PROVISION OF EARTHING PITS AT EDPW OF AFRO AT CAMERO COMPLEX AND PROVISION OF VCB TROLLEY AT MAIN INCOMING SUB STATION A AT HQ WAC, SUBROTO PARK

M&L for Conductive Concrete Earth Grid of multiple interconnected Earth Electrodes to achieve the earth resistance value of less than < 1 Ω. The excavation is to be carried out in any type of soil including hard rock. The necessary soil treatment to be carried out to achieve the desire result. The tentaive specification are as under:- (i) Earth Electrodes: Metal conductor - Copper bonded MS rod dia 17.2 mm (+/-.5mm), Length 3 meter with conductive concrete embedding with bore dia 100 mm, Length 3meter of earth electrode. (ii) All earth electrodes should be installed in specially treated soil earth pits of size 1.5 meter x 1.5 meter x 3 meters each (Minimum three or more Earth Pits) shall be prepared by removing high resistivity soil/ rock. The earth pits having copper strip 25mm X 3mm size and provided at the bottom of the pit 7 Strips of 1.2m in one side and 7 strips of 1.2m in other side total 14 Nos of copper strips of 1.2mtr length and the grid of copper strip to be emboded in 100mm thick conductive concrete to be filled with fresh low resistivity sieved soil and compacted with water. The soil treatment chemical should be non corrosive, highly conductive & there shall not be need of water for electrical conductivity. (iii) Interconnected Strip: All the multiple Earth Electrodes will be horizontally interconnected with metal conductor - Copper strip flat size : 25mm x 3 mm & conductive concrete embedding size : 75 mm². (iv) Test Link : Test links - Copper strip flat size : 50 mm x 6 mm x 200 mm shall be provided, at any one of the four Earth Electrodes of the grid for connection between earth grid pit and application. (v) Pit Cover : RCC pit cover & frame shall be provided at all Earth Electrode (with test links). Note :- (i) The vendor to provide CPRI test report for current greater than 20 KA with peak at 38 KA, The report shall not be more then10 year old from the date of tender. (ii) The product should be ROHS compliance. (iii) The testing of earthing to be carried out every year for 5 years after completion or work. (iv) The contractor to submit unconditional guarantee for 10 years for replacement & earthing if results are not satisfactory. (v) The earthing to be carried out by OEM only. The MOU in this respect to be submitted by contractor while quoting the contract. (vi) Bidder shall produce certificate for resistivity of conductive concrete. (vii) Fault Current Tested at 35 KA Peak With 17.2mm copper bonded rod of 3mtr length embedded With Conductive Concrete. (viii) On completion of work Engineer in charge will check the earth resistance in presence of user, Contractor will re-do the earth if earth resistance value is more than 1 Ohm. (ix) All connecting strips would be of copper of size 20x3 mm and cost of the same is included in the rate quoted, upto test point. (x) Test certificate of earthing material for ROHS compliance, Resistivity value and fault current test for electrode from certified NABL laboratory shall be submitted .

S&F Earth continuity conductor or main earthing lead complete with insulator, saddles, fixing screws fixed to wall on batten or recess or chases or burried in ground or drawn in conduit/pipe or fixed to poles or any other indicated situation for loop earthing etc. as required 20x3mm copper strip complete all as specified and directed.

Supply installed test and commissioning of trolley for 11 KV 800 Amps Horizontal drawout type Vacuum Circit breaker comprising of :- (a) Vacuum Interupter (b) Vacuum Interupter housing (c) Finger Contact (d) Motor/Manual spring charging mechanism 230 Volt AC (e) Closing & Tripping Coil suitable for 24 V DC (f) 6 No and 6 NC Auxillary Switch (g) Mechanical On/Off indication (h) Mechanical Spring Charge/Discharge (j) Mechancial Operating Counter (k) 24 Pin Isolating Plug Note : The VCB trolley should be suitable for existing VCB's of make ITE Gurugram