SPECIAL REPAIR TO LIGHTENING PROTECTION FOR CERTAIN OTM ACCN AT AFS SURYALANKA

Taking down the old aluminium/GI strip without damaging the existing surface as specified and directd by engr-in-charge.

S&F in repair earth continuity conductor fixed to wall or batten or recess or cheses or buried in ground or drawn in conduit pipe or fixed to poles or any other indicated situation as required of size copper strip of size 20 x 3.15 mm with saddles and fixing screws etc

Test point terminal block made of gun metal or phosphorous bronze, size 75 x 75 x 25mm drilled and screwed including 3 nos `8mm dia, 25 mm long hexagonal head screw all as specified and directed.

M&L for Brazing of size 40mmx25mmx5mm in copper strip of size 25x3mm at the joint of strip through copper rod of proper size and combination of oxygen acetylene gas cylinder.Joint must be able to withstand high tensile strength and properly done without any defect or without any crack all as specified and directed. Note :- (1) If any crack found in the brazing contractor will do brazing free of cost again.

Earthing complete with galvanised steel earth plate electrode, 60cmx60cmx6mm thick, buried directly in ground (earth pit not less than 2.25 metres deep below ground level) with top edge of the plate not less than 1.5 metres below normal ground level, connected to galvanised earth lead but using galvanised iron strip 35x6mm as earthling lead by means of bolts, nuts, check nuts and washers of galvanised iron or steel incl GI pipe 40 mm light grade for protection of earthing lead and GI pipe 20mm medium grade for watering incl funnel all as shown in electrical plate No. 5 connected to earthing test point all as specified or indicated including testing on completion. The following quantity of earthing material is required:- (a) Charcoal-100 Kg (b) Salt-60 Kg (c) Magnesium suplhate crystal-100 Kg