REPAIR MAINT OF EARTHING PITS LIGHTENING PROTECTION AND ALLIED WORKS AT AF STATION PURNEA UNDER GE AF PURNEA

Amount

Taking down old U/S earth plate electrode and PCC earth pit cover, and all relevent item of earthing buried in ground of any type and size all as specified and directed by Engr- in- Charge.

Taking down old U/S earth continuity earthing lead removed from wall on batten or recess or buried in ground or conduit/ pipe etc of any type and size all as specified and directed by Engr- in- Charge.

Taking down old U/S terminal block made of gun metal/ MS of any size and type all as specified and directed by Engr- in- Charge.

Taking down old U/S Air Termination , single pointed Aluminium/ copper rod of any type and size all as specified and directed by Engr- in- Charge.

M&L for Earthing complete with copper earth plate electrode of size 600 x 600 x 3.15mm thick buried directly in ground with earth pit not less than 2.25 meter deep below ground level with top edge of plate not less than 1.5 meter below normal ground level connected to copper strip of size 20 x 3mm earth lead by means brazing after fixing of nuts, bolts, check nuts, washers of galvanised iron steel, protected by galvanized iron pipe 40mm bore (Medium grade) all as directed including cement concrete (1:3:6) type C-1 earth pit with precast RCC (1:1.5:3) type A-1 cover slab of size 42 x 42 x 10cm thick reinforced with 8mm dia TMT bars @ 15 cm c/c both ways with 10mm dia mild steel round bar of 30 cm long, bent to shape as lifting handle, funnel, wire mesh, 20 mm bore galvanized iron pipe (medium grade) for watering, earth testing point, charcoal or coke and salt in alternate layers with necessary earth work in soft/loose soil complete all as shown in electrical plate No 3 of SSR Part I including testing on completion complete all complete as specified and directed. Note :- If the desired earth resistance is not found, earthing shall be redone by the contractor at no extra cost to the department.

M&L for in replacement earth continuty conductor or main earthing lead fixed to wall on batten or recess or burried in ground or drawn in conduit/ pipe or fixed to poles or any other indicated situation for loop earthig etc as required with copper strip of 20 x 3 mm with saddle & fixing screw etc for roof conductor and down conductor above ground.

M&L for in replacement test terminal block made of gun metal for phosphours bronze size 75x 75x25 mm drilled and screwed including 3 Nos 8 mm dia 25 mm long hex. Head screw all as specified and directed by Engr- in- Charge.

S&F Air termination , single pointed copper rod 12mm dia 300 long as directed by Engr- in-Charge.

S&F in replacement GI tubing (Light grade) 32 mm bore 1.5 Mtrs long fixed on roof vetically by means of base plate clamp nut-bolt 2 mm stay wire including PCC foundation complete all as specified and directed by Engr- in-Charge.

S&F 40mm dia steel tubes (light grade) galvanised with fittings, laid in trenches/wall for protection of underground earth strip when crossing the road/fixing on wall as in repair complete all as specified and directed.

M&L for fabrication of display board for earth pit nos. location and periodical test results for power circuit earthing, machinary earthing, lightening conductor earthing, made of GI shett 4.0 mm thick, rectangular welding on 12 mm dia rod of minimum height from ground level 45 cm including fixing in PCC 1:2:4 with 20cm X 20cm X 10cm grade aggregate foundation to be carried out at different location. dimension of board shall be 30 cm X 25 cm X. The instruction shall be written black painted board in white letters not less than 2" size for all type of boards complete all as specified and directed by the Engineer-in-charge.

Supply & Installation of Advance encapsulated compound based CPRI tested maintenance free, pipe-in-pipe technology upgraded (Zinc & Alloy Coated), ZINC COATED( 80-100)microns with pure Zinc (99.9%) & ALLOY COATING (200-250)microns. Earthing System confirming IS 3034. The outer and inner pipe should be 76.2 mm & 41.9 mm 3mtrs Length, Zinc coated with additional special Alloy coating 300mm on the topside for additional corrosion protection of the Terminal. The annular space between the pipes being filled up with COMPACT FILL(CF) (Crystalline Conductive Compound). The COMPACT FILL (CF) mixture which is machine pressed in the pipes should not disintegrate or collapse when outer pipe corrodes. The inner pipe should be extended with terminals for connectivity The job includes digging the pits and refilling the same by Conductolite Back Fill compound (Ground Enhancer)-02begs, the BFC should be eco friendly it should not contain environmentally hazardous material/metal having RoHS Certification from NABL accredited lab. Good earth is to be arranged to fill the excavated pits by mixing the 2 bags electrodite BFC in soil. including FRP (Fiber reinforced plastic) light weight, high mechanical strength, chemical resistance with detachable easy locking lid of size 250mm X 250mm of thickness 2mm,The eart pit has been excavated 1mx1mx3m depth and filled by black cotton or good normal soil mixed with 2 beg of BFC Electrodite complete all as specified and directed. Note:Earth strip for connection has been measured and paid seprately.The earthing value should be less than 2 Ohms for single earth. Make: Ashlok Model ASEEL-39/19 3m length(zc & ac) or equivalent.

Supply & Installation of Advance encapsulated compound based CPRI tested maintenance free, pipe in-pipe technology upgraded (Zinc & Alloy Coated), ZINC COATED (80-100) microns with pure Zinc(99.9%) & ALLOY COATING (200-250)microns. Earthing System confirming IS 3034.The outer and inner pipe should be 48.3mm & 26.4mm 3 Length, Zinc coated with additional special Alloy coating 300mm on the topside for additional protection of the Terminal. The annular space between the pipes being filled up with COMPACT FILL(CF) (Crystalline Conductive Compound). The COMPACT FILL (CF) mixture which is machine pressed inthe pipes should not disintegrate or collapse when outer pipe corrodes. The inner pipe should be extended with terminals for connectivity, The job includes digging the pits and refilling the same by Electrodite & Conductolite Back Fill compound (Ground Enhancer), the BFC should be eco friendly it should not contain environmentally hazardous material/metal having ROHS Certification from NABL accredited lab. The earth pit should be provided with a FRP earth pit cover for protection and safe guard of terminals. the earth pit has been excavated 1mx1mx3m and filled with, G00D EARTH ie Black cotton or moistures normal soil is to be arranged to fill the excavated pits by mixing the arranged soil with BFC 2 Electrodite & 2 bags Conductolite BFC for installation of earth Electrode. As the earth electrode is the main component of the Earthing system which is in direct contact with the ground and thus provides a means of releasing or collecting earth leakage currents. The material should have good electrical conductivity & anti corrosion property in wide range of soil conditions. Note:Earth strip for connection has been measured and paid seprately.The earthing value should be less than 2 Ohms for single earth Make “ASHLOK”Model-ASEEL-19/3M length (ZC & AC) (All the above given dimensions may vary ± 1 MM) OR Make “INDELEC”, “MACMATE”

Supply and fix Baron back fill compound(ELECTRODITE)25KG a bag for filling in exixting earthing complete all as specified and as directed

Supply and fix Baron back fill compound(CONDUCTOLITE)25KG a bag for filling in exixting earthing complete all as specified and as directed

Supply and fix Copper bonded 17.2mm 250 Microns steel rods with low carbon high tensile (UL Specified) CPRI Tested 3 Mtr length with prewired or seprate clamp complete all as specified and as directed

labour only for repair of old earthing using items sr no 14,15,and 16 for improvement for eartnig resistance value,item no 14,15 and 16 has been measured and paid as per ground execution for required earth resistance value inculiding taking down of old earthing and re filling of all required material,black cotton soil etc all as specified and as directed.

M/s.Keshab Chandra Ghosh