SPECIAL REPAIR AND REPLACEMENT OF EARTHING PITS, LIGHTENING, ARRESTORS, SPD AND ALLIED WORKS AT AF STN KALAIKUNDA

Taking out old unserviceable GI/Copper earth plate/Chemical electrode from soft and hard soil from any location as directed by Engineer -in- charge.

Material & labour for earthing complete with copper earth plate electrode 600 mm x 600 mm x 3 mm thick burried directly in ground (Earth pit not less than 4 mtr deep below ground level) with top edge of the plate not less than 3.25 mtr below ground level connected to copper strip 20 x 3 mm as earth lead by brass nut bolts washer including brazing the copper strip with copper plate as shown in electrical plate No 3 connected to earth test point including necessary excavation in hard dense soil, rocky / disintergate rock, filling charcoal and salt around the plate in layers , filling the pit with low resistivity agriculture soil free from stones, to be bring from out side defence land and mixed with Bentonite , (3 bags of 25 Kg each ), construction of inspection pit ( earth pit chamber) of brick work of size 600 x 600 x 600 mm with PCC copping of 1 :2: 4 , 12.5 mm aggregate A1 with MS sheet 2.8 mm plate cover on frame of angle iron of size 40 x 40 x 5 mm with , wire mess, funnel, test point, 40 mm dia GI protection pipe light grade and 20 mm GI peforated pipe for watering etc complete and testing on completion. The electrode and lead shall be of copper all as specified and directed by Engr-in-charge (Copper strip upto 7.5 RM will be included in the item rate and copper strip beyond 7.5 RM will be measured seperately (Note : (i) Contractor shall use low reistivity fresh agriculture soil , mixed with 3 x Bags of bentonite clay of 25 Kg each for refilling the pit to achive the desired resistance. (ii) copper strip will be laid below 60 cm from ground level and connected to test point through plinth protection (iii) Necessary cost of repair to plinth protection and connected plate and earth continuity conductor by providing 2 x brass nuts bolts and brazing of joints, bringing argiculture soil from out side defence land and cost of 3 x Bags of bentonite deemed to be included in the item rate. (iv) Contractor has to clear the side and disposed off the excavated soil from pit on completion of work. (v) Contractor has to submit test report of earthing after completing the earthing. (vi) Bentonite clay should be Conf to IS 6186: 1986

Materials and labour for earthing complete with galvanised iron earth plate electrode 600 mm x 600 mm x 6 mm thick, burried directly and preferably vertically in ground, earth pit not less than 2.25 Mtr deep below ground level with top edge of the plate not less than 1.5 m below ground level connetced with galvanised iron strip 32 x 6 mm by means of nuts, bolts, check nuts and washers made of galvanised iron or steel earthing lead to be protected by galvanised iron pipe of 40mm bore (light grade) and other end connected to earthing test point or lightening arrestor or main controlling switch as directed including providing funnel with 20mm bore galvanised iron pipe (medium grade), wire mesh, charcoal or coke and common salt in alternate layer of 15cm (compacted thickness) all round the earth electrode, concrete earth pit in PCC (1:3:6) type C-1 (with 20mm graded aggregate), 50mm thick precast RCC (1:2:4) cover slab (re-inforced with 8mm dia TMT bar @ 15 cm C/C bothways and suitable handle made of 10mm dia) including necessary earth work in excavation, returning filling and removal of surplus earth upto a distance not exceeding 50 m etc all as shown on electrical plate No. 3 of MES Schedule Part-I(2009) complete including testing on completion all as specified and as directed.

Supply and fixing maintenance free chemical earthing of UL Listed Copper bonded Solid Steel Rods are to be used as vertical electrode. These electrodes shall be made of high tensile low carbon steel rod, molecular bonded with 99.9% electrolytic copper with minimum bonding thickness of 254 microns - 25 mm dia copper bonded rod with minimum length of 3048 mm (10 ft as per UL) and as per IEC 62561-2. Universal clamp of required size should be made up of SS304. Polypropelene Earth pit chamber of size 300x300x190mm. Earth enhancement compund of resistivity 0.018 ohm meter - 25kg should be used made graphite and carbon should be of conductive concrete based mineral compound producing low resistance of an earth termination system. The job includes boring of 100 mm dia bore up to 3.2 mtr depth in any type of strata/ soil for placing/ lowering the pipe in pipe electrode. Material of the earthing enhancing compound shall be chemically inert to subsoil. It shall not pollute the environment. Below test report should be submitted for Earth rod should be tested CPRI tested for 87.5 kA Ipeak and 35 kA Irms for 1 sec and test reports for Marking, Dimension, Electrical resistance before and after salt mist test, tensile strength, bend test , adhesion test. The compound shall be tested and certified as per IEC 62561-7 and also fulfill Toxicity Characteristic Leaching Procedure (TCLP) requirements complete all as specified and as directed. Make: CAPE or equivalent Note : (a) The job includes excavation of pit in any type of hard dense soil/ disinterigated rocky strata (b) The job also include M & L for in PCC(1:2:4) type B1 around the FRP cover for support and foundation and colouring the PCC work with desired colour.

Material & labour for Advance encapsulated compound based Chemical earthing CPRI tesed maintenance free , pipein -pipe technology upgraded (Zinc & Alloy coated). , Zinc & Alloy coated (80 -100) microns with pure zinc (99.9%) & Alloy coating (200-250) microns. Earthing system conforming IS 3034. The outer and inner pipe should be 76.2 mm and 41.9 mm dia respectively of 3 mtrs long zinc coated with additional special alloy coating 300mm on top side for additional protection of the terminal . The annular space between the pipes to be filled up with Compact fill (CF) (Crystalline Conductive) mixture which should be machine pressed in the pipes not disintegrate or collapse when outer pipe corrodes . The inner pipe should be extended with terminals for connectivity.The job includes boring of 300 mm dia bore up to 4.0 mtr depth in any type of strata/ soil for placing/ lowering the pipe in pipe electrode , filling of pure conductolite back filling compound (BFC Conductolite ) having excellent moisture retaining capacity in 300 mm bore all around the electrode min 4 bags of 25 KG per pit per unit.The earth pit should be provided with a FRP earth pit cover for protection and safe guard of terminals. The material of earth electrode should have good electrical conductivity & anti corrosion property in wide range of soil conditions. The job also include M & L for in PCC(1:3:6) type C-1 around the FRP cover for support and foundation and colouring the PCC work with desired colour.complete all as specified and directed.

Material & labour for Advance encapsulated compound based Chemical earthing CPRI tesed maintenance free , pipein -pipe technology upgraded (Zinc & Alloy coated). , Zinc & Alloy coated (80 -100) microns with pure zinc (99.9%) & Alloy coating (200-250) microns. Earthing system conforming IS 3034. The outer and inner pipe should be 76.2 mm and 41.9 mm dia respectively of 3 mtrs long zinc coated with additional special alloy coating 300mm on top side for additional protection of the terminal . The annular space between the pipes to be filled up with Compact fill (CF) (Crystalline Conductive) mixture which should be machine pressed in the pipes not disintegrate or collapse when outer pipe corrodes . The inner pipe should be extended with terminals for connectivity.The job includes excavation of pit in any type of hard dense soil/ disinterigated rocky strata of size 1000 mm x 1000 mm x 3050 mm depth and taking out all excavated soil, lowering and placing copper electrode in centre of pit , filling of pure conductolite back filling compound (BFC Conductolite ) having excellent moisture retaining capacity in 300 mm bore all around the electrode min 4 bags of 25 KG per pit per unit.The earth pit should be provided with a FRP earth pit cover for protection and safe guard of terminals. The material of earth electrode should have good electrical conductivity & anti corrosion property in wide range of soil conditions. The job also include M & L for in PCC(1:3:6) type C-1 around the FRP cover for support and foundation and colouring the PCC work with desired colour.complete all as specified and directed.

Taking out old GI/aluminium/copper earth strip or relaying/ refixing the same existing strip with fastners of any size and type in any height and any location as directed by Engineer In charge.

Supply and fixing copper strip of size 20 x 3 mm as earth continuity conductor or main earthing lead fixed on "V" type porcelain insulator, 4 BM, heavy duty ( ceramic bus bar support insulator off white colour of suitable for mounting strip of 20 mm wide x 3 min thick) saddle to wall, buried in ground or drawn in conduit/pipe or fixed to poles or any other indicated situation for loop earthing etc. as required 20 x 3 mm copper strip brazing to each joints and connected with by providing brass nut bolts and washer all as specified and directed by Engr in Charge. Note : Insulators to be provided on every 50 cm. (Minimum 2 x insulators to be provided in every 1 x metre of strip)

Supply and fixing aluminium strip of size 25 x 3 mm as earth continuity conductor or main earthing lead fixed on "V" type porcelain insulators, 4 BM, heavy duty ( ceramic bus bar support insulator off white colour of suitable size for mounting strip of 20 mm wide x 3 min thick)) saddle to wall, buried in ground or drawn in conduit/pipe or fixed to poles or any other indicated situation for loop earthing etc. as required and connected with by providing brass nut bolts and washer all as specified and directed by Engr in Charge. Note : Insulators to be provided on every 50 cm. (Minimum 2 x insulators to be provided in every 1 x metre of strip)

Supply and fixing copper strip of size 32 x 6 mm as earth continuity conductor or main earthing lead fixed on "V" type porcelain insulator 10 BM heavy duty ( ceramic bus bar support insulator off white colour of min size of 36 mm width x 60 mm length with 36 mm width bus bar mounting base) saddle to wall, buried in ground or drawn in conduit/pipe or fixed to poles or any other indicated situation for loop earthing etc. as required 20 x 3 mm copper strip brazing to each joints and connected with by providing brass nut bolts and washer all as specified and directed by Engr in Charge.Note : Insulators to be provided on every 50 cm. (Minimum 2 x insulators to be provided in every 1 x metre of strip)