REPAIR/MAINTENACE DISTRIBUTION TRANSFORMER AND OTHER CONNECTED WORKS AT NSB, NP, AP, NCS, KEYPERSONNEL COLONY AND OTHER ALLIED AREAS UNDER AGE E/M-I OF GE(U-I) VISAKHAPTNAM

Amount

M&L for Disconnecting Inteligent Elecrtonic Device of any type / Make from 11 KV HT panel, cleaning the contacts , IED configuration , Calibration & Testing of all the measuring & protection devices viz., CTs, Relays and Meters at site. Testing of all the trip functions of the relays after final current settings by simulating fault current by CT Primary injection test set , checking of current transformer , rectification of defects in control wiring for proper tripping of CB during actual system fault conduction through relay & Tripping coil. Adjustment / setting to plug and time multiplier settings of IED to achieve the discrimination in tripping, tune/synchronies upstream breaker relay settings-installation of relay, testing & commissioning etc complete all as specified and as directed.

M&L for Collecting necessary required data & peak load details from IED of any type / Make from 11 KV HT panel , Transformer full load details during peak hours. Relay Setting Calculations & Co-Ordination Study. Unit Protection Setting of Transformers. Feeder wise settings has to be furnished & Report with Firm Recommendations to be submitted Down Stream Power distribution (Complete 11 KV system) overall co-ordinations of time need to be achieved. Adjustment / setting to plug and time multiplier settings of IED complete in all as specified and as directed.

Supply of CT's epoxy cast resin , with primary Current 100A - 50A/1 A , 1A , Secondary current 1A , Dual core , Dual Ratio. Protection core - Class 5P10 & Metering core - Class 0.5 , 2.5 VA . Suitable for ABB make RMU complete all as directed.

Dismantling of existing CT's , Installation of supplied CT's in Areva make HWX MODEL Panel & Commissioning by checking of current transformer as per IS 2705 ( Part 3 ).: 1992 and by primary injection up to 500A complete all as directed.

Supply and fix following all as directed

LED Indication Lamps

Closing coil / Shunt trip coil 110 V DC / 220 V DC

HRC fuses for PT primary side

Spring Charging motor

Multi function meter , Digital type

Busines 25KA for uniger cubicle

End cover for shroud on top of VCB - Vaccume Interupter

Bushing for VCB , Vaccume Intrupter (Part no 1VCR011580G0001)

Vaccume interupter

Contact Spring (1VCR005614F0001)

Shutter assembly

Trpping coil 110 V DC

Closing coil 110 V DC

Hinge Assly

Handle Unigear

Battery

Supply of 11kV /√3 / 110v/√3 Potential Transformers

Finger Type ARMS ASSEMBLY

Bus Bar with Insulation fit for PT Trolly

110V DC , 220V AC Aux Contactor for Control Logic

Breaker Control Switch (TNC)

Main Bus Bar shroud (11kV Grade)

Busbar Support Insulator - 25KA

Decarburizing/cleaning complete 11kV HT Bus bar chamber with electrical connections, complete bus bar from the bus bar chamber , Cleaning with CTC and ensure proper decarburizing up to proper megger value , refixing the same after applying Backtol Red solution to the bus bar insulator & checking all the connections , tightening the nuts , bolts complete incl replacement of defective rusted bolts & nuts all as specified and directed.

Control Wiring up to Control Chamber with 1 Core , 2.5Sq mm Cu cable with proper ferules & appropriate Lugs.

Supply & replacement, calibrating, testing, commissioning of Micro processor feeder protection relay, range - 0.01In – 8In, protection setting- 2 set, protecting circuit correct – 1Amps & 5Amps sets, records history- 5Nos, Min 6 Analog out put, with following protections feeder protection 50/ 51N (3 Phase current), 50/ 51N (Earth Over current), 67 P (3 Phase directional Over current), 6/N (Earth fault directional over current), 51V (Voltage controlled over current) 37 (3 phase under current), 46(Negative phase sequence over current), 59N (Residual over voltage), 49 (Thermal over load), 79(Auto reclose), 50BF( Circuit breaker failure detection), Cold Load pickup, Inrush blocking, Relay will be on MODBUS protocol with LCD display, trip, circuit healthy, alarm, other assignable indication,Auxlary suppy : 110V DC, Schnieder make P-VAP57, P127 or ABB make REF615 or SIEMENS make 7SR10

M&L for disconnecting carefully electrical connection from both HT/ LT (primary & secondary) sides of the transformer, keeping them at safe side and taking out the transformer indoor/ outdoor type of capacity from 500 KVA to 750 KVA , 11 KV/ 0.433 KV, step down any make for carrying out complete overhauling which shall comprise of the following:-

a) opening top cover of the transformer by unscrewing nuts, bolts, washers etc. including disconnecting core assembly from HT/ LT bushing and lifting the same gently and taking out from the shell (container/ body) of the transformer.

b) M&L for draining out transformer oil from the above said transformer in the suitable capacity of container /drums and keeping it in safe custody for reuse.

c) M&L for cleaning the transformer body from inside, removing deposited dirt/ sludge/ foreign particles etc. from the bottom/ body of the transformer and drying up the shell from inside before refilling of the transformer oil.

d) M&L for cleaning and washing thoroughly core and windings of the transformer by hosing down with clean dry oil, removing deposited dirt/sludge/foreign particles from the windings/ core, thorough inspection of windings, providing insulations to leads and terminals, heating/ drying/ baking complete carefully and thoroughly inside the heating chamber at suitable temperature to obtain required value of insulation resistance etc. all as directed by Engr-in- charge.

e) Lifting and refixing core assembly inside the transformer shell gently and carefully, connecting primary/ secondary/ Neutral connections to the bushings assembly, fixing of tap change over including tightening of nuts, bolts, washers of the core to reduce humming noise all as directed.

f) Refilling the filtered transformer oil in the shell of transformer complete.

g) Refixing the top cover including replacement of cork sheet/ gasket, tightening of nuts/ bolts/ washers etc. and replacement of breather with silica gel crystal type all as directed by Engr-in charge

h) Lifting/ shifting to the place from where removed and re-installing the transformer including connecting primary/ secondary/ neutral connections etc. all as directed by Engr-in-Charge.

Note:-(i) Any damage to insulators/ bushes/ windings etc. while in the custody of the contractor shall be made good at no extra cost to Department. The serviceability of the transformer shall be checked and confirmed by the contractor before taking into his custody. (ii) M&L for rewinding/ re-insulation of HT/ LT (primary/ secondary) coils, bushes, studs, Transformer oil,cable box, replacement of buchholtz relay/ MOG if any etc will be measured and paid separately.

M&L for preparation of old painted surfaces of transformers with coarse cloth/ brush and painting throughout externally on exposed surfaces with two coats of smoke grey colour synthetic enamel paint including complete including one coat of white wash for base foundation all as specified and directed by Engineer-in-charge for the following capacity in-door/ out-door type transformer:-

Capacity upto 160 KVA

Capacity from 161 to 315 KVA

Capacity from 316 to 500 KVA

Capacity from 501 to 800 KVA

M&L for replacement of silica gel in breather of transformers for all as directed.

Taking down HT VCB of any make/ capacity, 11 KV, 630A for servicing/ repairs, replacement of defective/ worn out components and refixing back including testing comprising the following:-

(i) Disconneted the vacuum interrupter assembly from VCB panel along with all connections, adjustment of contact gap as required.

(ii) Disconnected socket contacts, cleaning and adjustment of gap,replacement of rings etc.

(iii) Checking the breaker bushing of bus bar and circuit side,inspection/ servicing of internal surface for any arcing/ tracks.

(iv) Checking the epoxy body completely for any cracks, any sign of arcs/ tracks, cleaning thoroughly with CTC including applying Bectrol red varnish.

(v) Checking the drive insulator assembly and inspect for chocking/tracks/ arcing.

(vi) Taking the IR value of all components,confirm satisfactory results before refixing in VCB panel.

Dismantling the spring charging mechanism of the VCB, checking the entire mechanism for any worn/ crack/ bent/ block/ loose parts etc. for the following:-

(i) Checking the condition of the spring charging motor along with gear box including servicing the motor & replacement of motor bearings if required.

(ii) Checking/ servicing of ratchet wheel assembly, driving and charging parts.

(iii) Checking the auxiliary switch, its contacts for proper functional operation.

(iv) Checking & servicing of raising/ lowering mechanism and its locking system for proper functioning.

(v) Checking & servicing of shutter assembly for its automatic opening/closing.

Note:-The items like nuts, bolts, spring washers, petroleum jelly, CTC etc required to put the breaker in serviceable condition shall be supplied by the contractor and rate shall be deemed to be included in the unit rate quoted.

Dismantling Existing earthing and providing new maintenance free Chemical earthing complete with 40mm x 3000mm Advance Chemical Earthing Pipe with (Strip in Pipe Technology) with 50 Kgs of Back Fill Compound buried directly in ground (Rocky soil) with earth pit not less than 2.5 Mtr deep below the normal ground level with top edge of plate not less than1.5 Mtr below normal GL connected to GI strip 25x6mm as earth strip by means of SS bolts,nuts,check nuts and washers all as per IS 3043-1987 all as specified or indicated including testing on completion and as directed. The earth resistance shall be measured using fall of potential method as per para 37 of IS:3043 & Combined resistance should be less than 1 Ohms. (Note:-The unit rate shall be deemed to include for Excavation & earth work in any type of soil,PCC (1:3:6) type Chamber,RCC 1:2:4 type B-1 cover 50 mm thick reinforced with 8mm dia CTD bars@75mm c/c both ways ,MS handle 12mm dia and funnel.

M&L for detecting HT/LT UG cable faults located in any stretch / depth with cable fault locator consisting of microprocessor based, identification instrument, cable tracer for exact location of under ground cable routes. Notes:- The rate quoted deemed to be inclusive of rental charges for T&P like entire cable fault locating instrument, charges for operator and transportation etc complete.

M&L for fixing in repair power pack DC for auxiliary power supply to operate closing & tripping coils, protection relay circuits and other indication lamps for 11 KV HT VCB panel suitable to operate the control circuit on Input supply 110 V AC + 10% to -30% 50 HZ or 230 V AC +10% to -30% 50 HZ to give an output supply of 110 V DC including dismantling old one. Make:- GE/LEGRAND/ PROTECH Note : The rate quoted deemed to be inclusive of suitable stranded copper conductor cable from power pack to HT panel complete

M&L for re-windings of HT distribution transformers of any capacity/ size/ type by strip opening of HT coils (i.e. Primary coils) from core assembly safely, unwinding the HT (i.e. Primary coils) complete, removing the old defective insulation paper, rewindingwith new copper wire of same gauge and existing size together with new DPC insulation to the copper conductor, varnishing of the windings including heating/ drying/ backing complete carefully and thoroughly inside the heating chamber at suitable temperature to obtain required value of insulation resistance etc. all as directed by Engr-in- charge.

M&L for re-insulating of LT strip of transformers of any capacity/ type by insulating with copper strip as per same gauge and existing size together with new insulated materials/ bracings before placing in to the transformer and assembling the coil with new insulation and fitting the coils in the chamber, testing and commissioning the transformer complete all as directed.

Supply and topping up of transformer oil with di-electric strength not less than 50 KV in to the conservator tank/ body tank of the transformer/ OCB/ FRMUs etc at various locations complete all as directed by the Engineer-in-Charge. [Make: Poweroil/ Transol/ Sabitha Chemicals]

Filtration of transformer oil of transformers/ FRMUs installed at various locations to achieve di-electric strength not less than 50 KV at 2.5mm gap as per relevant IS with portable filtration plant, testing of the oil for the di-electric strength before filtration and after filtration complete all as directed by the Engineer-in-Charge.

SRI SRK ENGINEERS

M/s NATIONAL ENGINEERING CONSTRUCTIONS CO

R AND A ASSOCIATES ENGINEERS CONTRACTORS

SREE DURGA INFOTECH

JAI ENTERPRISES

M.V.K.ENTERPRISES