8696 PROVN OF CHEMICAL EARTHING PITS WITH COPPER STRIPS CONNECTING UP TO LABS, TEST BENCHES AT SSC IN TECHNICAL AREA AT AF STATION BAREILLY

Amount

M&L for providing new chemical earthing comprising copper earth plate electrode 900 x 600 x 5 mm thick buried directly in ground, earth pit not less than 4.70 metres below normal ground level and complete size of pit shall be 1.60 m x 1.60 m x 5.10 metres, with top edge of the plate not less than 3.75 metres below normal ground level, earth plate surrounded from all sides by 20 cm thick salt and charcoal dust and Magnesium sulphate filling in alternate layers of 20 cm thick up to 1.8 metres height and including connected to copper strip 32 x 6 mm (up to 7.5 Metres) by means of brazing / coppers nut-bolts, earth strip protected with 65 mm bore light grade pipe from electrode up to the earth test point, 15 mm bore light grade GI watering pipe, GI funnel, wire mesh, including excavation, removal surplus soil to a distance not exc. 50 m, PCC pit in PCC (1:3:6) type C-1, using 20 mm graded stone aggregate, RCC cover 40 mm thick in RCC (1:2:4) type B-1, using 20 mm graded stone aggregate reinforced with 8 mm dia mild steel deformed bars @ 75 mm centre to centre both ways complete all as specified and directed. NOTE:- Additional Chemical compound if required on account to achieve earth resistance less than 1.00 ohm shall be deemed to be included in the unit rate of this item. On testing after completion of job, if desired earth resistance (i.e. less than one ohm) is not obtained, the earthing shall be redone by the contractor without any extra cost to Govt.

S&F GI tubes 50mm bore medium grade including all necessary GI fittings, laid in trenches/ surface/ duct/ under the floor for protection of cables/ earth strip complete all as specified and as directed.

S&F Test point terminal block made of gun metal or phosphorus bronze of 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, providing 10mm thick fibre sheet of size 15x15cm below the test point to avoid direct contact with wall including enclosing the test point with 1.6mm thick MS sheet front openable box duly painted complete all as directed by Engineer -in-Charge.

S&F 32x6mm size copper strip as in earth continuity conductor or main earthing lead buried in ground, fixed to wall or in any other situation for loop earthing and the like up to test point mounted on necessary insulators and fastening screws, rawl plugs complete all as specified and as directed.

ZAIGHAM ENTERPRISES