SPECIAL REPAIR TO EARTHING PITS AND ALLIED WORKS AT AF STN DEVLALI

M&L for Maintenance free chemical earthing system complete electrode earthing maintenance free earthing based on 6 mtr long Pure Copper solid rod electrode of dia 17.2 mm and filled with high purity electrically conductive granular material having ultralow resistive value of 0.01 Ohm-m. Earthing Electrode shall be made by embedding pure copper electrode in 100mm dia Macronite conductive concrete made by mixing high purity conductive granular mixed with cement in the ratio 2:1 (2 part of high purity electriclly conductive granular and 1 part cement and one litre of water per kg of mix ). The earthing electrode shall be augured in bore hole of dia not less than 150mm and 6 Mtr depth. The conductive material shall confirm to BIS: 3043-2018. The rod shall be embedded in conductive concrete at factory with concrete having resistivity 0.040 Ohm-m. The top edge of the electrode shall comprise of plate provided with 04 holes for connections of the earthing strip,including brass nut bolts for connections of the strip the copper strip shall be duly brazed/welded with connection terminal of earthing rod, including PCC chamber in PCC (1:3:6) typeC-1 (using 20mm graded stone aggregate) with Pit cover of 300mmX300mm made of Cast Iron cover with liftting arrengement complete all as specified and as directed by Engr-in-Charge.. All the material such as copper rod and concrete mix shall be Ph nutral, chemicaly inert and non corrosive. i) The contractor shall submit type test report issued by the CPRI for high purity, electrically conductive earthing, confirms to rated short time withstand current 20 KA per sec. ii) The factory made electrode shall be tested at factory and test report shall be submitted. iii) Factory testing of individual earthing shall be carried out in presence of rep of accepting officer and report shall be submitted. iv) The contractor shall obtain make approval for high purity electrically conductive granular duly by submitting certificates conforming to resistivity is 0.01 ohms by granular manufacturer. v) On installation of earthings at site, For achieve less then 1 ohm resistance if required grid then it's under contractor scope, If desired resistance is not achived the contractor shall redo the same without any extra cost. vi) The contractor shall submit certificate issued by OEM of earthing electrode starting that " The desired maintenance free earthing resistance less than 1 ohm." Note : (i) Excavation work should be done by mechincally or manpower only. (ii) Earth test should be done by contractor at his own cost and submit result sheet every month up to wrranty period after the compleation of work with user satisfaction and signature, if required result is not found at site, entire earthing should by contractor again without accruing any extra cost to the department. No claim whatsover on redoing the earthing shall be admissible by the department to the contractor.

All aspe Item No 1 but earth resistance below 2 Ohms including excavation and earth work and earth neutral voltage less than 03 Volts of PCC chamber in PCC (1:3:6) typeC-1 (using 20mm graded stone aggregate) with Pit cover of 300mmX300mm made of Cast Iron cover with liftting arrengement, expect condition No (v) item no 1 above complete all as specified and as directed by Engr-in-Charge. Note : (i) Excavation work should be done by mechincally or manpower only. (ii) Earth test should be done by contractor at his own cost and submit result sheet every month up to wrranty period after the compleation of work with user satisfaction and signature, if required result is not found at site, entire earthing should by contractor again without accruing any extra cost to the department. No claim whatsover on redoing the earthing shall be admissible by the department to the contractor.

All aspe Item No 1 but GI pipe 75 mm dia(ID) medium grade earthing with 75 resistance below 3 Ohms including excavation and earth work and earth neutral voltage less than 03 Volts of PCC chamber in PCC (1:3:6) typeC-1 (using 20mm graded stone aggregate) with Pit cover of 300mmX300mm made of Cast Iron cover including liftting arrengement complete all as specified and as directed by Engr-in-Charge. Note : (i) Excavation work should be done by mechincally or manpower only. (ii) Earth test should be done by contractor at his own cost and submit result sheet every month up to wrranty period after the compleation of work with user satisfaction and signature, if required result is not found at site, entire earthing should by contractor again without accruing any extra cost to the department. No claim whatsover on redoing the earthing shall be admissible by the department to the contractor

Material and labour for earthing complete with earth resistance below 6 Ohms galvanized steel earth plate electrode of size 60cm x 60 cm x 6 mm thick buried directly in ground ( earth pit not less than 2.25 mtr deep below ground level) with top edge of earth plate not less than 1.5 mtr below ground level connected to galvanized iron strip 32 x 6 mm by means of of galvanized iron nuts & bolts or as directed at site by Engineer -in-Charge protected by GI Pipe 40 mm dia light grade and connected to test point and further connected to equipment, mcachinery, electrical panel or any other as directed by Engineer-in-Charge, which to be earthed, all as shown in electrical plate No 3 of SSR Part I including providion of concrete earth pit constructed in PCC 1:3:6 type C-1 as earth pit and PCC 1:2:4 type B-1 for cover slab with necessary reinforcement with handle for lifting also including provision of funnel with wiremesh with 20 mm GI pipe medium grade for watering, charcoal and salt in alternative layers of 15 cm thick all around the electrode , including necessary excavation and earth work , testing and commissioning complete all as directed at site.

S&F green colour PVC Covered High Conductivity copper Tapes/Strip of size 25x3 mm or ( as per exisitin) Complete all as specified and directed. Note :- Joint of Strip will be done by Exothermic Welding/brazing or as per direction by Engr-in-Charge.

S&F green colour PVC Covered High Conductivity Galvanized Earth strip Tapes/Strip of size 25x4 mm or ( as per exisitin) Complete all as specified and directed. Note :- Joint of Strip will be done by Exothermic Welding/brazing or as per direction by Engr-in-Charge.

S&F Earth Pit marker made of metal sheet of size 200 mm x 150 mm x 3 mm with 1.2 mtr long iron rounded road with syentetic enamal paint over coat of read oxide primer shade of colour and writing detail complete all as directed by Engr-in-Charge.

M&L insulator porcelain/polycarbonate/wooden block with suitable fixing arrangements for roof and down conductor duly insulated from wall surface/roof of the building all as directed. of size 25x3 and 32 x 6 mm as per site requirement complete all as specified and directed

M&L for Exothermic Welding/brazing of existing copper earthing including all brazing materials as required at site complete all as specified and as directed.( Note :- The rate of T&P , Gas cylinder , weilding machine etc are included in the quoted rates quoted by the contractor

M&L for Exothermic Welding/brazing of existing galvanised earthing with GI/steel welding rod including all brazing materials as required at site complete all as specified and as directed.( Note :- The rate of T&P , Gas cylinder , welding machine etc are included in the quoted rates quoted by the contractor

M & L for making earth testing point with copper strip of size 25 x 3 mm ( 20 cm length) with support of insulator porcelain/polycarbonate with suitable fixing arrangements for down conductor duly insulated from wall surface of the building complete all as specified and directed by Engr –in-charge

M & L for making earth testing point with GI strip of size 36 x 6 mm ( 20 cm length) with support of insulator porcelain/polycarbonate with suitable fixing arrangements for down conductor duly insulated from wall surface of the building complete all as specified and directed by Engr –in-charge

M&L in repairs to earthing pit chamber including replacement of PCC chamber, cement concret pit with cast iron miled steel frame embedded in the massonery enclouser finished flushed & PCC cover 10 mm thick (300mmx300mm having locking arrengment hinged to PCC frame all as shown under electrical plate of SSR Pt - I 2009 and as directed including painting the external surface of chamber & cover with enamel paint in diffrent colour as directed and writing earth results & date of test carried out with white paint on black painted background, complete all as directed.

Tking down hanging exisiting earthing strip any size and refixing with new insulator at its original position complete as per direction Engr-in-Charge

Excavation in trenches, n.exc 1.5 m wide and n.exc 1.5m in depth in hard dense soil for laying of GI tubing and getting out the soil

Returning filling in, including spreading,levelling, watering and well ramming in layers n.exc 25cm of hard/dense soil

Removing excavated soil n.exc 50m and depositig where directed at a level . n,exc1.5m above starting point.

Supply and lay Pipes galvanized medium class laid in trenches , roof, fitted on wall plinth complete with saddle coupling complete including elob.Tee GI fittings 25 mm bore complete all as specified and directed by Engr -in-Charge

All as per item No 4 above but of size 15 mm bore

Supply and fix in repairs Gun metal globe or gate valve 25 mm dia with brass gate with iron wheel head, screwed both ends, for iron pipe

Cutting of exisiting DI /GI pipe line 20 to 25 dia for certaining/Tapping as directed GI pipe with thread, union Tee elbow complete Lick proof all as specified diretced by Engr-in-Charge.

S&F Self closing taps of cast iron or malleable cast iron, galvanised, screwed for iron pipe of size 15 mm bore and fixed complete all as specified and directed by Engr -in Charge

Boring of holes under road, pavement, hard standing by trenchless technology using ultra sounding technique and necessary machine including HDPE pipe of 100 mm dia suitable for 0.4 mpa working pressure.