Provn of chemical earthing pits at various locations of AF Stn Nal under GE (AF) Nal

Amount

M&L chemical earthing complete with copper earth plate electrode 900 mm x 600 mm x 5 mm thick buried directly in ground vertically in a pit of depth not less than 3.65 metre below normal ground level with top edge of the earth plate at a depth not less than 2.90 metre below normal ground level, earth plate connected to copper strip 32 x 6 mm as earthing lead by means of running gas welding / brazing for a length of 45cm, copper strip protected by galvanized steel pipe 50 mm bore medium grade upto ground level and there after by 50 mm dia HDPE pipe upto test point (maximum upto 7.5metre from earth plate), earth plate surrounded by charcoal or coke and common salt upto 90 cm in alternate layers of 15cm each, thereover a layer of 60cm tibba sand duly compacted, thereafter 30 layer of magnesium sulphate powder (compacted thickness) and finally filing the top of pit upto ground level with tibba sand, to achieve earth resistance value less than 1 Ohm including provision of 20mm bore galvanised steel pipe 20mm bore light grade with funnel & wire mesh for watering, earth pit chamber built in cement concrete 1:3:6 type C-1 using 20mm graded stone aggregate covered with 50mm thick pre-cast cover slab of RCC 1:2:4 type B-1 duly reinforced with 8mm dia MS TMT bars @ 15cm c/c both ways, with suitable handle made of 10mm dia MS round bar, including excavation & earthwork in any type of soil / strata, removal of surplus soil to a distance not exceeding 50 metre as shown in Electrical Plate No. 3 of MES Schedule Part-I complete all as specified and directed.

Note for item No. 1.00 :- (a) Earth chamber shall be constructed minimum 0.5 metre away from earth pit. (b) On testing after completion, if the desired earth value i.e. less than 01 Ohm is not obtained, the earthing shall be re-carried out by contractor at no extra cost to the Govt. (c) The quantity of backfill material and depth of earth pit shall be added by the contractor to acheive earth resistance less than 1 ohm on completion and testing without any extra cost to Govt. (d) The rate quoted shall also include the cost of following:- (i) bronze test point of size 75mm x 75mm x 25mm. (ii) Display board of size 20cm x 15 cm made of 3mm thick MS sheet with frame and supports of angle iron 40mm x 40mm x 4mm, legs embedded in and including PCC blocks 30cm x 30cm x 15cm in 1:3:6 type C-1 incl necessary form work, earth work, painting MS work with synthetic enamel paint and marked with earth pit No. as directed. (e) The work shall be executed at different locations of AF Stn Nal. Conractor shall keep this aspect while quoting his rates. The locations of earthing is kept with AGE E/M AF Nal.

S&F Earth continuity conductor or main earthing lead 32mm x 6mm copper strip fixed to wall with porcelain insulators of suitable size with 02 No. plastic grips and screws at an interval of 30cm c/c with all fixing arrangement as required complete all as specified and directed.

S&F Earth continuity conductor or main earthing lead 32mm x 6mm copper strip drawn through and including HDPE pipe 50mm dia pressure rating 0.25Mpa as protection pipe laid under floors / ground incl necessary excavation & earth work and making up the floor to match existing finish complete all as specified and directed.

M/s Rohit Construction Co.

RAJENDER ENTERPRISES