SPECIAL REPAIR/REPLACEMENT OF EARTHING PITS AND LIGHTNING ARRESTOR FOR (P-01) BUILDING AT NTS(K).

Supply and fix in replacement of air termination, single pointed, copper rod 12 mm dia and 300 mm long for lightning conductors complete as specified and directed..

Supply and fix in replacement of copper strip 20 x 3 mm with saddles and fixing screws etc for roof conductors and down conductors above ground complete as specified and directed.

Supply and fix in replacement of test point terminal block made of gun metal or phosphorus bronze size 75x75x25 mm drilled and screwed including 3 numbers 8 mm dia 25mm long hexagonal head screw complete as specified and directed.

Material and labour earthing complete with copper earth plate electrode of size 600mmX600mmx3.15 mm thick buried directly in ground vertically to a depth not less than 2.25 metres below the normal ground level with top edge of the plate not less than 1.5m below normal GL and connected to copper strip of size 20 x 3 mm size by means of bolts, nuts, check nuts and washers of galvanized iron steel all as shown in Electrical Plate No.3 connecting to earthing test point, including necessary earth work in any type of soil, PCC earth chamber made in PCC 1:3:6 type C1 (using 20mm graded aggregate), common salt, charcoal with 150 mm thickness all sides of plate, CI funnel,CI earth pit cover including necessary hinges on one side, including necessry test on completion, all as specified and as directed. Note : (a)The unit rate shall also include for excavation, earth work in hard/dense soil PCC (1:3:6) type C1 pit of size 300x300x300 mm, CI cover slab of 10 mm thick with marking Earthing, GI funnel with 20 mm dia watering pipe, wire mesh, 40 mm dia medium grade GI protection pipe for earth lead etc., complete. (b) Earth resistance should be less than 1-2 Ohm on testing after completion.

Material and labour for chemical earthing complete with copper earth plate electrode of size 90 cm X 60 cm x 5 mm thick buried directly in ground vertically to a depth not less than 3.25 metres below the normal ground level with top edge of the plate not less than 2.35 m below normal GL and connected to copper strip of size 32 x 6 mm size by means of bolts, nuts, check nuts and washers of galvanized iron steel all as shown in Electrical Plate No.3 connecting to earthing test point, including necessary earth work in any type of soil, PCC earth chamber made in PCC 1:3:6 type C1 (using 20mm graded aggregate), common salt, earthing compound (chemical type) bentonite/graphite based with minimum thickness of 150 mm on all sides of plates, CI funnel, CI earth pit cover including necessary hinges on one side, including necessry test on completion, complete as specified and directed. Note :- (a) The unit rate shall also include for excavation, earth work in hard/dense soil PCC (1:3:6) type C1 pit of size 300x300x300 mm, heavy duty CI cover with 10 mm thick marked earth, GI funnel with 100 mm dia with wire mesh and watering pipe 20mm dia medium grade GI protection pipe for earth lead etc., complete. (b) Earth resistance should be less than 1 Ohm on testing after completion.

Material and labour for taking down of old earthing completely, and level the ground including removing of waste mtrl from site complete as specified and directed.