PROVISION OF CONSTRUCTION OF CHEMICAL EARTHING PITS AT SHIBPUR (REVENUE WORK) UNDER GE (S) DIGLIPUR

Amount

M&L for chemical earthing complete with copper earth plate of size 900 mm x 600 mm x 5 mm thick buried in ground vertically to a depth not less than 2.50 mtr below normal ground level with top edge of plate at a depth not less than 1.50 mtr below normal ground level with a bottom layer MG SO4 of 150 mm thick, earth plate surrounded with graphite powder, vegetable soil mixture mixed with bentonite in equal proportion, charcoal and common salt in equal proportion around and 150 mm above the plate and 150 mm thick MG SO4 as top layer and the remaining portion filled with compacted black cotton / loomy soil and connected with copper strip 32 mm x 6 mm duly brazed and by means of bolts, nuts and washers up to 7.50 mtr length and connected to earthing test point, GI pipe light grade 40 mm bore for earth lead protection and GI pipe medium grade 20 mm bore for watering with funnel and wire mesh all as shown in electrical plate No. 3 of MES SSR Part-I 2009 and specified and testing on completion including provision of earth pit with necessary earth work, RCC 1:2:4 cover slab 50 mm thick with reinforcement of 8 mm dia TMT bars @ 100 mm c/c both directions and PCC chamber with PCC 1:3:6 type C2 including excavation and earth work, disposal of surplus soil to a distance not exceeding 50 mtr complete all as specified and as directed by Engineer-in-charge. Notes:- (i) The length of the copper strip beyond 7.50 mtr shall be measured and paid separately. (ii) All joint of copper strip shall be of brazing only. (iii) Earthing is to be done in front of the Engineer-in-charge. (iv) Test result of earthing to be submitted by the contractor for all earthing pits. (v) The contractor shall give guarantee for maintenance earth resistance of less than 1 Ohm for a period of 05 (Five) years after certified date of completion and shall deposit security deposit of Rs. 2,000/- per earthing pit for a period of five years. (vi) Failing to maintain earthing pit result less than 1 Ohm, new earthing pit to be provided by the contractor without any extra cost to department. (vii) Necessary earth work excavation in any type of strata, returning filling and making good the surrounding area complete.

M&L for earth continuty conductor or main earthing lead fixed to wall on batten or recess or chases or buired in ground or drawn in conduct/pipe or fixed to poles or any other indicated situation for loop earthing etc. as required with 32x6 mm copper strip complete all as specified and as directed by Engineer-in-charge

M & L for test point terminal block made of gun metal or phosphorus bronze size 75 mm x 75 mm x 25 mm drilled and screwed including 3 nos of 8mm dia 25mm long hexagonal head screw complete all as specified and as directed by Engineer-in-charge

SKY GROUP

ASHOK BISWAS