SPECIAL REPAIR / REPLACEMENT OF CERTAIN EARTHING AND LIGHTENING INFRASTRUCTURE AND PROVN OF LIGHTENING PROTECTION SYSTEM WITH EARTHING PITS AT NEWLY INDUCTED HUT AT AF STN BAREILLY UNDER GE(AF) BAREILLY

Taking out old earthing Infra with test point and GI pipe compete all as specified.

M&Lfor earthing comprising of copper earth plate electrode 600 mm X 600 mm X 3.15 mm thick buried directly in ground (earth pit not less than 2.25 m below ground level) with top edge of earth plate not less than 1.50 mtr below normal ground level and connected to copper earth strip of size 20mm X 3mm by means of nut-bolts, check nuts and washers of galvanised iron or steel all as shown on Electrical plate No. 3 of MES schedule Part–I (Specifications) and connected to main switch board / main DBs / earthing test point including all necessary excavation and earth work in any type of soil, adequate quantity of charcoal dust and common salt all around the earth plate in alternate layers of minimum 150 mm (compacted thickness) in all directions with and including GI watering pipe 20 mm bore, medium grade, with funnel made out of 0.63 mm thick GI sheet, GI protection pipe light grade 40 mm bore complete all as specified and directed. Note: The earth resistance value should be less than 3 ohm failing which the contractor shall re-do the earthing without any extra cost.

M&L for chemical earthing complete with Copper earth plate electrode 900mmx 600mm x 5 mm thick buried directly in ground vertically to depth not less than 3.00 mtr below ground level with top edge of earth plate at a depth not less than 2.25 mtr below normal ground level and connected to and including copper strip of size 32x6mm as earth lead up to 7.5 mtr long fixed by means of bolts, nuts, check nuts and washers or brazing etc. of galvanised iron or steel including provn of GI protection pipe light grade of 40mm bore and connected to earth strip earthing test point all as shown in Electrical plate No.5 of SSR Part-I all as specified and testing on completion including necessary excavation & earthwork in any type of soil, cement concrete (1:3:6) type C-1 in chamber, RCC precast slab 50mm thick in cement concrete (1:2:4) type B-1 reinforced with welded steel wire fabric XPM of weight not less than 4 kgs/sqm with frame, funnel with GI watering pipe of 15mm bore medium grade, wire mesh and lugs, test point including salt (150Kgs), Coal dust(100Kgs) & Magnesium sulphate (150Kgs) including refilling of earth pit with cultivated soil and removal of surplus soil upto 50mtrs apart complete all as specified. Note: The earth resistance value should be less than 1 ohm failing which the contractor shall be re-do the earthing without any extra cost.

M&L for test point terminal block made of gun metal or phosphorus bronze size (75x75x25)mm drilled and screwed including 3 nos. 8mm dia 25mm long hex head screws for holding the bronze plate including fastening/ bolting the roof down conductor and earth electrode over the bronze plate with copper bolts & nuts of suitable size complete all as specified and as directed.

M&L for earth continuity conductor with GI strip of size 25mm x 4 mm burried in ground, fixed to wall, or any other location indicated situation for loop earthing and the like upto test point on necesarry insulators and fastning screws, rawl plugs including dismantling of existing strip all as specified. NOTE : The joints of each lead strip shall be welded / brazed and the cost of brazing / welding shall deemed to be included in the quoted rate of this item.

M&L for earthing comprising of copper earth plate electrode 600 mm X 600 mm X 3.15 mm thick buried directly in ground (earth pit not less than 2.25 m below ground level) with top edge of earth plate not less than 1.50 m below normal ground level and connected to copper earthing strip of size 20 mm X 3 mm by means of nut-bolts, check nuts and washers of galvanised iron or steel all as shown on Electrical plate No.3 of MES schedule Part–I (Specifications) including excavation and earth work in any type of soil including disposal of soil, providing alternate layers of charcol and common salt, construction of PCC earth chamber in 1:3:6 mix type C-1, 40 mm thick RCC pit cover in concrete 1:2:4 type B-1 reinforced with 8 mm dia TMT bars both ways with lift hook made out of 8 mm dia round bar,watering arrangement. Note : Main earth lead beyond 7.5 meter shall be measured and paid seperatly.

M&L for earth continuity conductor or main earthing lead fixed to wall on batten or recess or chases or buried in ground or drawn in conduit/pipe or fixed to poles or any other indicated situation with loop earthing copper strip of size 20mm x 3 mm all as specifed.

M&L for 25 mm bore GI tubing, medium grade, galvanized with and including all fittings as required at site, laid in trenches, on surface, under floor or fixed to wall complete all as specified.

M&L for aluminium strip 25mmx3mm as in earth continuity conductor or main earthing lead burries in ground, fixed to wall or any other indicated situation for loop earthing and the like up to test point on necessary insulators and fastening screws, rawl plugs complete all as specified.

M&L for single pointed air termination aluminum rod of 12 mm dia and 300 mm long including 20 mm size air terminal base / ridge saddle made of gun metal with and including fixing arrangment on the ridge of RCC roof / on pole as required all as specified.