REPAIR AND MAINTENANCE OF LIGHTENING CONDUCTOR ALONG WITH CONNECTED ITEMS FOR DBM AND IGLOO AT NAD, VAJRAKOSH AT NAVAL BASE KARWAR UNDER GE (SB) KARWAR

S&F in repairs aluminium strip 25 mm × 4 mm for roof conductors and down conductors above ground, including fixing screws, nuts, bolts and washers of suitable size, and including welding/brazing/cutting/jointing wherever required as per site conditions, complete all as specified and as directed

S&F in repairs copper strip 20 mm × 3 mm for roof conductors and down conductors above ground, including fixing screws, nuts, bolts and washers of suitable size, and including welding/brazing/cutting/jointing wherever required as per site conditions, complete all as specified and as directed.

S&F in repairs earth continuity conductor / main earthing lead as required, fixed to wall on batten or on roof/side walls of building, in recess/chases, buried in ground, drawn in conduit, fixed to poles or in any other indicated situation for loop earthing etc., GI strip 32 mm × 6 mm, complete all as specified and as directed

S&F in repairs air termination, single pointed copper rod 12 mm dia × 300 mm long, including all fixing arrangements as required at site and including connecting the same with the continuity earth strip, complete all as specified and as directed

Supply and laying in repairs PCC blocks 400 mm × 200 mm × 150 mm on roof of IGLOO/Magazine or any other indicated building/location, for placing/supporting aluminium strip, complete all as specified and as directed.

Supply and fixing in repairs of nuts and bolts (machine made) mild steel screw bolts with hexagonal/square head at one end and screwed at the other end or screwed at both ends, each screwed end fitted with washers and one hexagonal/square nut of length 5 cm to 10 cm, and dia 16 mm to 20 mm, as required at site, complete all as specified and as directed

Supply and fixing in repairs epoxy electrical insulators for insulating the GI/copper strip lightning arrester and earthing strip from the structure/ground, including fixing the insulator to existing PCC block or as required at site, complete all as specified and as directed.

M&L for chemical earthing cum maintenance-free earthing system complete with UL-467 approved copper earth plate 900 mm × 600 mm × 5 mm (purity above 99%) buried in ground vertically to a depth not less than 3.5 m below ground level with top edge of earth electrode not less than 500 mm below normal ground level, including provision of copper bus plate 200 mm × 25 mm × 6 mm for inter-connection with copper earth lead strip 32 mm × 6 mm and further connected to test point terminal block 120 mm × 120 mm × 25 mm (copper), including watering pipe (light grade) with CI/MS funnel and wire mesh, excavation/earthwork in any type of soil and removal of surplus soil to a distance not exceeding 50 m, providing continuous copper strip with joints by brazing only, including providing and packing minimum 45 kg NABL lab certified backfill compound (for single bore holes, soil mixed), providing alternate layers of conductive concrete (resistivity 0.001 Ohm) and carbon-based maintenance-free compound (20 kg bags × 5), make as per IEEE 80-2000 Clause 14.5(D), complete to achieve earth resistance below 1 Ohm and earth-to-neutral voltage less than 2 volts, including PCC chamber PCC 1:3:6 type C-1 using 20 mm graded crushed stone aggregate, with cast iron pit cover 300 mm × 300 mm including painting as per colour coding as per IS, complete all as specified and directed. Make for backfill/conductive concrete: Marconite or equivalent.

M&L for application of Earth Recharger water-soluble soil reactivation earthing compound in GEL form not less than 7 kg per earthing pit , including excavating around existing earthing pit by digging about 300 mm deep around the earth pit, mixing the Earth Recharger with 10 litres of water separately and pouring the solution slowly into the excavated portion within a period of 02 hours, leaving the solution with the earth pit for 04 hours and thereafter checking the earth resistance with calibrated and ISI marked digital earth tester of reputed make (latest model) as approved by the Engr-in-Charge/ GE, complete all as specified and as directed. Note: (i) The item shall be executed only through an authorised applicator of the approved make, duly approved by the GE.

Testing of all types of existing earthing(s) in the station by carrying out the following:- (a) Separating the earthing strip from the test point by opening nut-bolts or by cutting the earth strip as required and carrying out earth testing by a calibrated digital earth tester of renowned make (ISI marked) in presence of JE E/M / Engineer-in-Charge and representative of user. (b) Earth testing register shall be opened and values shall be noted with date and signature of representative of user. (c) If desired values are not achieved, measures such as watering of earth pit shall be carried out before retesting of the same earthing pit. In the event of not achieving desired value, earthing pit shall be repaired by digging to required level and adding salt & coal or by replacement with new earthing, as directed.

M&L in repairs for test point terminal block for earthing, made of gun metal or phosphor bronze, size 75mm × 75mm × 25mm, drilled and tapped including 3 Nos of 8 mm dia × 25 mm long hex head screws, complete all as specified & directed

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