber Gas Expelled Water Type
plastics, paper etc.
Chemical extinguishers of
Fires in flammable liquids, paints,
ii. carbon dioxide, dry powder
grease, solvents and the like
type and buckets.
Chemical extinguishers of
Fire in gaseous substances under
iii. carbon dioxide and dry
pressure including liquefied gases
Fires in reactive chemicals, active Special type of dry powder
metals and the like extinguishers
The Fire Extinguishers shall be approved by the MNDF fire and Rescue Service
before Installation. Special permission should be taken if it is different from
1.4. Salient Features in Fire Fighting System Design
Below grade areas or blind spaces is protected against flammable fuel/vapour
penetration through structural intervention or mechanically ventilated as per
the requirements stated in MNDF.
Fire hydrants are to be provided in building.
This section deals with the requirements of provision of firefighting services.
The pumps, prime movers & Control panels etc. is installed in the pump
Following is the broad scope of work:
• Fire Hydrant System
• Fire Extinguisher
• Pumps & prime movers
• Electrical panels etc.
1.6. Scope of Work
The broad scope of work is include Design, Procurement, Construction,
Completion, Testing and Commissioning of item as detailed below .
• The scope of work includes design, supply, Erection, coordination
among different trades, liaison/coordination with relevant local
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
government departments, Testing and Commissioning of Fire Protection
system for the proposed Residential building. The Fire Protection scope
covers internal work of the buildings.
• The building is provided with Fire Protection system, as required by the
MNDF requirement, relevant NFPA & local-building regulations
applicable for the project.
• Provision of underground Fire water tank and suitable rating fire
pumping system for the proposed buildings shall be as per MNDF
requirement. Solenoid valve with auto closing and opening, depending
on the tank water level is to be provided. Capacity of the Fire Water
Tank is to be designed as per MNDF.
• All the fire pumps except jockey pumps shall be UL listed and will be
supplied along with UL listed controllers having soft starters with inbuilt
pressures switches.
• Fire Water Pumps & Panel along with associated piping, valves and
accessories shall be as per system requirements. Electrical control panel
for Fire Pumps and cabling / wiring including connection to various FPS
• Fire Hydrant System with piping network, landing valves, Hose Reels,
Hose box and Hose Cabinets as per MNDF requirement.
• Internal Hydrants with associated piping and valves. Location of the
Hydrant Cabinets is coordinated with Architects, other services & must
comply with the applicable codes & standards.
• Portable Fire Extinguishers to fight fire at incipient stage. Fire
Extinguishers are to be provided as per travel distance and area
coverage throughout the building, as per the prevailing codes of MNDF.
• Sealing of cut-outs / openings with Fire sealants. The fire rating of the
sealant should be compatible with the structure (Floor/Wall), as the
• Interface with various other disciplines as per the Specifications. FPS
piping will not run inside the water sensitive areas like TC rooms,
Substations, Generators rooms etc.
• To develop Schematic Riser diagrams, detail working drawings showing
hydrant pipe network, fire hose stations network, pump room layout,
portable Fire Extinguisher locations etc. complete.
• Obtaining Completion Certificate from the Local Fire Officer.
• Provide fire and life safety signage.
• It is responsible for the Supply & Installation of all the above-mentioned
Fire Protection Systems in accordance with the Specifications as
mentioned above.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
1.7. General Specifications
• Pipes and Fittings Pipes for Wet Riser & dry riser system shall be of G.I
C class Pipe. Pipes up to 150mm dia are conforming to MNDF. Pipes
with dia. 200mm and above (6mm thick) is conforming to MNDF. All
pipes must be as per approved makes only (G.I. C-class).
Joint for black steel pipes and fittings shall be metal to metal thread joints. A
small amount of red lead may be used for lubrication and rust prevention.
Joints are not be welded or caulked.
Joints between G.I. pipes and fittings should be made with the pipes and
fittings having "V" groove and welded with electrical resistance welding in an
approved manner. Butt welded joints are not acceptable.
1.8. Pipe Protection
• All pipes in underground masonry trenches/service tunnels, above
ground and in exposed locations are to be painted with one coat of red
oxide primer before installation and two or more coats of synthetic
enamel paint of approved shade after installation.
• Pipes in wall chases are to be protected from corrosion by 2 coats of
bituminous paints.
• Protection of Underground Pipes:
Corrosion protection tape shall be wrapped on G.I. C class Pipes to be buried
in ground. This corrosion protection tape comprises of coal tar/asphalt
component supported on fabric of organic or inorganic fibre and minimum 4
mm. thick and conforming to requirement of MNDF – code of practice for
coating and wrapping of underground G.I. Pipe line. Before application of
corrosion protection tape all foreign matter on pipe are to be removed with
the help of wire brush and suitable primer shall be applied over the pipe
thereafter. The primer is allowed to dry until the solvent evaporates and the
surface becomes tacky. Both primer and tape shall be sourced from the same
manufacturer. Corrosion protection tape is then wound around the pipe in
spiral fashion and bounded completely to the pipe. There is no air pocket or
bubble beneath the tape. The overlaps are 25 mm and 250 mm is leave
uncoated on either end of pipe to permit installation. This area is wrapped in
accordance with the manufacturer’s recommendations. If applications are
done in cold weather, the surface of the pipe is pre-heated until it is warm to
touch and traces of moisture are removed and then primer is applying and
allowed to dry.
1.9. Installation of Pipes
All pipes must be adequately supported from ceiling or walls by structural
clamps fabricated from M.S. structural e.g. rods, channels, angles and flats.
All clamps are to be painted with one coat of primer and two coats of black
enamel paint. It is required to provide inserts at the time of slab casting or
provide suitable anchor fasteners.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
The pipe supports or hangers shall be designed to withstand combined weight
of pipe, pipes fittings, fluid in pipe and insulation. Pipe supports shall be of
steel and coated with rust preventing paint and finished with two coats black
enamel paint. The maximum spacing for pipes supports shall be as below:
Pipe (MM) Spacing (MTR) Size of support
150 & above 3.0 12mm
Pipes supports shall be spaced at maximum interval of 1.5 mtr. on either side
of heavy fitting and valves. Wherever piping passes through walls, pipes
sleeves of diameter larger than that of piping is to be provided. Pipe sleeves
are of steel or cast iron pipe.
The underground piping shall be supported with AAC Block masonry pedestal
blocks of suitable size and strength provided at an interval of 3.0 mtrs. The
pipes are laid at 1 mtr depth (top of the pipe) and trench excavated for
sufficient width. The rate for pipe is including the scope of excavation/refilling
the trench. 1:2:4 concrete thrust blocks are also to be provided at turning of
pipe. The cost of installation includes concrete pedestals etc. as required and
to be included in the item rate.
1.10. Internal Hydrants
• The Single headed Internal Hydrant outlet is as per MNDF
• A cap with chain shall be provided on the head of the outlet. The hydrant
shall have an instantaneous pattern female coupling for connecting to Hose
• The Landing Valve is of fitted to a Tee connection on the wet riser at the
• The Hydrant is constructed from gun metal and finished to a smooth polish
on screwed ends. The Hydrant is screwed inlet of 80mm dia. Flanged type
with 4 nos. holes. The Hydrant is a PVC plug with chain fixed to the main
body of the Hydrant. The Hydrant is not leak at any screwed joint.
1.11. First‐‐Aid Hose Reel Equipment
• Recess Hose reels approved to BS EN 671-1: 1995, or any other equable
International Standard, Automatic operation, Right or Left hand take off.
Including 30m length of Hose, 19mm diameter Hose approved to PR EN
694, or any other equable International Standard, and Nylon twist
operated Jet/spray Nozzle on mounting plate with integral flexi guide for
Hose withdrawal device. 03 or 04 fixing holes should be provided in
position indicated to suit M8/M10 sized fixing screws or M12 fixing bolts.
With Ball valve inlet and Flexible inlet water Pipe.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• The overall width of the reel is not more than 850mm. The overall height
of the Reel is less than 850mm including Hose and integral Flexi guide for
hose withdrawal guide. The overall depth of the Hose reel is not more than
150mm. Color of the Reel is Red, fitted with operating instruction plate.
• The Hose Reels and the related equipment’s must be approved by the
MNDF Fire and Rescue Service before Installation. Special permission is
taken for the other size of the Hose reels.
• The Hose Reels nozzle retainer or hose guide and the inlet valve is fitted at
a height of about 900mm above floor level.
• The hose reel cabinet shall be Recess mounting type with or without glass
paneled door for use with the above-mentioned sized Hose Reels. Hose
Reel Cabinet dimension should be no more than 900mm in width, 900mm
in height, 160mm in depth (including door).
• Color of the cabinet is Red. Special permission is taken for other Colour.
• Recessed Latch Type handle is installed. Hose reel signage is in accordance
to BS 5499 or any other equable International Standard. Fixing hole is
• The Hose Reel cabinets are to be approved by the MNDF fire and Rescue
Service before Installation.
1.12. Hose Pipes, Branch Pipes and Nozzles
Two numbers Hose Pipes Internal hydrants is rubber lined woven jacketed
(RRL) and 63mm in dia. 15m long, (non-percolating Reinforced rubber lined)
conforming to MNDF & NFPA. The hose is sufficiently flexible and capable of
being rolled. Length of hose pipe Min 15 m. Each run of hose is complete with
necessary Male & Female Gun Metal coupling at the ends to match with the
landing valve or with another run of hose pipe or with branch pipe. The
couplings is of instantaneous spring lock type. It is conforming to MNDF &
Branch Pipes
Standard short sized Branch pipe is constructed from alloy of Stainless-Steel
(SS-316) material 63 mm dia and be complete with male instantaneous
spring lock type coupling for connection to the hose pipe. The branch pipe is
externally threaded to receive the nozzle conforming to MNDF & NFPA
The Nozzle is of SS-316, 20mm internal diameter. The screw threads at the
inlet connection should match with the threading on the branch pipe. The inlet
end is a hexagonal head to facilitate screwing of the nozzle on to the branch
pipe with nozzle spanner. End couplings, Branch pipe, and Nozzles is confirm
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
1.13. Orifice Plate
The Pressure in a Fire Fighting system varies from point to point. The pressure
is maximum in the pump house and minimum at the furthest hydrant at TOP
level. To reduce pressure to operating pressure at every internal hydrant,
orifice plates are provided before connection of landing valve between the
flanges of landing valve and pipe flange.
1.14. Fire Brigade Inlet Connections
Fire Brigade Inlet connection is provided near the pump house as specified for
the following purposes: -
• Fire brigade inlet connection to DRY riser with the sluice valve & non-
• The locations of these fire brigade connections are suitably decided with
the approval of Engineer-in-charge and with a view that these are easily
accessible to the fire brigade, without any possible hindrance.
1.15. Valve Chambers
It is to provide suitable AAC Block Masonry Chamber in cement mortal 1:4 (1
cement: 4 coarse sand) on cement concrete foundations 150 mm thick in
1:5:10 mix (1 cement: 5 fine sands: 10 graded stone aggregate 40 mm
normal size) 12 mm thick plaster inside and outside finished with a floating
coat of neat cement inside with cast iron surface box approved by fire brigade
including excavation, back filling complete.
1.16. Fire Extinguishers
1.16.1 Portable Fire Extinguishers
Portable fire extinguishers is selected, installed, inspected and maintained in
accordance with guidelines stated in MNDF.
1.16.2 Water Type Extinguisher (Gas Pressure Type)
The Extinguisher medium is primarily water stored under normal pressure; the
discharge being affected by release of Carbon Dioxide Gas from a 120 gms
The capacity of Extinguisher, when filled upto the indicated level, shall be of 9
The skin thickness of the cylinder is fabricated from Mild Steel sheet, welded
as required, with dish and dome, being of same thickness, and of size not
exceeding the diameter of body. The diameter of body shall be not less than
150 mm and not exceeding 200 mm. The neck is externally threaded up to
minimum depth of 16 mm, and leaded tin bronze.
The cap is of leaded tin bronze, and screwed on the body up to a minimum of
1.6 cm depth, with parallel screw thread to match the neck ring. The siphon
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
tube shall be of brass or G.I and the strainer of brass. The cartridge holder,
knob, discharge fittings and plunger to be of Brass / Leaded tin bronze, and
plunger of stainless steel (approved grade), spring of stainless steel
(approved grade). It is a snifter valve to act as breather. The cap is with
handle fixed to it. The discharge hose is of braided nylon, of 10 mm dia and
600 mm long, with a nozzle of brass fitted at end.
The extinguisher is treated for anti-corrosion internally and externally, and
externally painted with Fire Red paint. The paint is stove enameled / powder
coated. The cartridge shall be as per MNDF, and have 60 gm. net carbon
dioxide gas for expelling. The extinguisher, body and cap is treated to an
internal hydraulic pressure of 25 kg/cm². It is external marking with letter A,
of 2.5 cm height, in TS - ELECT.- 493 block letters within a triangle of 5 cm
each side. The extinguisher is upright in operation, with the body placed on
ground, and discharge tube with nozzle held in one hand to give a throw of
not less than 6 meters, and continue so for at least 60 sec. The extinguisher
body is clearly marked with international standard.
1.16.3 Carbon Dioxide Extinguisher
The Carbon Dioxide Extinguisher is as per MNDF & NFPA
The Body is constructed of seamless tube conforming to MNDF & NFPA and
having a convex dome and flat base. Its dia is maximum 140 mm, and the
overlay height is not exceeding 720 mm.
The discharge mechanism is through a control valve conforming to MNDF &
NFPA. The internal siphon tube is of copper or aluminum conforming to
relevant specifications.
Hose pipe is high pressure braided Rubber hose with a minimum burst
pressure of 140 kg/cm², and is approximately 1.0 meters in length having
internal dia of 10 mm. The discharge horn is of high-quality unbreakable
plastic with gradually expanding shape, to convert liquid carbon dioxide into
gas form. The handgrip of Discharge horn is insulated with Rubber of
appropriate thickness.
The gas is conforming to MNDF and is stored at about 85 kg/cm². The
expansion ratio between stored liquid carbon dioxide to expanded gas is 1:9
times and total discharge time is minimum 10 sec. and Maximum 25 sec.
The extinguisher is fulfilling the following test pressures: a) Cylinder: 236
kg/cm² b) Control Valve: 125 kg/cm² c) Burst pressure of Hose: 140 kg/cm²
It is an upright type. The cylinder, including the control valve and high-
pressure Discharge Hose is comply with relevant Statutory Regulations, and
be approved by chief Controller of Explosives.
The Extinguisher including components is as per MNDF.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
1.17. Power and Control Panel and Other Control Components
This section covers the detailed requirements of the power and the control
panel for the wet riser system, and also for the various control components in
1.18. Power and Control Panel
1.18.1 Constructional Requirements
General Features
The power and control panel is totally enclosed, free standing floor mounted
cubicle type, fabricated out of sheet steel not less than 2mm thick. Wherever
necessary, additional stiffening is to be provided by Galvanized MS angle iron
framework. General construction is of compartmentalization and
sectionalisation such as mains incomers, electric fire pump, diesel fire pump,
pressurization pump, and control, so that there is no mix up of power and
control wiring and connections in the same sections as far as possible. The
panel is also have the space for cable allays. The space for cable alleys is at
least 200mm wide to the entire depth of panel. The panel is front operated
type with all connections accessible from the front. Front doors are hinged
type. Back doors are hinged type or removable type for inspection. The door
hinges is of concealed type. The doors for bus bar chamber are of removable
type with the help of bolts. The doors are provided with quick fixing doors
knobs with indication. The general arrangement of the panel is got approved
before fabrication the cubicle construction is as per MNDF.
1.18.2 Cable entries and gland plates
All cable entries are through gland plates which are removable and
sectionalized. Where heavy cables are brought in and terminated, suitable
clamps are incorporated to relieve the stress on the glands due to the weight
of the cable. Cable entries may be from top or bottom depending on the
equipment layout and cable scheme as approved.
1.18.3 Bus bar and Connections
The busbars is air insulated, and of aluminium of high conductivity electrolytic
quality and of adequate cross section. Current density is not exceeding 1.3
amps. per sq.cm. All connections to individual circuits from the busbars are
preferably with solid connections. The busbars and the connections are
covered with PVC sleeves or in an approved manner. Busbars are suitably
supported using non-hygroscopic insulated DMC/SMC supports. High tensile
bolts and spring washers are to be provided at bus bar joints.
1.18.4 Earthing Arrangement
GI strip 25mm x 5mm is run at the rear of the board. 2 nos. earth terminals
are to be provided at the ends of the GI strip for connection to earth system.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
1.18.5 Terminal Blocks and Small Wiring
Terminal blocks are of heavy duty type and generally not less than 15 amps
250V grade upto 100V, and 600V grade for the rest of the functions. They are
easily accessible for maintenance. All control wiring inside the panel is with
PVC insulated copper conductor FRLS of 2.5 sq.mm. size and 600V grade
conforming to as per MNDF. Suitable color-coding is adopted. Wiring harness
is neatly formed and run preferably function wise, and as far as possible
segregated voltage wise. Identification ferrules are used at both ends of the
1.18.6 Instruments and Lamps
All indication lamps and instruments shall be flush mounted type in front of
the panel. The voltmeter and ammeter size shall be 100mm nominal (dial
size) conforming to MNDF.
A necessary ammeter with selector switch is to be provided with suitable
Current Transformer.
Indicating lamps to indicate the availability of electric supply is to be provided
at the incoming section. Necessary indicating lamps for alarm indications and
battery charging are provided in the respective sections.
All indicating lamps and meter is protected with HRC cartridge type fuses. /2
Amp back up MCB.
All internal components shall be provided with suitable identification labels.
Suitably engraved labels are fixed at the panel for all switches, instrument
push buttons, indicating lamps etc.
1.19. Equipment Requirements
The power and control panel is to be comprising of individual section for the
various equipment’s of the system and controls, in a combined cubicle type
design. All switches, MCCBS, MCBS and fuse/fuse switch units is conforming
to relevant MNDF.
1.19.2 Incomer Section & outgoing section
Incomer section:
2 nos. Suitable amps 4 pole MCCB unit complete. One set of 96 mm square
digital Ammeter (0-200 Amps) completes with built in selector switch and
CTS. Two set of 96 mm square digital Voltmeter with built in selector switch
(0 - 500 V) complete with control fuses and selector switch. One set of phase
LED indicating lights with control MCB. One set of 4 strips of 300 Amps
aluminium busbars.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
Outgoing feeder
• One number of Suitable Amps TPN MCCB with built in thermal magnetic
release within built O/C ,S/C & EF safety (25 KA, Ics = Icu) unit
complete, S P Preventer, ML 4 type Contactor for soft starting, start and
stop push buttons, auto-manual switch, digital Ammeter with CTS, ASS,
LED phase indicating lights, Auxiliary Contactors for
interlocking/sequence of operation, control terminals complete in all
respect with interconnections for Hydrant Pump.
• One number of Suitable Amps rated TPN MCCB (10 KA, Ics = Icu)
unit- complete, ML 1.5 type Contactor for D O L starting with overload
relay, start and stop button, digital Ammeter, CTS and selector switch,
phase indicating lights, Auxiliary contacts for interlocking/sequence of
operation, control terminals complete in all respect for Jockey Pump.
Control Wiring from Pressure Switches of different settings in Hydrant and
Jockey Pumps, for sequence of operation is included to complete the system.
Color code with ferrule marking is also made.
The cabling is PVC insulated FRLS and aluminium / copper conductor cable of
1100 volts grade conforming to MNDF as required from Fire Pump Board to
motor and cable of suitable size as per BOQ.
1.19.3 Electric Fire Pump Section
This section is incorporating the following facilities.
• Suitable capacity MCCBS
• Control system components and equipment such as relays, contractors
and timers etc. for automatic operation.
• Starter Unit, Current Transformer and digital ammeter.
• LED Indication lamps, their fuses, terminal block, push buttons, control
and selector switches etc. are as required.
• Pump lock out devices due to faults or abnormalities as specified in
operating sequence.
• Visual/audio alarms, indications and communications facility as specified
in operating sequence.
• Necessary inter-connection and control wiring etc.
1.19.4 Engine Section
The engine section is incorporating the following facilities:
• Control system components and equipment such as relays, contractors,
timers etc. for automatic operation.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• Instruments, indicator lamps, MCB terminal blocks, push buttons, control
and selector switches etc. as are required.
• Engine shut down and block out devices due to faults or abnormalities as
• Visual/audio alarms and indications as specified.
• Inter-connection and control wiring etc.
1.19.5 Auxiliary Pump Section
The auxiliary pump section for jockey pump is incorporating the following:
• Control system components such as relays, times, contractors, etc. as
are necessary for functional requirements.
• Starter unit, current transformer and ammeter.
• Indication lamps, fuses, terminal blocks, push buttons selector, switch
etc. as required.
• Inter-connections and control wirings etc.
1.19.6 Control Section
This section is incorporated the following: -
• Control components integrating the various sections, so as to satisfy the
functional requirements.
• Battery charger unit with boost/float/Trickle charger facility with
voltmeter, capable of independently charging 2 sets of batteries at a
• Visual/audio alarms covered all alarm, trip indication.
• Lamps healthy test facility.
• Instruments, indicating lamps, push buttons, fuse terminal blocks etc. as
• Test facility to simulate operation of hydrants.
1.20. Other Control Components
1.20.1 Pressure Switches
Pressure switches is to be provided for switching on and off the pressurization
pump at pre-set pressures and also for switching off the fire pump at pre-set
pressure. Being the main component for initiating the signal for the operation
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
of the pumps, the pressure settings is totally reliable, sturdy in construction
and of long life. The pressure settings should be adjustable.
1.20.2 Power Supply for Controls
In order to ensure that the control systems remain co-operational at all times
the control system is designed for 24 VDC operation fed from the battery.
This is independent of the starting battery for the engine i.e. battery is remain
trickle charged at all times from the separate battery charger at the control
2. Electrical Work and Earthing
This section covers the detailed requirements of electrical works including
earthing, for the materials installation.
Electric power supply shall be terminated in the incoming switch gear of the
power and control panel by the Department. All further connections to the
various components of the system is the responsibility of the Contractor, for a
complete and working system, satisfying all the functional requirements.
The scope is particularly including the following:
Power and Control Panel(s) as given in relevant section.
All inter-connections with multi-core armoured copper cables of size suitable
between various control units and control panel(s). All power cable
connections with multi-core armoured aluminium cables of size as specified in
the approved drawings, between panels, motors etc.
Necessary earthing with 2 Nos. G.I. plate electrodes and loop earthing.
2.2. Fire Protection System - Pipe Work
General Requirements
Pipes are fixed in a manner as to provide easy accessibility for repair and
maintenance and not cause obstruction in shafts, passages etc.
Valves and other appurtenances are so located that they are easily accessible
for operations, repairs and maintenance.
Pipe accessories such as gauges, meters, control devices, etc. have the same
working pressure rating as the associated pipework. All pipework is free from
burrs, rust and scale and cleaned before installation. All personnel engaged on
welding operations must possess a certificate of competence issued by an
acceptable / recognized authority.
Pipes of following types are to be used:
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
G.I black pipes in accordance with MNDF heavy grade (for pipes of sizes 150
mm N.B. and below) suitably lagged on the outside to prevent soil corrosion.
G.I. pipes buried below ground are also to be suitably be lagged with 2 layers
of 400-micron polythene sheet over 2 coats of bitumen.
Steel pipelines up to 150 mm diameter shall be in accordance with MNDF,
Part-II (heavy grade) while pipelines above 150 mm diameter shall be in
accordance with MNDF.
All pipe clamps and supports are fabricated from MS steel sections and shall
be factory galvanized before use at Site.
Pipes are hung by means of expandable anchor fastener of approved make
and design. The hangers and clamps are fastened by means of galvanized
nuts and bolts. The size/diameter of the anchor fastener and the clamps are
suitable to carry the weight of water filled pipe and dead load normally
Hangers and supports are thoroughly galvanized after fabrication. The
selection and design of the hanger and support must be capable of carrying
the sum of all concurrently acting loads. They should be designed to provide
the required supporting effects and allow pipeline movements as necessary.
All guides, anchor braces, dampener, expansion joint and structural steel to
be attached to the building/structure trenches etc. are provided.
The piping system are to be tested for leakages at 2 times the operating
pressure or 1.5 time shut-off pressure, whichever is highest including testing
for water hammer effects.
Flanged joints are used for connections for vessels, equipment, flanged valves
and also on two straight lengths of pipelines of strategic points to facilitate
erection and subsequent maintenance work.
For pipes underground installation the pipes are to be buried at least one
meter below ground level and have 230 mm x 230 mm masonry or concrete
supports at least 300 mm high at 3m intervals. Masonry work to have plain
cement concrete foundation (1 cement: 4 coarse sand: 8 stone aggregate) of
size 380x380x75 thick resting on firm soil.
Mains below ground level are supported at regular intervals not exceeding 3.0
metre and laid at least 2.0 metre away from the building.
Piping Installation and Support
Pipe work and fittings are supported by hangers or brackets so as to permit
free expansion and contraction. Risers are to be supported at each floor with
galvanized steel clamps. To permit free movement of common piping support
are from a common hanger bar fabricated from galvanized steel sections.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
Pipe hangers are provided at the following maximum spacing:
Pipe Dia (mm) Hanger Rod Dia Spacing between Supports
The end of the steel rods are threaded and not welded to the threaded bolt.
Pipe sleeves, larger diameter than pipes, are provided wherever pipes pass
through walls and slab and annular space filled with fiberglass and finished
with retainer rings.
Automatic air valves are provided at all high points in the piping system for
venting. All valves are of 15mm pipe size and are associated with an equal
size gate valve.
Discharge from the air valves are piped through a pipe to the nearest drain or
sump. All pipes are pitched towards drain points.
2.3. Air Vessel
The air vessel are provided to compensate for slight loss of pressure in the
system and to provide an air cushion for counter-acting pressure, surges,
whenever the pumping sets come into operation. Air vessel is conform to
MNDF. It is normally half full of water, when the system is in normal
operation. Air vessel is fabricated with 8 mm thick M.S. plate with dished ends
and suitable supporting legs. It is provided with one 100 mm diameter flanged
connection from pump, one 25 mm drain with valve, one water level gauge
and 25 mm sockets for pressure switches. The air vessel is tested to pressure
for 12 hours at 2 times the operating pressure or 1.5 times the shut-off.
2.4.1 Sluice Valves
Sluice valves are double flanged valves with cast iron body. The spindle, wall
seat and wedge nuts are of bronze. They are generally having non-rising
Sluice valves are conforming to MNDF.
2.4.2 Butterfly Valve
The butterfly valve is suitable for waterworks and rated for 300 P.S.I
The body is of cast iron conforming to MNDF in circular shape and of high
strength to take the water pressure. The disc is heavy duty cast iron with anti-
corrosive epoxy or nickel coating.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
The valve seat is of high-grade elastomer or nitrile rubber. The valve in closed
position has complete contact between the seat and the disc throughout the
perimeter. The elastomer rubber has a long life and not give away on
continuous applied water pressure. The shaft is EN 8 grade carbon steel.
The valve is to be fitted between two flanges on either side of pipe flanges.
The valve edge rubber is projected outside such that they are wedged within
the pipe flanges to prevent leakages.
2.4.3 Ball Valve
The ball valve is made of forged brass and suitable for test pressure of pipe
line. The valve is internally threaded to receive pipe connections.
The ball is made from brass and machined to perfect round shape and
subsequently chrome plated. The seat of the valve body-bonnet gasket and
gland packing is of Teflon.
The handle is provided with PVC jacket. The handle also indicates the direction
of ‘open’ and ‘closed’ situations. The gap between the ball and the Teflon
packing is sealed to prevent water seeping.
The handle also be provided with a lug to keep the movement of the ball valve
within 90°. The lever is operated smoothly and without application of any
unnecessary force.
2.4.4 Gun Metal Valves
Gun metal Valves are used for smaller diameter pipes, and for threaded
connections. The Valves are bear certification in accordance with MNDF.
The body and bonnet are of gun metal conforming to MNDF. The stem gland
and gland nut are of forged brass conforming to MNDF. The hand wheel is of
cast iron conforming to MNDF.
The hand wheel is of high-quality finish to avoid hand abrasions. Movement is
also be easy. The spindle is non-rising type.
2.4.5 Non-Return Valve
Non-return valves are cast iron double flanged with cast iron body and
gunmetal internal parts conforming to MNDF.
2.5. Pressure Switch
The pressure switches are employed for starting and shutting down operation
of pumps automatically, dictated by line pressure. The pressure switch is
diaphragm type. The housing is die cast aluminium, with SS 316 movement,
pressure element and socket. The set pressure is adjustable.
The Switch is suitable for consistent and repeated operations without change
in values. It is provided with IP: 55 water and environment protection.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
2.6. Pressure Gauge
Pressure gauge is provided near all individual connections of the hydrant
system with isolation valves and near each flow switch assembly of the
sprinkler system. Pressure gauge is 50 mm dia gunmetal bourdon type with
gunmetal isolation ball valve, tapping and connecting pipe and nipple. The
gauge is installed at appropriate height for easy readability.
All hydrant pipes shall be painted with post office red color paint. All G.I. pipes
are first be cleaned thoroughly before application of primer coat. After
application of primer coat two coats of enamel paint is to be applied. Nuts and
bolts are painted black, while valves are painted blue.
2.8. Fire Hydrants
2.8.1 Internal Hydrants
• Each internal fire hydrant station is consisting of two numbers of 63 mm
dia. 15 m long rubberized fabric lined hose pipes with gunmetal male and
female instantaneous type coupling machine wound with GI wire, fire hose
reel, gunmetal branch pipe with nozzle as per MNDF requirement.
• Standard fire hose reels of 19mm diameter high pressure Dunlop rubber
hose 30 m long with gunmetal nozzle, all mounted on a circular hose reel
of heavy duty mild steel construction having cast iron brackets are also to
be provided. Hose reel is connected directly to the wet riser with an
isolating valve. Hose reel is conforming to MNDF and is mounted vertically.
• Each internal hydrant hose cabinet is to be provided with a drain in the
bottom plate. The drain point leads away to the nearest general drain.
• Each internal hydrant hose cabinet is also be provided with a nozzle
spanner and a fireman’s axe.
• Each hose cabinet is conspicuously painted with the letters “FIRE HOSE”.
2.9. Hose Reel
Recess Hose reels approved to BS EN 671-1: 1995, or any other equable
International Standard, Automatic operation, Right or Left hand take off.
Including 30m length of Hose, 19mm diameter Hose approved to PR EN 694,
or any other equable International Standard, and Nylon twist operated
Jet/spray Nozzle on mounting plate with integral flexi guide for Hose
withdrawal device. 03 or 04 fixing holes shall be provided in position indicated
to suit M8/M10 sized fixing screws or M12 fixing bolts. With Ball valve inlet
and Flexible inlet water Pipe.
The Hose Reels and the related equipment’s are to be approved by the MNDF
Fire and Rescue Service before Installation. Special permission is to be taken
for the other size of the Hose reels.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
The Hose Reels nozzle retainer or hose guide and the inlet valve should be
fitted at a height of about 900mm above floor level.
2.10. Fire Hose
All hose pipes are of 63 mm diameter RRL/ CP as required, conforming to
MNDF. The hose is provided with copper alloy delivery coupling. The hose is
capable of withstanding a bursting pressure of 35.7 Kg/Sq.cm without undue
leakage or sweating. Hose is provided with instantaneous spring-lock, type
2.11. Branch Pipe, Nozzle
Branch pipes are of gun metal with loaded tin bronze ring at the discharge and
to receive the nozzle and provided at the other with a leaded tin bronze ring
to fit into the instantaneous coupling. Nozzle is of spray type of diameter of
not less than 16 mm and not more than 25 mm. Nozzle is of loaded tin bronze
branch pipe and nozzle is of instantaneous pattern conforming to MNDF.
2.12. Hose Cabinet
Hose cabinet is provided for all internal and external fire hydrants. Hose
cabinets are fabricated from 16 gauge MS powder coated sheet of fully welded
construction with hinged double front door partially glazed (3 mm glass panel)
with locking arrangement, stove enameled fire red paint (shade No. 536 of
IS:5) with “FIRE HOSE” written on it prominently. Cabinet surfaces in contact
with the walls are not be powder coated but instead given two coats of anti-
corrosive bit mastic paint.
2.13. Internal Hose Cabinet
Hose cabinet is of glass fronted with hinged door and lock. The cabinet is
made of 16-gauge thick MS sheet and spray painted to shade No. 536 of IS:5.
The hose cabinet is of size to accommodate the following:
• Landing valves (Single headed)
• Hose reel (30 mtr.)
• Branch pipes, nozzles (2 sets)
• Fire man's axe and hand appliances
2.14 Fire Protection System
• Check all hydrant valves by opening and closing: any valve found to be
open is to be closed.
• Check all the piping under hydro test.
• Check that all suction and delivery connections are properly made for
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale, Republic of
Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• Check rotation of each motor after decoupling and correct the same if
• Test run each pump set.
• All pump sets shall run continuously for 8 hours (if required with
temporary piping back to the tank).
• Pressurize the fire hydrant system by running the jockey pump and
after it attains the shutoff pressure of the pump, then
• Open bypass valve and allow the pressure to drop in the system. Check
that the jockey pump cuts-in and cuts-out at the preset pressure. If
necessary, adjust the pressure switch for the jockey pump. Close by-
• Open hydrant valve and allow the water to below into the fire water
tank in order to avoid wastage of water. The main fire pump is cut-in at
the preset pressure and is not cutout automatically on reaching the
normal line pressure. The main fire pump is stop only by manual push
button. However, the jockey pump is cut-out as soon as the main pump
• Switch off the main fire pump and test check the diesel engine driven
pump in the same manner as the electrically driven pump,
• When the fire pumps have been checked for satisfactory working on
automatic controls, open fire hydrant valves simultaneously and allow
the hose pipes to discharge water into the fire tank to avoid wastage.
• Check each landing valve, male and female couplings and branch pipes,
for compatibility with each other. Each landing valve is also be checked
by opening and closing under pressure.
• Check all annunciations by simulating the alarm conditions at site.
• Start the sprinkler pump and develop the required pressure in the
sprinkler pipes.
• Open the test valve to test the automatic starting of the pump. If
necessary, make necessary adjustments in the setting of pressure
switch. The sprinkler water gong
• alarm is also operate when the test valve is open. This operation is to
be done for each and every section of the sprinkler system and the
alarm for each section (via flow switch) is checked for operation.
• After satisfactory operation of the pump the Tenderer is set up mock
fire and test the system.
• Check all annunciations by simulating the alarm conditions at site.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
TECHNICAL SPECIFICATIONS
ELECTRICAL SYSTEM
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
1. Scope of Work of the Electrical Works
The Scope of work includes supply, installation, testing, commissioning
and handing over the entire electrical system, As-Built drawings and O &
M manuals along with necessary test certificates as required.
The works involves as follows –
(a) Internal Electrical Installation with switch, sockets & wiring etc. The
Lighting fixtures and fans will be provided as follows :
i) Housing Units - Lighting Fixtures and Ceiling
ii) Common areas, services - Lighting Fixtures, Ceiling Fans,
areas i.e. Electrical Exhaust Fans
Rooms, Pump Rooms etc.
(b) The Exit Lights to be provided as per the codal and local by-laws
requirements applicable.
(c) No Exhaust Fans, Bell buzzer, Geyser, TV and Telephone
instruments, ONT etc. to be provided inside the flats.
(d) Distribution Boards
(e) Elevators (3 nos. per tower as per specifications)
(f) Fire Detection & Alarm System (Conventional type-Manual)
(g) Lightning Protection System (Conventional type)
(h) Main Distribution Board of Tower with incoming cables from Sub
Station, laying and termination at both ends.
(i) Meter Boards Enclosures with Meters as approved by Local
Statutory body i.e. M/s STELCO
(j) Common area Panel for Lighting and Power Panel for Residential
with incoming cables and termination at both ends
(k) Common area Panel for Lighting and Power Panel for Commercial
with incoming cables and termination at both ends
(l) Lift panels with incoming cable and outgoing cables with
terminations at both ends
(m) Fire Fighting Panel with incoming cable and outgoing cables with
terminations at both ends.
(n) Incoming cable with terminations at both ends for Plumbing Panel
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
(o) Earthing System
(p) LT Cables & Cable Tray
(q) Safety Equipment.
(r) Conduiting for ELV systems such as CCTV, GPON System , Access
Control System, data / voice networking, antennas etc.
(s) Obtaining necessary statutory approvals from concern authorities
i.e. electricity authorities etc.
(t) 415V, 3 Phase, 4 wires, 50 Hz Incoming supply will be received in
the Main Distribution Board of the Tower placed in the panel room
at Ground Floor.
(u) The Meter Boards (approx. 8 nos. per tower each suitable for
accommodating approx. 20 nos. meters) are provided with lockable
cubicle for individual separate meter of each Dwelling unit.
(v) The single point Electrical Supply to the Main Distribution Board of
the each Tower will be taken from the Sub Station, further all
distribution will be done inside the tower.
(w) The connections from the meter boards to the Flat distribution
Boards and Common area Panel to the common area light & power
DBs i.e. staircase DBs ,corridors & lift lobby area light & power DBs
will be done through sub main wiring in conduit. The conduits from
the panels to the shafts to be laid on the cable tray and in the
shafts on the cable tray /MS supports as per approved design.
(x) In the common areas DBs to be provided
(y) On the floors the concealed conduit from shafts to the distribution
Boards inside the Dwelling unit to be used
(z) To all Dwelling units 1-ph, 2W, 220V, 50HZ Electrical supply to be
provided. SPN Lighting + Power DB will be provided in the each flat.
(aa) Only 13A universal and 15A, 3-Pin round sockets to be used.
(bb) The circuits for Lights & Fans, 13A Sockets and 15A Sockets will be
(cc) The Sizes of the wires shall as follows –
(i) Lights, Fans and call bell : 2x1.5 + 1x1.5 Sqmm Cu
(ii) 13A Universal sockets : 2x2.5 + 1x2.5 Sqmm Cu
(iii) 15A Sockets : 2x4.0 + 1x4.0 Sqmm Cu
(dd) The maximum points which can be connected in a circuits –
(i) Lights, Fans and call bell : Five (5) Nos.
(ii) 13A Universal sockets : Two (2) Nos.
(iii) 15A Sockets : Two (2) Nos.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
(ee) The sub main sizes as follows:
(i) 2 BHK : 2x16.0 + 1x6.0 Sqmm Cu
(ff) Emergency Lights for all common areas, service rooms and escape
routes to be provided.
(gg) Self-contained Exit Sign with standby batteries and automatic
charging facility to be provided.
(hh) Codes and Standards to be Followed –
(i) State Electric Company Ltd (STELCO) – Energy and Power
(ii) Maldives Energy Authority (MEA)
(iii) Relevant Telecom and Internet Service Provider
(iv) Maldives National Defence Force (MNDF) – Fire Protection
(v) Ministry of Environment & Energy (if relevant)
(vi) Ministry of Health (if relevant)
(vii) International Codes & Standards
(viii) National Fire Protection Association (NFPA)
2. Internal Electrification
2.1 Electrical Wiring
2.1.1 Electrical wiring should be done by a MEA approved and
licensed electrician.
• Wiring color code:
o In single phase wiring, the phase wire must be brown, neutral must
be blue, and the earth must be green with yellow stripes.
o In three phase wiring, phase 1 must be black, phase 2 must be
brown, phase 3 must be grey, neutral must be blue, and the earth
must be green with yellow stripes.
o In any case, for earth wire anything other than green with yellow
stripes and for neutral anything other than blue must not be used
o As a temporary measure, for as long as the MEA authorizes it, at
sites where three phase wiring is required, and the prescribed color
of wire is not available, the end of each wire should be sleeved with
the respective phase color.
• In three-phase wiring the load should be balanced among the three
• Phase wires are dimensioned to withstand in normal operation the
aggregated current of the loads there connected. The licensed
engineer or electrician (whereas applicable) certifies dimensions of
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• The typical tripping current for earth leakage circuit breaker in
households or residential buildings are 30 milli Amps. Nevertheless,
it is possible to set the tripping point to different current levels where
deemed necessary. The circuit breaker is 240 V rated voltage and
30-63 Amps rated current, 2 pole current operated ELCB. In case of
three phase circuits, for a tripping current of 30 milli Amps, the
circuit breaker is 30-63 A rated current, 380-400 rated voltage and 4
pole current operated. The rated current did not exceed the
prescribed level and the tripping current must not exceed 30 milli
Amps. ELCB with tripping currents less than 30mA can be accepted
where it is deemed necessary. Exception to this rule are ELCB of
residual current devices installed in central alternative current
systems of buildings which may have trigger current higher than 30
milli Amps but in any case not exceeding 100 milli Amps.
• For a light circuit, if the wire size is 1.5 mm2 a single circuit must not
exceed a total of 1000W.
• Not more than one phase must be used in a single box
• Wiring must be done in a conduit or trunking.
• Machineries installed in commercial and industrial electrical
installations must be connected by using appropriate cable size and
through starter or main switch. Such starter switch must be installed
close to the machinery in an easy to operate manner.
• Water prone areas should have water proof switches and socket
outlets. if normal switches & sockets are is used, it must be mounted
where water will not reach it.
• Any type of socket can be installed but at least one socket per room
is of Type G BS-1363.
• Insulation resistance of an installation (phase-neutral, phase-earth
and neutral-earth) should have minimum of 1 mega ohms.
• In case a resident needs to connect a backup/emergency generator
apart from the existing service provider’s supply a change-over
switch must be introduced. The change-over switch must be able to
disconnect the phase/live conductors and as well as the neutral, and
must present a rating adequate to the required load.
• All new electrical installations are tested and approved by either
licensed engineers or electricians (according to the case) for such
purposes, before being energized and will be accountable if any fault
arises from the distribution board wiring.
2.1.2 Selection and erection in relation to external influences
• The wiring system is selected and erected so as to be suitable for the
highest local ambient temperature.
• Wiring system components including cables and wiring accessories
are installed or handled only at temperature within the limits
stated in the relevant product specification or as given by the
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• In order to avoid the effects of heat from external sources one of the
following methods or an equally method is used to protect wiring
o Placing sufficiently far from the sources of heat;
o Selecting a system with due regard for the additional
temperature rise which may occur; or
o Local reinforcement or substitution of insulating material.
• The wiring system is selected and erected so that no damage is
caused by ingress of water. The completed wiring system complies
with the IP degree of protection relevant to the particular location.
• Where water may collect or condensation may form in wiring system,
provision is made for its escape.
• Where wiring system may be subjected to waves, protection against
mechanical damage is afforded.
• Wiring system is selected and erected so as to minimize the danger
arising from the ingress of solid foreign bodies. The completed wiring
system complies with the IP degree of protection relevant to the
particular location.
• In a location where dust in significant quantity is present, additional
precaution is taken to prevent the accumulation of dust or other
substances in quantities which could adversely affect the heat
dissipation from the wiring system.
• Where the presence of corrosive or pollution substances, including
water, is likely to give rise to corrosion or deterioration, parts of the
wiring system likely to be affected is suitably protected or
manufactured form a material resistant to such substances.
• Dissimilar metals liable to initiate electrolytic action are not placed in
contact with each other, unless special arrangements are made to
avoid the consequences of such contacts.
• Material liable to cause mutual or individual deterioration or
hazardous degradation is not placed in contact with each other.
• The wiring system is selected and erected so as to minimize the
damage arising from mechanical stress, e.g. by impact, penetration
or compression.
• In installations fixed to a structure or equipment, fixation is afforded
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
o The mechanical characteristics of the wiring system; or
o The location selected; or
o The provision of additional local or general mechanical protection;
o By any combination of the above.
• The wiring system supported by or fixed to structure of equipment
subject to vibration of medium severity or high severity is suitable for
such conditions, particularly where cables and cable connection are
• The wiring system is selected and erected so as to prevent during
installation, use or maintenance, damage to sheath and insulation of
cables and conductor and their terminations.
• When buried in the structure, conduits or cable ducting system is
completely erected for each circuit before any insulated conductor or
cable is drawn in.
• The radius of every bend in a wiring system complies with the
minimum bending radius recommended by the cable or wire
• Where the conductors and cables are not supported continuously by
their supports or due to the method of the installation, they are
supported by suitable means at appropriate intervals in such a
manner that the conductors and cables do not suffer damage by their
• Where a permanent tensile stress is applied to the wiring system
(e.g. by its own weight in vertical runs) a suitable type of cable or
conductor with appropriate cross- sectional areas and method of
mounting is selected, in such a manner that the conductors and
cables do not suffer damage by their own weight.
• Wiring system intended for the drawing in or out of conductors or
cables has adequate means of access to allow this operation.
• Wiring system buried in floors are sufficiently protected to prevent
damage caused by the intended use of the floor.
• Wiring system which are rigidly fixed and buried in the walls are run
horizontally or vertically or parallel to the room edges.
• Wiring system is installed so that excessive tensile stress to the
conductors and connections is avoided.
• Flexible wiring system is installed so that excessive tensile
stress to the conductors and connection is avoided.
• Where the conditions experienced or expected constitute a hazard
the wiring system is selected accordingly or special protective
measures are adopted.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• Where significant solar radiation is experienced or expected, a wiring
system suitable for the conditions are selected and erected or
adequate shielding is provided.
• The wiring system is selected and erected with due regard to the
seismic hazards of the location of the installation.
• Where the seismic hazards experienced are of low severity or higher,
particular attention is to be paid to the following:
o The fixing of wiring system to the building structure; and
o The connections between the fixed wiring and all items of
essential equipment, e.g. safety services, are selected for their
flexible quality.
• Where the risk due to structural movement exists, the cable support
and protection system employed is capable of permitting relative
movement so that conductors and cables are not subjects to
excessive mechanical stress.
• For flexible or unstable structures, flexible wiring system is used.
2.1.3 Electrical connections
• Connections between conductors and between conductors and other
equipment provide durable electrical continuity and adequate
mechanical strength and protection.
• The selection of the means of connection takes account as
appropriate of:
o The material of the conductor and its insulation;
o The number and shape of the wires forming the conductor;
o The cross-sectional area of the conductor; and
o The number of conductors to be connected together.
• All connections are accessible for inspection, testing and
maintenance, except for the following:
o Joints in buried cables;
o Compound-filled or encapsulated joints;
o Connections between a cold tail and the heating element as in
ceiling heating, floor heating and trace heating system.
• Wherever necessary, precautions are to be taken so that the
temperature attained by connections in normal service is not
impairing the effectiveness of the insulation of conductors connected
to them or supporting them.
2.1.4 Selection and erection to minimize the spread of fire
• The wiring system is installed so that the general building structural
performance and fire safety are not reduced.
• Where a wiring system passes through elements of building
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
construction such as floors, walls, roofs, ceilings, partitions or cavity
barriers, the opening remaining after passage of the wiring system is
sealed according to the degree of fire resistance (if any) prescribed
for the respective element of building construction before
• Wiring systems such as conduits, cable ducting, cable trunking,
busbars or busbar trunking system which penetrate elements of
building construction having specified fire resistance is internally
selected to the degree of fire resistance of the respective element
before penetration as well as being externally sealed as required by
Point 4.2 of this Article.
• No wiring system penetrates an element of building construction
which is intended to be load bearing unless the integrity of the load
bearing element can be assured after such penetration.
• Sealing arrangements should resist external influences to the same
degree as the wiring system with which they are used and in addition
they are of the following requirements:
o They are resistant to the products of combustion to the same
extent as the elements of building construction which have been
o They provide the same degree of protection from water
penetration as that is required for the building construction
element in which they have been installed;
o The seal and the wiring system shall be protected from dripping
water which may travel along the wiring system or which may
otherwise collect around the seal unless the materials used in the
seal are all resistant to moisture when finally assembled for use.
• During erection of a wiring system temporary arrangements may be
• During alteration work, sealing should be reinstated as quickly as
• The sealing arrangements are inspected to verify that they
conform to the erection instruction associated with the Integrated
Circuit Type Test for the product concerned.
• Band I and Band II voltage circuits, as per IEC 60449, is not
contained in the same wiring system unless every cable is insulated
for the highest voltage present or one of the following methods is
o Each conductor of a multi-core cable is insulated for the highest
voltage present in the cable; or
o The cables are insulated for their system voltage and
installed in separate compartment of a cable ducting or cable
trunking system; or
o A separate conduit system is employed.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• Wiring systems are not installed in the vicinity of service which
produce heat, smoke or fumes likely to be detrimental to the wiring,
unless it is protected from harmful effects by shielding arranged so
as not to affect the dissipation of heat from the wiring.
• Where a wiring system is routed below services liable to cause
condensation (such as water, steam or gas services), precautions are
to be taken to protect the wiring system from deleterious effects).
• Where electrical services are to be installed in proximity to non-
electrical services they are so arranged that any foreseeable
operation carried out on the other services will not cause damage to
the electrical services or the converse.
2.1.5 Selection and erection in relation to maintainability, including
• The knowledge and experience of the person or persons likely to
carry out the maintenance is to be taken into account in the selection
and erection of the wiring system.
• Wherever it is necessary to remove any protective measure in
order to carry out maintenance, provision is to be made so that
the protective measure can be reinstated without reduction of the
degree of protection originally intended.
• Provision is made for safe and adequate access to all parts of the
wiring system which may require maintenance.
2.2 Insulation, switching and control devices
2.2.1 Every Electrical Installation for residential use at LV is equipped
• A Power Control Switch (PCS):
o Capable and configured to disconnect the Electrical Installation
main supply in case the power demanded is higher than the
power contracted (and for which the PCS is configured).
o The PCS shall be installed at the distribution board serving the
Electrical Installation.
• A main switch circuit breaker is selected to be able to cut the
aggregated current of the group of Electrical Installation supplied
from it in case of short-circuit, and in any case at least 4.5k A.
• A residual current protective device:
o Residual current devices in direct current system are specially
designed for detection of direct current residual currents, and to
break circuit currents under normal conditions and fault
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
o Residual current protective devices ensures the disconnection
of all live conductors in the circuit protected.
o No protective conductor passes through the magnetic circuit of a
residual current protective device.
o Residual current protective devices are so selected, and the
electrical circuits so subdivided, that any earth-leakage current
which may be expected to occur during normal operation of
the connected lead(s) will be unlikely to cause unnecessary
tripping of the device.
o The use of a residual current protective device associated with
circuit not having a protective conductor, even if the rated
operating residual current does not exceed 30 mA, is not
considered as a measure sufficient for protection against indirect
o The use of residual current protective devices with an
auxiliary source not operating automatically in the case of
failure of the auxiliary source is permitted only if one of two
following conditions is fulfilled:
Protection against indirect contact is ensured even in the
case of failure of the auxiliary supply;
The devices shall be installed, operated, tested and
inspected by instructed person or skilled persons.
2.3 Earthing arrangements and protective conductors
• The performance of the earthing arrangements is adapted to the
safety and functional requirements of the Electrical Installation.
• The selection and erection of the equipment of the earthing
arrangements are such that:
o The value of earthing resistance is in accordance with protective
and functional requirements of the installation and expected to
be continuously effective;
o Earth-fault currents and earth-leakage currents can be
carried without danger, particularly from thermal, thermo-
mechanical and electro-mechanical stresses; and
o It is adequately robust or against or has additional mechanical
protection appropriate to the assessed condition of external
• Precautions are to be taken against the risk of damage to other
metallic parts through electrolysis
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• Earth electrodes for earthing Electrical Installations
o The following types of earth electrodes may be used:
Earth rods or pipes;
Earth tapes or wires;
Earth plates;
Earth electrodes embedded in foundation;
Metallic reinforcement of concrete
Metallic water-pipe system
Other suitable underground structures
o The type and embedded depth of earth electrodes should be such
that soil drying and freezing will not increase the earth resistance
of the earth electrodes above the required value.
o The materials used and the construction of the earth electrodes
should be such as to withstand mechanical damage due to
o The design of the earthing arrangements takes into account of
possible increase in earth resistance of earth electrodes due to
o Metallic water-pipe system may be used as earth electrodes
provided that the consent of the distributor of the water is
obtained and that suitable arrangements exist for the user of the
Electrical Installation to be warned of any proposed changes in
the water- pipe system.
o Metallic pipe system of service other than that mentioned as this
concerns only the water service, (e.g. for flammable liquids or
gases, heating system, etc.) is not used as earth electrodes for
protective purposes.
o Lead sheaths and other metallic covering of cables not liable to
deterioration through excessive corrosion may be used as earth
electrodes provided the consent of the owner of the cables is
obtained and suitable arrangements exist for the user of the
Electrical Installation to be warned of any proposed changes to
the cable that may affect its suitability as an earth electrode.
• The connection of an earthing system to an earth electrode is to be
soundly made and electrically satisfactory. Where a clamp is used, it
should not damage the electrode (e.g. a pipe) of the earthing
• In every installation, a main earthing terminal or bar is provided and
the following conductors are connected to it:
o Earthing conductors;
o Protective conductors;
o Main equipotential bonding conductors; and
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
o Functional earthing conductors, if required.
• Means are provided in an accessible position for disconnecting the
earthing conductor. Such means may conveniently be combined with
the main earthing terminal or bar, to permit measurement of the
resistance of the earthing arrangements. These joints are
disconnectable only by means of a tool, are mechanically strong, and
ensure the maintenance of electrical continuity.
• The cross-sectional area of every protective conductor which does
not form part of the supply or cable enclosure is, in any case, not
o 2.5 mm2 if mechanical protection is provided; or
o 4 mm2 if mechanical protection is not provided.
• Protective conductors shall comprise:
o Conductors in multi-core cables;
o Insulated or bare conductors in a common enclosure with live
o Fixed bare or insulate conductors;
o Metal covering, for example, the sheaths, screens and armouring
of certain cables;
o Metal conduits or other metal enclosures for conductors; and
o Certain extraneous conductive parts.
• Protective conductors should be suitably protected against
mechanical and chemical deterioration and electrodynamics forces.
• Joints of protective conductors are accessible for inspection and
testing except in compound-filled or encapsulated joints.
• No switching devices are inserted in the protective conductors,
but joints can be disconnected for test purposes by use of a tool.
• Where monitoring of earth-continuity is used, the operating coils are
not inserted in protective conductors.
• Wherever overcurrent protective devices are used for protection
against Electric Shock, the incorporation of the protective conductor
in the same wiring system as the live conductors or in their
immediate proximity are strongly recommended.
• An auxiliary earth electrode is provided electrically independent of all
other earthed metal, for example, constructional metalwork, pipes,
or metal-sheathed cables. This requirement is considered to be
fulfilled if the auxiliary earth electrode is installed at specified
distance from all other earthed metal
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
• The earthing conductor leading to the auxiliary earth electrode is
insulated to avoid contact with the protective conductor or any of the
parts connected thereto or extraneous conductive parts which are, or
may be, in contact with them.
• The protective conductor is connected only to the exposed conductive
parts of those items of electrical equipment whose supply will be
interrupted in the event of the protective device operating under fault
• Earthing arrangements for functional purposes are provided to
ensure correct operation of equipment or to permit reliable and
proper functioning of the installation.
• In TN system, for cables in fixed installation having a cross-sectional
area not less than 10 mm2 for both copper and aluminium, a single
conductor may serve both as protective conductor and neutral
conductor, provided that the part of the installation concerned is not
protected by a residual current-operated device.
• The minimum cross-sectional area of a PEN conductor may be 4
mm2, provided that the cable is of a concentric type conforming to
IEC standard and that duplicate continuity connection exist at all
joins termination in the run of the concentric conductors.
• The PEN conductors are insulated for the highest voltage to which it
may be subject to avoid stray currents.
• If from any point of the installation the neutral and protective
functions are provided by separate conductors, it is inadmissible to
connect these conductors to each other from that point. At the point
of separation, separate terminal or bars are provided for the
protective and neutral conductors. The PEN conductor is connected to
the terminal or bar intended for the protective conductor.
• Main equipotential bonding conductors have cross-sectional areas not
less than half the cross-sectional area of the largest protective
conductor of the installation, subject to a minimum of 6 mm2.
However, the cross-sectional area need not exceed 25 mm2 if the
bonding conductor is of copper or a cross-sectional area affording
equivalent current-carrying capacity in other metals.
• A supplementary equipotential bonding conductor connecting two
exposed conductive parts may have a cross-sectional area not less
than of the smaller protective conductor connected to the exposed
conductive parts.
• A supplementary equipotential boning conductor connecting exposed
conductive parts to extraneous conductive parts may have a cross-
sectional are not less than the cross sectional area of the
corresponding protective conductor.
• Supplementary equipotential bonding may be extraneous conductive
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
parts of a permanent nature, such as structural metalwork, or by
supplementary conductors, or by a combination of these.
• Wherever water pipes of building are used for earthing or as
protective conductors, the water meter is to be bonded across and
the bonding conductor shall be of appropriate cross- sectional area
according to its use as a protective conductor, equipotential bonding
conductor or functional earthing conductor.
The electrical Installation work should be carried out in accordance with
Standard & Code mentioned above. It is also in conformity with the
requirements of the Local Electricity Supply Authority. Electrical work in
general is carried out as per the employer requirements.
Wherever this specifications calls for a higher standard of material and or
workmanship than those required by any of the above mentions
regulations and specification then the specification here under takes
precedence over the said regulations and standards.
The details of scope of work subhead wise are given in the subsequent
paras. The tentative quantities worked out in schedule of quantities are
based on particular equipment considered at design stage. The contractor
is required to recheck the quantities based on equipment offered by him
to achieve required parameters.
The bidder should note that the specifications furnished in the tender is of
general nature only and it is the responsibility of the bidder to design,
supply, install and commission the equipment and services required for
the satisfactory performance of the installation. All the items of equipment
required for the safe and satisfactory operation of the installation is
supplied and Installed by the contractor.
2.4 Point Wiring
This section covers the general technical requirements of the various
components in Internal Electrical Installation Works.
2.4.2 Point Wiring
2.4.2.1 Definition
A point (other than socket outlet point) includes all works necessary in
complete wiring to the following outlets from the controlling switch or
MCB. The scope of wiring for a point, however, includes the wiring work
necessary in tapping from another point in the same distribution circuit: -
• Connector (in the case of points for ceiling/ exhaust fan points, pre-
wired light fittings and call bells/ Buzzer)
• Lamp holder (in the case of gooseneck type wall brackets, batten
holders and fittings which are not pre-wired.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
In the case of call bell points, the words “from the controlling switch or
MCB” are read as “from the connector meant for connection to bell push”.
Dedicated circuits for different loads such as lighting, AC Units & Power
circuits are to be provided.
a) Following are deemed to be included in point wiring :
o Conduit, accessories for the conduit and wiring cables between
the switch box and point outlet, loop protective earthing of each
fan/ light fixture.
o All fixing accessories such as clips, nails, screws, Phil plug, rawl
plug etc. as required.
o Metal switch boxes for control switches, regulators, sockets etc.
recessed or surface type and outer & inner cover plates in case of
modular type switches.
o Outlet boxes, junction boxes, pull-through boxes etc. but
excluding metal boxes if any, provided with switchboards for
loose wires/ conduit terminations.
o Control switch or MCB as specified.
o Connector as required.
o Connections to connector, lamp holder, switch etc.
o Interconnection wiring between points on the same circuit, in the
same switch box or from another.
o Protective (loop earthing) conductor from one metallic switch box
to another in the distribution circuits, and for socket outlets.
o Based conduit or porcelain tubing where wiring cables pass
through wall etc.
b) Following are deemed to be included in group control point wiring :
o Conduit, accessories for the conduit and wiring cables between
the Switchboard/ MCB DB to the first point or wiring cable
between points forming a group including loop protective
earthing of each fan/ light fixture.
o All fixing accessories such as clips, nails, screws, Phil plug, rawl
plug etc. as required.
o Hexagonal type junction boxes, pull-through boxes etc.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
o Connectors as required.
o Connections to connector & Switch/ MCB etc.
o Bushed conduit or porcelain tubing where wiring cables pass
through wall etc.
c) Ferrule is to be provided at both ends i.e. on switchboards/DB’s as
well as on fittings / fixture side.
d) All the wires should be terminated with copper lugs on both sides i.e.
on switchboards/DB’s as well as on fittings / fixture side.
2.5 Circuit and Sub main Wiring
2.5.1 Circuit Wiring
Circuit wiring means the wiring from the distribution board upto the
tapping point for the nearest first point of that distribution circuit, viz.
upto the nearest first switch box.
2.5.2 Sub main Wiring
Sub main wiring means the wiring from one Main/Distribution switchboard
• As far as, practicable circuit wiring and point wiring is drawn in
different conduit.
• Circuit wiring and sub main wiring should not run in the same
2.5.3 Other Wiring Works
Except as specified above for point wiring, circuit wiring and sub main
wiring, other types of wiring, wherever required shall be done as per the
2.5.4 System of Distribution and Wiring
The main distribution board and branch distribution board are controlled
or shall be provided with linked switch fuse unit or miniature circuit
breaker (MCB) of specified rating on the phase or live conductor or
combined phase and neutral control gear for incoming and outgoing as
indicated in the approved drawings.
Distribution of sub main and circuits.
As per final approved single line diagram.
2.5.5 Balancing of Circuits
The balancing of circuits in three wire or poly phase installations are
arranged before handling to the satisfaction of the Engineer-In-Charge.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
2.5.6 Wiring System
a. Unless and otherwise specified in the tender documents, wiring is done
only by the “Looping System”. Phase of live conductors are looped at
the switch boxes and neutral conductors at the point outlets.
b. Lights, fans and call bell are wired in the ‘lighting’ circuits. 15 Amp
socket outlets and other power outlets are wired in the ‘Power’ circuits.
13 Amp socket outlets are wired in the ‘lighting circuits’.
c. The wiring throughout the installation is such that there is no break in
the neutral wire except in the form of linked switchgear
d. The wiring is segregated as Essential and non-essential in all the
building except in the case of residential quarters.
2.5.7 Run of Wiring
The type of wiring is as specified in tender document, i.e. through
Surface wiring runs, as far as possible, along the walls and ceiling so as to
be easily accessible for inspection.
In no case, the open wiring is run above the false ceiling without the
approval of Engineer-In-Charge.
In all types of wiring, due consideration is given for neatness, good
appearance and safety.
2.5.8 Passing through walls or floors
When wiring cables are to pass through a wall, these are taken through a
protection (Steel/PVC) pipe or porcelain tube of suitable size such that
they pass through in a straight line without twist or cross in them on
either end of such holes. The ends of metallic pipe are neatly bushed with
porcelain, PVC or other approved material.
Where a wall pipe passes outside a building so as to be exposed to
weather, the outer end is bell mouthed and turned downwards and
properly bushed on the open end.
All floor openings for carrying any wiring is suitably sealed after
2.5.9 Joints in Wiring
a) No bare conductor in phase and/or neutral or twisted joints in phase,
neutral, and/or protective conductors in wiring are permitted.
b) There should not be any joints in the through runs of cables. If the
length of final circuit or sub main is more than the length of a
standard coil, thus necessitating a through joint, such joints are
made by means of approved mechanical connectors in suitable
junction boxes.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
c) Terminations of multi-stranded conductors are to be done using
suitable crimping type thimbles.
2.6 Conformity to Codes and Standards
a) All electrical works are carried out in accordance with the provisions
of codes and standard, amended upto date.(as detailed herein above)
b) The works also have to conform to installation standards regulations
of Maldives energy Authority.
2.7 General Requirements of Components
2.7.1 Quality of Materials
All material and equipment supplied by the Contractor shall be new.
They are of such design, size and materials as to satisfactorily function
under the rated conditions of operation and to withstand the
environmental conditions at site.
2.7.2 Conformity of Standards
a) All components must conform to installation regulations of Maldives
energy Authority Standard Specification, wherever existing.
However, for conduits, wiring cables, piano switches and socket
outlets, ISI marked materials are only permitted.
b) The installation standards regulations of Maldives energy Authority,
including amendments or revisions thereof upto the date of tender
acceptance, is applicable.
2.7.3 Inter changeability
Similar parts of all switches, lamp holders, distribution fuse boards,
switchgears, ceiling roses, brackets, pendants, fans and all other
fittings of the same type should be interchangeable in each installation.
2.8.1Wiring Cables
a. Conductors of wiring cables (other than flexible cables) shall be of
aluminium or copper, as specified.
b. Stranded aluminium conductor is not to be used in wiring cables upto
and including 6 Sq.mm. sizes.
c. Unless and otherwise specified, copper conductor of size 1.5 Sq.mm.
and above used for wiring is stranded and only FRLS type wiring
cables are to be used.
2.8.2 Flexible Cables
a) Conductors of flexible cables shall be of copper. The minimum cross
sectional area of conductor for flexible cable is 0.0006 Sq. inch
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
b) Only 3 core flexible cables are to be used for connecting single-phase
c) Unless armoured, or tough rubber, or PVC sheath mechanically
protects the flexible cables, these are not to be used where they are
liable to mechanical damage.
d) Flexible cable connection to bell push from ceiling rose is to be taken
through steel conduit/ metallic casing and capping.
2.9 Wiring Accessories
2.9.1Control Switches for Points
a. Combined switch cum sockets are not permitted.
b. Control switch is placed only in the live conductor of the circuit. No
single pole switch shall be inserted in the protective (earth)
conductor, or earthed neutral conductor of the circuit.
2.9.2Socket Outlets
13A and 15A 6 Pin socket outlets are to be installed at the following
positions, unless otherwise specified.
a. Kitchen/ Pantry 23 cm above working platform and away from the
likely positions of stove and sink.
b. At all other places – 23 cm above floor level.
2.9.3Switch box covers
Phenolic laminated sheet of 3 mm thick of approved shade shall be used
for switch box covers in case of piano type switches. For modular type
switches/sockets suitable outer and inner cover plates as specified shall
be provided over the standard box as recommended by the
manufacturers of modular type switch/ sockets and no separate sheet
cover is required to be provided.
2.9.4 Lamp Holders
The standard constructional feature of manufacturers (ISI approved) of
lamp holders is acceptable. Wherever the lamp holders are part of light
fixtures, the holders shall be suitable for the type of lamps used.
The type of fittings shall be as specified in Finishing Schedule/ Tentative
Bill of Quantities of tender documents.
2.10.1 Indoor Type Fittings
a) The contractors should supply the specified model and make of the
fittings. The standard constructional features of specified make and
model as given in the tender document shall be acceptable.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
b) Wherever conductors are required to be drawn through tube or
channel leading to the fitting, the tube or channel must be free from
sharp angles or projection edge, and of such size which will enable
them to be wired with the conductors used for the final circuit
without removing the braiding or sheathing. As far as possible all
such tubes or channels should be of sufficient size to permit looping
c) Pendants in verandahs and similar situations exposed to wind shall
be of fixed rod type.
d) Fittings are to be installed such that the lamp is at a height specified
in approved drawings or as directed by the Engineer-In-Charge.
2.11 Attachment of Fittings and Accessories
2.11.1 Conduit Wiring System
a. All accessories like switches, socket outlets, call bell pushed and
regulators are to be fixed in flush pattern inside the switch/ regulator
boxes. Accessories like ceiling roses, brackets, batten holders, stiff
pendants etc. shall be fixed on metal outlet boxes.
b. Brass screws shall be used to fix the accessories to their bases.
c. The switch box/ regulator box shall be normally mounted with their
bottom 1.25 m from floor level, unless otherwise directed by the
Engineer-In-Charge.
2.11.2 Fixing of Walls and Ceiling
a. PVC sleeves/ dash fasteners should normally be used for fixing to
walls or ceiling.
b. Plugging of walls or ceiling are to be done in a better way where
neatness is the first consideration. In all such cases, an approved
type of asbestos or fiber fixing plug (rawl or Phil plug) with correct
size of tools shall be used and done in a workmanlike manner.
2.11.3 Workmanship
Good workmanship is an essential requirement to be complied with. The
entire work of manufacture/ fabrication, assembly and installation must
conform to sound engineering practice.
The work is to be carried out under the direct supervision of an engineer,
employed by the contractor, who rectifies then and there the defects
pointed out by the Engineer-In-Charge during the progress of work. The
qualification of engineer or supervisor for over all supervision and to take
instructions from the Engineer-In-Charge is as specified in the special
2.12 Testing of Installation
All the completed installations are to be tested as per specifications for
“Testing of Installation”.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
2.12.1 Drawings
a) The work shall be carried out in accordance with the drawings
enclosed with the tender documents and also in accordance with
modification there to from time to time as approved by the Engineer-
In-Charge or as per the drawing prepared by the client based on
inventory and approved by Engineer-In-Charge.
b) All wiring diagrams are deemed to be ‘Drawings’ within the meaning
of the term as used in the Conditions of Contract. They indicate the
main switchboard, the distribution boards (with circuit numbers
controlled by them), the runs of various mains and sub mains and
the position of all points with their controls.
c) All circuits are to be indicated and numbered in the wiring diagram
and all points shall be given the same number as the, circuit to which
they are electrically connected.
2.13 Commissioning of Completion
Before the workman leaves the work finally, he must make sure that the
installation is commissioned, after due testing.
2.13.1 Completion Plan and Completion Certificate
a. For all work completion certificate after completion of work as
required by client is to be submitted to the Engineer-In-Charge.
b. Completion plan drawn to a suitable scale in tracing sheet with three
blue print copies of the same are also to be submitted.
(i) General Layout of the building.
(ii) Locations of main switchboard and distribution boards.
(iii) Position of all points and their controls indicating the circuit
numbers controlled by them.
(iv) Types of fittings, viz. fluorescent, pendants, brackets,
bulkhead, fans and exhaust fans etc.
(v) Name of work, job number, accepted tender reference, actual
date of completion, names of Division/Sub-Division, and name
of the firm who executed the work with their signature.
(vi) Final as built SLD / drawings.
3 Distribution Boards
a) The DB shall be protected by a cover with degree of protection of at
least IP 30 for indoor case and IP 65 for outdoor case.
b) DB is to be fixed at a height between 1.5 to 1.8m. However in the
case of DBs with multiple rows, the lowest point shall not be less
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
c) The Distribution Board must include at least the following
switching and control devices:
(i) A Power Control Switch that cuts the power supply in case the
power withdrawn overshoots the contracted capacity.
(ii) A main switch circuit breaker, omnipolar, with capability for
manual operation and equipped with protection against
overloading and short-circuits. This circuit breaker is
independent from the Power Control Switch.
(iii) A residual current device, which protects the Electrical
Installation against indirect contacts in any of the circuits by
automatically disconnecting it from the power supply.
(iv) Individual omnipolar circuit breaker to protect each of the circuits
that form the Electrical Installation in-house.
(v) Any specific control device that may be required for the
application of the selected electricity tariff to the Electrical
(vi) Optionally, the DB may also include a device for protection
against overvoltage.
d) Every socket must be wired to the DB with a phase wire along with
the earth and neutral wire. At the DB, the circuit breaker must be
appropriately sized for the socket and it should not be higher than
what is required for the socket.
In a building the earth wire connected to ground should be appropriately
thick to allow wheeling the foreseen short-circuit current in the electrical
installation, including lightning discharges. The main earth wire should
originate from the distribution board (DB) or the main switch via the
assigned site. The earth wire should be connected solidly to the earth rod.
Inspection chamber is to be provided for testing of main earthing.
4 Lighting Fixtures, Ceiling Fan, Exhaust Fan & Buzzer
4.1 LED Light Fittings
LED type light fittings are used for internal & External illumination to
achieve the desired Lux level as per the below mentioned Technical
Recommended requirement
No. Parameters
Efficiency of LED light
1 Min 95 Lumens / Watt
fitting (Efficacy)
2 Life of LED light fitting Not less than 50000 burning Hours
Approved make for
3 As per approved list of make.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
Recommended requirement
No. Parameters
CRI (Color Rendering Min 80 for indoor applications and Min 70 for
Index) outdoor applications.
THD (Total Harmonic
5 Less than 10 %
Extruded aluminium housing for indoor
6 Type of Housing applications. High pressures die cast aluminium for
outdoor applications.
IP 20 or higher for indoor applications and IP 65 or
higher for outdoor applications.
To be provided confirming to relevant IEC 61643-II
8 Surge Protection
class - 2 & EN 61643- II Type - 2.
Manufactures Name / Logo engraved / Embossed
Labeling / on housing / body or Name / Logo on aluminium
identification Mark plate Labels or Name / Logo printed on housing /
5 years warrantee from actual date of completion
10 Warrantee period of work on complete luminaire including driver /
control gear, LED, all accessories etc.
11 Lumens depreciation Up to 5 % per year and max 30%.
Note: The LED lighting fixtures/luminaire is tested in NABL accredited lab
for the parameters given below:
5 IES LM - 79 -08 with up to date corrections / amendments /
addendum covering:
a. Measurement of total luminous flux (Lumen).
b. Measurement of Luminous efficacy (Lumen/watt).
c. Measurement of chromaticity, Correlated color temperature (CCT) &
Color Rendering Index (CRI).
d. Measurement of Luminous intensity distribution.
e. Measurement of Electrical Power, Input voltage and current.
6 IES LM - 80 -08 with up to date corrections / amendments /
addendum covering:
a. Measurement of LED packages, Arrays and LED modules.
b. Measurement of Lumen maintenance life of LED light source.
c. Measurement of Temperature for LED packages.
7 IES LM - 82 -12 with up to date corrections / amendments /
addendum covering:
a) Measurement of performance of the LED light engine and
integrated lamp as a function of temperature.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
8 IES TM -21 -11 with up to date corrections / amendments /
addendum covering:
a. Measurement of Lumen maintenance life projection.
b. Measurement of Temperature data interpolation.
9. The tests includes:-
(i) Meggar test
(ii) Continuity test
(iii) Polarity test and phase sequence test
10. Inspection & Verification
10.1 Initial and periodic inspections and verifications
10.1.1 Inspection and verification requirements
a) All Electrical Installations undergoes inspection by the MEA or the
agent authorized by the MEA in two timeframes:
o Initial inspections: verifications prior to the commissioning of the
Electrical Installation.
o Periodic inspections: verifications during the useful life of the
Electrical Installation at regular intervals.
b) All Electrical Installations undergoes initial verification prior to their
commissioning by the authorized installer.
c) The authorized installer, authorized by the MEA, is responsible for the
proper execution of the installation, granting its safety.
d) The owners of an Electrical Installation are responsible for their
maintenance in good and safe operating conditions.
10.1.2 Frequency of Inspections
a) All Electrical Installations with MIC or MEC higher than 500 kW
undergoes periodic inspection by the MEA or its authorized agents at
least once every five (5) years.
b) All Electrical Installations with MIC or MEC equal or lower than 500
kW undergoes periodic inspection by the MEA or its authorized
agents at least once every ten (10) years.
c) The MEA may perform inspections at any given moment if so
required to comply with its regulatory functions and subject to
notifying in writing the owner of the Electrical Installations to be
inspected at least ten (10) Business Days in advance.
10.1.3 Payment for inspection and verification
The costs associated to the development of the activities of initial and
periodic inspection and verification of electrical equipment shall be borne
by the owner of the equipment/ Contractor, including the payment of fees
to the MEA’s staff or MEA authorized personnel that carry out the
mentioned activities.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
10.1.4 Types and characteristics of verifications
a) Verification activities are performed in a two-step approach:
o Verification by examination.
o Verification by measure
b) The verification by examination:
o Is performed prior to the verification by measure;
o Covers the whole Electrical Installation and while it is not
energized, unless specifically requested.
c) IT verifies the following:
i. Whether the material and equipment installed are actually in
accordance with the provisions and requirements of the technical
project design;
ii. Whether the material and equipment have been installed following
the prescriptions and requirements of this Installation Standards
and the manufacturer’s recommendations;
iii. Whether the material and equipment installed present any fault or
visible defect which may impact safety of persons or equipment and
d) In particular, verifications by examination includes:
(i) Verification of the protective measure against Electric Shock
installed, either by direct contact or by faults in the insulation
(ii) The presence, condition and calibration of protective and
signaling devices:
(iii) The presence and condition of protections against thermal
effect and fires;
(iv) The use of adequate materials and measures to protect the
Electrical Installation against external agents;
(v) The presence and characteristics of schemes, panels and
similar information tools to communicate dangers and safety
measures to persons;
(vi) The location and characteristics of switchgear and relays;
(vii) The correct execution of wiring connections;
(viii) The adequate access to the Electrical Installation for inspection,
operation and maintenance.
e) The verification by measure includes at least:
(i) Verification of the continuity of protective wiring;
(ii) Measurements of the earthing impedances;
(iii) Measurements of the insulation level of conductors and other
(iv) Measurement of the dielectric strength of transformers’ oil and
switchgear’s oil (if any & where it is necessary),
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
(v) Verification of the phase sequence of alternate current systems;
(vi) Any other specific measurements recommended by the
manufacturer or required by the regulation in force in the
Republic of Maldives.
f) Inspection and testing of low voltage Electrical Installations are
based on the requirements of IEC 60364-6.
g) Inspection and testing of medium voltage Electrical Installations are
based on the requirements of IEC 60060 and the IEC standards
applicable to each electrical equipment.
h) Inspection and testing of Generating Stations are based on the
requirements of the IEC standard applicable to each type of
generation equipment, notably:
o Power transformers: IEC 60076;
o PV Generating Stations: IEC 60904 and IEC 62446;
o Wind Generating Stations: IEC 61400;
o Steam turbines: IEC 60045; and
o Rotating generator engines: IEC 60034.
10.1.5 Reporting on inspections and verifications
a) After each inspection or verification action, the agent responsible for
carrying out the inspection or verification shall submit to the MEA
(when the inspection or verification was not carried out directly by
the MEA’s personnel) and to the owner of the Electrical Installation
inspected or verified, a Inspection Report or Verification Report
containing at least but not limited to the following:
o Identification of the Electrical Installation inspected or verified;
o Name and stamp of the agent who performed the inspection or
o Date and time the inspection or verification was performed;
o List and descriptions of the elements inspected or tested and the
inspection or verification actions carried out;
o Detailed summary of the outcomes of the inspection or
verification actions;
o Environmental conditions during the inspection or verifications
and description of equipment utilised (if any); and
o Signature of at least a representative of each of the agents
present during the inspection or verification.
b) The Inspection Report or Verification Report is to be sent to the MEA
and to the owner of the Electrical Installation in writing (soft or hard
copy) not later than ten (10) Business Days after the finalization of
the inspection or verification.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
11 On-demand inspections and verifications
11.1 Procedure for inspection and verification on-demand
a) The Service Provider, the owner of the electrical equipment, the
Customer if different than the owner, or eventually the MEA, can
request on-demand that inspection and verification are performed on
electrical equipment.
b) On demand inspection and verification activities complies with the
same technical requirements set for initial and periodic verification
c) The owner of the premises where the electrical equipment is located
will grant access to the electrical equipment to the parties involved:
the Service Provider personnel, the Customer or its representatives,
the MEA or its representatives and any other agent that is involved in
the inspection and verification activities.
d) The agent that will carry out the inspection and verification activities
shall be present along with the other parties the characteristics of the
activities to be performed, their objective, and the procedure that will
e) In case of metering equipment:
o The Operator of the Distribution Network is in charge of sealing
and unsealing it whenever necessary.
o In case the inspection and verification requires tests that cannot
be performed in situ, the electrical equipment is removed by the
Operator of the Distribution Network, packed and sealed, and
sent to the place where the tests are to be performed.
o Immediately after removal of the meter, a substitute shall be
installed by the Operator of the Distribution Network until the
original is ready for its re-installation. Particular attention is put
to the multipliers utilized by the meter in registering data from
the CTs and VTs, if any.
f) On demand inspection and verification activities are subject to the
same reporting requirements as initial and periodic inspection and
verification activities.
11.2 Payment for inspection and verification
The cost of on-demand inspections and verifications will be initially borne
by the applicant, including the payment of fees to the MEA’s staff or MEA
authorized personnel that carries out the mentioned activities, and will be
ultimately borne:
a) By the party who requested the on-demand inspection and
verification in case the results of the inspection and verification
activities demonstrate that the electrical equipment met all the
technical requirements; or
b) By the owner of the electrical equipment in case the results of the
inspection and verification activities demonstrate that the electrical
equipment did not meet all the technical requirements.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
12 Testing of Installation
On completion of installation, the following tests are carried out :-
a. Insulation resistance test.
b. Polarity test of switch.
c. Earth continuity test.
d. Earth electrode resistance test.
12.1.2 Witnessing of Tests
Testing shall be carried out for the completed installations, in the presence
of and to the satisfaction of the Engineer-In-Charge by the Contractor. All
test results shall be recorded and to be submitted to the Department.
13 Insulation Resistance
The tests described below are to be performed before the installation are
permanently connected to the supply. For these tests large installations
may be divided into groups of outlets, each containing not less than 50
outlets. For the purposes of this code the term ‘outlet’ includes every
point and every switch except that a socket outlet, appliance or luminaire
incorporating a switch is regarded as one outlet. The test voltage for
insulation resistance measurement is 500 V.
When measured with all fuse links in place, all switches (including, if
practicable, the main switch) should be closed and all poles or phases of
the wiring electrically connected together, the insulation resistance to
earth shall not be less than 1 mega ohm.
When measured between all the conductors connected to any one phase
or pole of the supply and in turn, all conductors connected to each other
phase or pole the insulation resistance shall not be less than 1 mega ohm.
Wherever practicable, so that all parts of the wiring may be tested, all
lamps are removed and all current-using equipment is disconnected and
all local switches controlling such lamps or other equipment is closed.
Where the removal of lamps and/or the disconnection of current-using
equipment are impracticable, the local switches controlling such lamps
and/or equipment is open. Particular attention is to be given to the
presence of electronic devices connected in the installation and such
devices are to be isolated so that the test voltage does not damage them.
Wherever equipment is disconnected for the tests prescribed above, and
the equipment has exposed conductive parts required by these clauses to
be connected to protective conductors, the insulation resistance between
the exposed conductive parts and all live parts of the equipment shall not
be measured separately and should comply with requirements of the
appropriate Maldivian Standard and the insulation resistance shall not be
less than 0.5 mega ohm.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
14 Polarity Test of Switch
In a two wire installation, a test is to be performed to verify that all the
switches in every circuit have been fitted in the same conductor,
throughout, and such conductor, is labeled or marked for connection to
the phase conductor, or to the non-earthed conductors of the supply.
In a three wire or a four wire installation, a test is to be performed to
verify that every non-linked single pole switch is fitted in a conductor
which is labeled, or marked for connection to one of the phase conductors
The installation is connected to the supply for testing. The terminals of all
switches shall be tested by a test lamp, one lead of which is to be
connected to the earth. Glowing of test lamp to its full brilliance, when
the switch is in ‘ON’ position irrespective of appliance in position or not,
indicates that the switch is connected to the right polarity.
15 Testing of Earth Continuity Path
The earth continuity conductor, including metal conduits and metallic
envelops of cables in all cases, are to be tested for electric continuity. The
electrical resistance of the same along with the earthing lead, but
excluding any added resistance or earth leakage circuit breaker, measured
from the connection with the earth electrode to any point in the earth
continuity conductor in the completed installation shall not exceed one
16 Measurement of Earth Electrode Resistance
Two auxiliary earth electrodes, besides the test electrode, are placed at
suitable distance from the test electrode. A measured current is passed
between the electrode ‘A’ to be tested and an auxiliary current electrode
‘C’ and the potential difference between the electrode ‘A’ and auxiliary
potential ‘B’ is measured. The resistance of the test electrode ‘a’ is then
Where, R- Resistance of the test electrode in ohms
V- Reading of the voltmeter in volts
I- Reading of the ammeter in amps
a) Stray currents flowing in the soil may produce serious errors in the
measurement of earth resistance. To eliminate this, hand driven
generator shall be used.
If the frequency of the supply of hand driven generator coincides
with the frequency of stray current, there will be wandering of
instrument pointer. An increase or decrease of generator speed will
cause this to disappear.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
b) At the time of test, the test electrode shall be separated from the
earthing system.
c) The auxiliary electrodes are of 13mm diameter mild steel rod driven
upto 1 m into the ground.
d) All the three electrodes are to be so placed that they are independent
of the resistance area of each other. If the test electrode is in the
form of a rod, pipe or plate, the auxiliary current electrode C are
placed at least 30 m away from it and the auxiliary potential
electrode ‘B’ is placed mid-way between them.
e) Unless three consecutive readings of test electrode resistance agree,
the test is repeated by increasing the distance between electrodes A
and C upto 50 m, and each time placing the electrode B mid-way
f) On these principles, “Megger Earth Tester” containing a direct
reading ohm-meter, a hand driven generator and auxiliary electrodes
are manufactured for direct reading of earth resistance of electrodes.
17 Test Certificate
On completion of an electrical installation or an extension to an
installation, a certificate is to be furnished by the Contractor,
countersigned by the certificate supervisor under whose direct supervision
the installation has been carried out. The certificate shall be in the
prescribed form in addition to test certificate required by the local
Electricity supply authorities.
18 Form of Completion Certificate
I/We certify that the installation detailed below has/have been installed by
me/us and tested and that best of my/ our knowledge and belief. It
complies with Maldivian Electricity Rules 1956, as well as the Contract
Specifications.
Electrical Installation at ______________________________________
Voltage and system of supply _________________________________
18.1 Particulars of work
18.1.1 Internal Electrical Installation
No. Total Load Type or system of wiring
i) Light point
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
iii) Plug point
b) 3 pin 15 Amp
18.1.2 If the work involves installation of underground cable
Total length of underground cable & its size.
No. of Joints : End Joint :
St. through joint :
18.1.3 Earthing
a) Description of earth electrodes.
b) Number of earth electrodes.
18.1.4 Test Results of Wiring
a) Insulation resistance.
i. Insulation resistance of the whole system of conductors to
earth______________ Mega ohms
Insulation between the phase conductor and neutral
Between phase R and neutral . Mega ohms
Between phase Y and neutral . Mega ohms
Between phase B and neutral . Mega ohms
ii. Insulation resistance between the phase conductors in case of poly
Between phase R and neutral . Mega ohms
Between phase Y and neutral . Mega ohms
Between phase B and neutral . Mega ohms
b) Polarity test
Polarity of non-linked single pole branch switches.
c) Earth continuity test
Maximum resistance between any points in the earth continuity conductor
including metal conduits and main earth lead ….………….ohms.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
d) Earth electrodes resistance
Resistance of each earth electrode
iii) . . . . ohms
e) Lightning Protective System
Resistance of the whole of lightning protective system to earth before any
bonding is effected with earth electrodes and metal in/on the
structure….…………. ohms.
19. Capacity of Light and Power Circuit
a) Lighting circuit shall not contain more than 10 points of light, fan, socket
outlet or connected load of 800 W whichever is less.
b) Power circuit is to be designed based on load where specified, otherwise
the norm of one (1) kW per circuit is to be followed.
c) Not more than 2 power outlets shall be connected in one power circuit in
the case of residential buildings.
d) Not more than one power outlet shall be connected to one circuit in the
office areas, rest rooms etc.
e) Power outlets in common areas like security hold, concourse, arrival/
departure and passenger areas shall be two power outlet per circuit. One
outlet is looped from other outlet.
f) In the case of pictographs and signages, these shall be connected as a
group control point from the nearest light point and classified as group
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
APPENDIX - I : TERMINOLOGY
This appendix indicates some of the commonly used and important terms,
relevant for the Internal EI works.
a) Exposed conductive part - A conductive part of electrical
equivalent, which can be touched and which is not normally live, but
which may become the earth potential.
b) Direct contact - Contact of persons or livestock with live parts which may
result in electrical shock.
c) Indirect Contact - Contact of persons or livestock with exposed
conductive parts made live by a fault and which may result in electric
d) Live Part - A conductor or conductive part intended to be energized in
normal use, including a neutral conductor but, by convention, not a PEN
e) Touch Voltage - The potential difference between a grounded metallic
structure and a point on the earth surface separated by a distance
equal to the normal maximum horizontal reach of approximately 1
f) Danger - Danger to health or danger to life or limb from shock, burn
or injury from mechanical movement to persons (and livestock where
present), or from fire attendant upon the use of electrical energy.
g) Earth - The conductive mass of the earth, whose electric potential at
any point is conventionally taken as zero.
h) Earth electrode - A conductor or group of conductors in intimate
contact with and providing an electrical connection to earth.
i) Earth fault loop impedance- The impedance of the earth fault current
loop (phase to earth loop), starting and ending at the point of earth fault.
j) Earth leakage current - A current which flows to earth, or to
extraneous conductive parts, in a circuit which is electrically sound.
k) Earth conductor - A protective conductor connecting the main earth
terminal to an earth electrode.
l) Residual current - The algebraic sum of the instantaneous values
of current flowing through all the live conductors of a circuit at a
point of the electrical installation.
m) Residual current device (RCD) - A mechanical switching device,
intended to cause the opening of the contacts when the residual current
attains a given value under the specified conditions.
n) Switchboard- An assembly of switchgear with or without instruments,
but the term does not apply to a group of local switches in a final circuit.
o) Switchgear - An assembly of main and auxiliary switching apparatus for
operation, regulation, protection or other control of electrical installations.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
APPENDIX-II : SAFETY PROCEDURE
a) The Maldivian Electricity Rules 1956, as amended upto date, are to be
followed in their entirety. Any installation or portion of installation which
does not comply with these rules should be got rectified immediately.
b) The detailed instructions on safety procedures given in B.I.S. Code No.
5216-1969-"Code of Safety Procedures and Practices in Electrical Works"
are strictly followed.
c) No inflammable materials shall be stored in places other than the rooms
specially constructed for this purpose in accordance with the provisions of
Maldivian Explosives Act. If such storage is unavoidable, it should be
allowed only for a short period and in addition, special precautions, such
as cutting off the supply to such places at normal times, storing
materials away from wiring and switch boards, giving electric supply for a
temporary period with the permission of consultants are taken.
d) The electrical switchgears and distribution boards should be clearly
marked to indicate the areas being controlled by them.
e) Before energizing on an installation after the work is completed, it
should be ensured that all tools have been removed and accounted,
no person is present inside any enclosure of the switch board etc. any
earthing connection made for doing the work has been removed.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
APPENDIX –IV: ABBREVIATIONS
The following abbreviations have been used in the accompanying
Specifications, drawings and Schedule of Quantities.
CU Stands for copper.
GI Stands for Galvanized Iron (Mild Steel)
V Stands for Volts
MV Stands for Medium Voltage (110 V ,230 V ,415 V, 600 V)
LV Stands for Low Voltage (32 V & Below)
LT Stands for Low Tension
PVC Stands for Polyvinyl Chloride
AMP Stands for Amperes
KWH Stands for Kilowatt Hours
KW Stands for Kilo Watts
EE Stands for Institution of Electrical Engineers - London
NEC Stands for National Electrical Code
VCB Stands for Vacuum Circuit Breaker
ACB Stands for Air Circuit Breaker
RCCB Stands for Earth Leakage Circuit Breaker
MCB Stands for Miniature Circuit Breaker
MCCB Stands for Moulded Case Circuit Breaker
SP Stands for Single Pole
DP Stands for Double Pole
TP Stands for Triple Pole
TPN Stands for Triple Pole and Neutral
4 Pole Stands for 3 phase and neutral of same capacity (size)
MDB Stands for Main Distribution Board
SDB Stands for Sub Distribution Board
FDB Stands for Final Distribution Board
MCC Stands for Motor Control Centre
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
TECHNICAL SPECIFICATION - LIFT WORKS
20.1 PASSENGER ELEVATORS: (S + 16 & Terrace) - Two BHK Cluster
Supply, Installation, Testing and Commissioning of 8 Nos. Passenger (Minimum)
Elevator, in lift shaft of dimensions 1800(W) X1900(D), 544 Kg, with Variable
Voltage Variable Frequency (VVVF) drive having a speed of 1.5 metre/ sec and travel
height of 52.15 m with 18 Stops and Microprocessor based control suitable for
operation on 415 V, 50 Hz, 3 phase A.C. electric Supplying as required.
1. Type of machine Gearless, Machine room less
2. Capacity 544 Kg
3. Number of Passengers 8 Nos. (minimum)
4. Speed 1.5 mps (minimum)
5. No of landing 18 Landings (Stilt+ 16 Floors +
6. Number of openings 18 on the same side.
7. Travel approx. 52.15 meter
8. Power Supplying 415V/240V, 50HZ
9. Acceptable voltage Fluctuation +10% to -20%
10. Rate of Acceleration 0.6-1.5 (adjustable at site)
/deceleration (m/sec2)
11. Jerk (m/sec2) 0.7-1.5 (adjustable at site)
12. Vibration in car horizontal 20/18 MG maximum
13. Vibration in car vertical 20/18 MG maximum
14. Noise level in car 48dbA max.
15. Door noise level while 52dbA max. at a distance of
closing and opening 1.0 metre from car door and 1.5
metre from floor level
16. Type of Drive: Variable Voltage Frequency Drive V3F.
17. Location of Machine Room: Machine Room Less (MRL)
18. Indicators car & landings: 7 Segment 25mm digital direction and indicators in car
and at all landings.
19. Automatic Rescue Device (ARD) with dry maintenance free batteries
20. Call register type KDS-50 Micro pushbutton for Car and landing.
21. 3-Way Intercom
22. Manual Cranking operation
23. Integral shaft for gear and motor
24. Emergency Stop Button
25. CVT/Built Voltage Stabilizer (Constant Voltage Transformer)
26. Pit ladder and balustrade
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
27. Flooring: Provision for Granite flooring with 19mm recess.
28. Emergency cabin lighting and alarm.
29. Emergency call system
30. FRD/Fire Man Drive (Fire Rescue Device)
31. Controls: Resolve Micro Processor based full collective control with or without
attendant operation.
32. Door Safety: PANA 40-Full ray curtain for car door safety.
33. Load weighing device with indicator & bypass function.
34. Lift Announcement System (LAS)
35. Safety gears & over speed governor
36. Infra-red door safety device
37. Door - Double door Centre opening
38. Civil works: All minor civil works such as scaffolding, making holes, grouting,
concreting etc.
39. Provision for connectivity of CCTV.
20.2 FIRE / STRETCHER ELEVATORS: (S + 16 & Terrace) - Two BHK Cluster
Supply, Installation, Testing and Commissioning of 13 Nos. Fire Elevator / Stretcher
(Minimum) Elevator, in lift shaft of dimensions 1800(W) X2600(D), 884 Kg, with
Variable Voltage Variable Frequency (VVVF) drive having a speed of 1.5 metre/ sec
and travel height of 52.15 m with 18 Stops and Microprocessor based control suitable
for operation on 415 V, 50 Hz, 3 phase A.C. electric Supplying as required.
1. Type of machine Gearless, machine room less
2. Capacity 844 Kg
3. Number of Passengers 13 Nos. (minimum)
4. Speed 1.5 mps. (minimum)
5. No of landing 18 Landings (Stilt+ 16 Floors +
6. Number of openings 18 on the same side.
7. Travel approx. 52.15 meter
8. Power Supplying 415V/240V, 50HZ
9. Acceptable voltage Fluctuation +10 to -20%
10. Rate of Acceleration 0.6-1.5 (adjustable at site)
/deceleration (m/sec2)
11. Jerk (m/sec2) 0.7-1.5 (adjustable at site)
12. Vibration in car horizontal 20/18 MG maximum
13. Vibration in car vertical 20/18 MG maximum
14. Noise level in car 48dbA max.
15. Door noise level while 52dbA max. at a distance of
closing and opening 1.0 metre from car door and 1.5
metre from floor level
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
16. Type of Drive: Variable Voltage Frequency Drive V3F.
17. Location of Machine Room: Machine Room Less (MRL)
18. Indicators car & landings: 7 Segment 25mm digital direction and indicators in car
and at all landings.
19. Automatic Rescue Device (ARD) with dry maintenance free batteries
20. Call register type KDS-50 Micro pushbutton for Car and landing.
21. 3-Way Intercom
22. Manual Cranking operation
23. Integral shaft for gear and motor
24. Emergency Stop Button
25. CVT/Built Voltage Stabilizer (Constant Voltage Transformer)
26. Pit ladder and balustrade
27. Flooring : Provision for Granite flooring with 19mm recess.
28. Emergency cabin lighting and alarm.
29. Emergency call system
30. FRD/Fire Man Drive (Fire Rescue Device)
31. Controls: Resolve Micro Processor based full collective control with or without
attendant operation.
32. Door Safety: PANA 40-Full ray curtain for car door safety.
33. Load weighing device with indicator & bypass function.
34. Lift Announcement System (LAS)
35. Safety gears & over speed governor
36. Infra-red door safety device
37. Door - Double door Centre opening
38. Civil works: All minor civil works such as scaffolding, making holes, grouting,
concreting etc.
39. Provision for connectivity of CCTV.
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
LIFTS SCHEDULE FOR 600 UNITS SOCIAL HOUSING IN HULHUMALE,
2BHK Tower - (05 TOWER) - (S+16 Floors + Terrace)
SIZE PASSENGERS NO. OF TRAVEL
TYPE NO. WEIGHT
(WXD) PER LIFT LANDINGS HEIGHT
PASSENGER 1800 x 18 52.15 Mtr
LIFT 1900 LANDINGS (from Gr to
FIRE LIFT / (S+16 +
1800 X Terrace
STRETCHER 1 13 884 Terrace)
TOTAL NO. OF LIFTS
This specification covers manufacture, testing as may be necessary before
dispatch, delivery at site, all preparatory work, assembly and installations,
commissioning putting into operation of Lifts.
The Lifts/ Escalators are installed at Social Housing in Hulhumale, Maldives.
20.5 Data, Manual and Drawings by Contractor
(i) The contractor has to submit the following drawings for approval of
Engineer-In- Charge before commencement of installation.
(ii) All general arrangement drawings.
(iii) Details of foundations for the equipment, load data, location etc. of
various assembled equipment as may be needed generally by other
agencies for purpose of their work. The data will include breaking load
on guides, reaction of buffers on lift pits reaction on support points in
(iv) Complete layout dimensions for every unit / group of units with
dimensions required for erection purposes.
(v) Any other drawing / information not specifically mentioned above but
deemed to be necessary for the job by the contractor.
(vi) The contractor should furnish well in advance No. of copies (as
mentioned in SCC) of detailed instructions and manuals of manufactures
for all items of equipment’s regarding installation, adjustments operation
Signature of Contractor NBCC
Construction of 600 Nos (2BHK) Social Housing units in Hulhumale,
Republic of Maldives (Package-I)
Technical Specifications- Revised as per Corrigendum – Addendum 03
and maintenance i/c preventive maintenance & trouble shooting
together with all the relevant data sheets, spare parts catalogues and
workshop procedure for repairs, assembly and adjustments etc.
20.6 Extent of work
The work comprises of entire labour including supervision and all materials
necessary to make a complete installation and such tests and adjustments
and commissioning as per the requirement. The term complete installation
not only mean major items of the plant and equipment covered by
specifications but all incidental sundry components necessary for complete
execution and satisfactory performance of installation with all layout
charts whether or not those have been mentioned in details.
20.7 Inspection and Testing:
a) Initial and final inspection / testing are to be carried out as per General
Specifications.
b) Tests at manufacturer’s premises will be witnessed by Engineer-In-
c) Environmental test certificate for Controller & Automatic Rescue Devices
should be furnished from any accredited laboratory of Autonomous bodies
to prove to topicalization for the environment conditions as per rules of
d) Copies of all documents of routine and type test certificate of the
equipment, carried out at the manufacturers premises are to be furnished
to the Engineer-In-Charge.
After completion of the work in all respects the contractor offers the
installation for testing and operation for carrying out joint inspection and
will be carried out as per Specification.
20.8 Running in Period:
After satisfactory final inspection, the contractor demonstrates the trouble
free running of the installation for a period of not less than 30 days before
the overtaking each lift. During this period, the lifts are kept either in
automatic or manual mode. After the lift-installation has been operated
without any major breakdown for 30 days, the installation is taken after
getting approval by the Client. During this period i.e. 30 days, the lift is
deemed to have run trouble- free, if the numbers of breakdowns are not
more than four calls (excluding false calls and leveling defects).
20.9 Compliance with Regulations and Maldivian Standards.
All works are to be carried out in accordance with relevant regulation,
both statutory and those specified by the Maldivian Standards related to
the works covered by this specification.
Signature of Contractor NBCC
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