PROVISION OF EARTHING PITS(PHASE-II) AT VARIOUS LOCATIONS,SPECIAL REPAIR/REPLACEMENT TO EARTHING PITS AT VARIOUS LOCATIONS AND SPECIAL REPAIRS TO WSA EARTHING INFRASTRUCTURE AT AFS TEZPUR UNDER GE AF TEZPUR.

Amount

Taking down carefully existing damaged/unserviceable Copper/GI strip and GI wire as in earth continuity conductor or main earthing leadfixed to wall on batten or recess or chases or buried in ground or drawn in conduit/pipe or fixed to poles or any other situation of any size and type, complete all as directed.

Taking down carefully existing unserviceable test point terminal block of any size and type complete all as specified and as directed.

Excavating in trenches, n exc 1.5 m wide and n exc 1.5 m in depth; for foundation, etc. or for shafts, wells, cesspits, manholes, pier holes, etc. n exc 10 sq m on plan and n exc 1.5 m in depth and getting out in soft/loose soil ,complete all as specified and directed.

Returning filling in soft/loose soil, including, spreading levelling watering and well ramming in layers not exc. 25 cm complete all as specified and directed.

Removing excavated soils to a distance not exceeding 50 Metres and depositing where directed at a level n. exc. 1.5 M above the starting point complete all asspecified and directed.

Materials and Labour for, test point terminal block made of gun metal or phosphorus bronze size 75x75x25mm drilled and screwed including 3 nos. 8mm dia 25mm long hex. head screw,complete all as specified and directed.

Materials and Labour for, copper strip 20 x 3.15mm with saddles and fixing screws etc.for roof conductors and down conductors above ground,complete all as specified and directed.

Materials and Labour for,copper strip 20 x 3.15mm buried in ground, complete all as specified and directed. Note:- Earthwork will be measured and paid seperately.

Supply and Fix in repairs,digital lightning strike counter with digital LCD display for date, time and number of discharge occurrences, degree of protection IP65, detection up to 100 kA (10/350 μs),threshold current (8/20 μs) (ITC) 1kA, Max. discharge current (10/350 μs) (Imcw) 100kA,operating temperature range (TU) (-) 20°C to (+) 60°C,with features for number of recorded occurences upto 999, complete all as specified and directed. [Cat No.DLSC 100 IP 65 Part No. 599 100 of Make 'DEHN'(www.dehn-international.com) or equivalent Model of Make 'INGESCO' (www.ingesco.com) /'LPS (www.lpsfr.com)'/OBO(www.obo.global)]

Materials and Labour for maintenance free chemical earthing system using 04 (Four) spikes 17.2mm dia, 3000mm long high tensile low carbon steel circular rod, molecularly bonded with copper on outer surface (minimum copper bonding thickness of 250 microns) meeting the requirements of Under Writers Laboratories (UL) 467-2007 or latest with 250mm long copper strips of size 50X3 mm, exothermally welded on top of electrode complete including augering (boring) 100-125mm dia holes as required for electrodes in any type of soil and back filling with earth enhancing chemical compound as per IEEE 80 2000 Clause 14.5b, conforming to IEC 62561-7,minimum quantity of compound used 40 Kg per electrode and including back filling of pit and interconnection with soil mixed with earth enhancing chemical compound as per IEEE 80 2000 Clause 14.5b, conforming to IEC 62561-7,min quantity of compound used 62 Kg, thus minimum total qty 222 Kg per set,conforming to IEEE/BS standards including pit covers light weight made out of high quality polymer with lid made of HDG steel, including nessary testings and commissioning,complete all as specified and as directed. Notes:- (i) The work of earthing shall be carried out by authorised trained rep of OEM. (ii) The acceptable earth resistance at earth busbar/ test point shall be as per users requirement as desired by Engr-in-Charge but it should be below 01 Ohm. At certain locations, it may not be possible to achieve desired earth resistance due to higher soil resistivity,in such cases, provision of loop earthing consisting of additional earth electrode pits shall be done. The distance between two successive earth electrodes shall not be less than 3 metres. (iii) The procedure mentioned here-in-before for one earth pit shall be repeated for other earth pits. (iv) Loop conductor for interconnection of electrodes will be measured and paid seperately . (v) The quoted rate shall also be included the following elements: (a) Complete earthwork including drilling holes for electrodes.(b) Earhing electrode-04(Four) Nos Only (c) Backfilling carbon based ground enhancing compound (GEC). (d) Pit cover light weight made out of high quality polymer with lid made of HDG steel for each pit. (e) Soil suitable for agricultural purpose required for each pit (f) Copper strip as earthing lead of size 50mmx3mm, 250 mm long only, beyond 250mm, other size will be measured and paid for separately under respective item(s) in this BOQ. (g) All Labour and T&P required including testing of earth network. (vi) Testing for earth resistance shall be carried out in presence of GE and Engr-in-Charge. (vii) Taking out existing unserviceable earthing system complete. (viii) Original purchase vouchers for copper rod and back fill compound and manufacturer test certificate of entire quantity shall be produced by the contractor before commencement of work. (ix) The Earthing shall be carried out with Soil suitable for Agricultural purpose.

Materials and Labour for maintenance free chemical earthing system using 08 (Eight) spikes 17.2mm dia, 3000mm long high tensile low carbon steel circular rod, molecularly bonded with copper on outer surface (minimum copper bonding thickness of 250 microns) meeting the requirements of Under Writers Laboratories (UL) 467-2007 or latest with 250mm long copper strips of size 50X3 mm, exothermally welded on top of electrode complete including augering (boring) 100-125mm dia holes as required for electrodes in any type of soil and back filling with earth enhancing chemical compound as per IEEE 80 2000 Clause 14.5b, conforming to IEC 62561-7,minimum quantity of compound used 40 Kg and including back filling of pit and interconnection with soil mixed with earth enhancing chemical compound as per IEEE 80 2000 Clause 14.5b, conforming to IEC 62561-7,min quantity of compound used 124 Kg, thus minimum total qty 444 Kg per set, conforming to IEEE/BS standards including pit covers light weight made out of high quality polymer with lid made of HDG steel, including nessary testings and commissioning, complete all as specified and as directed. Notes:- (i) The work of earthing shall be carried out by authorised trained rep of OEM. (ii) The acceptable earth resistance at earth busbar/ test point shall be as per users requirement as desired by Engr-in-Charge but it should be below 0.5 Ohm. At certain locations, it may not be possible to achieve desired earth resistance due to higher soil resistivity,in such cases, provision of loop earthing consisting of additional earth electrode pits shall be done.The distance between two successive earth electrodes shall not be less than 3 metres. (iii) The procedure mentioned here-in-before for one earth pit shall be repeated for other earth pits. (iv) Loop conductor for interconnection of electrodes will be measured and paid seperately . (v) The quoted rate shall also be included the following elements: (a) Complete earthwork including drilling holes for electrodes.(b) Earhing electrode-08 (Eight) Nos Only (c) Backfilling carbon based ground enhancing compound (GEC). (d) Pit cover light weight made out of high quality polymer with lid made of HDG steel for each pit. (e) Soil suitable for agricultural purpose required for each pit (f) Copper strip as earthing lead of size 50mmx3mm, 250 mm long only, beyond 250mm, other size will be measured and paid for separately under respective item(s) in this BOQ. (g) All Labour and T&P required including testing of earth network. (vi) Testing for earth resistance shall be carried out in presence of GE and Engr-in-Charge. (vii) Taking out existing unserviceable earthing system complete. (viii) Original purchase vouchers for copper rod and back fill compound and manufacturer test certificate of entire quantity shall be produced by the contractor before commencement of work. (ix) The Earthing shall be carried out with Soil suitable for Agricultural purpose.

Shri A. K. Goswami

SHRI D. C. BISWAS