PROVN AND UPGRADATION OF EARTHING PITS AND LIGHTNING ARRESTERS AT VARIOUS LOCATIONS (PH-I) AT AF STN TEZPUR UNDER GE (AF) TEZPUR

Amount

Excavation in trenches in any type of soil not exceeding 1.5 mtr wide and n.exe 1.5 mtr depth including getting out all as specified and directed. Note : Manual excavation to be done. During excavation if any damage occured to existing cable any type/ water pipe line, it will be contractor responsibilty to get it repair and make functional by providing new jointing kit etc without any extra cost. Contractor has to repair it within 24 hrs so that essential service can not be effected due to such damage.If contractor fails to repair it within 24 hrs penalty @ Rs 500/ per day will be imposed to contractor till rectification of defects. In this aspect GE decision will be final , conclusive and binding.

Returning filling in any type of soil , including, spreading levelling watering and well ramming in layers not exc. 25 cm complete all as specified and directed.

Removing surplus excavated material from site not exceeding 50 mtrs from starting point and depositing where directed at level not exceeding 1.5 mtr above the starting point all as specified and directed.

Supply and Laying galvanized steel tubing,40 mm bore, light grade, in trenches or fixed to poles/Walls etc, for cable protection, with and including all connected fittings complete all as specified and directed.

Cutting chase for pass through cable protection pipe ,etc.in existing plain cement concrete pavement/ hardstanding/aprons etc. and making good, cutting in plain cement concrete (1:3:6) Type C1(using 20 mm graded aggregate),exceeding 20 cm but not exc 50 cm girth, complete all as specified and directed.

M&L Test point terminal block made of gun metal or phosphorus bronze size 75 x 75 x 25 mm drilled and screwed incl 3 Nos 8mm dia 25mm long hexagonal head screws for fixing strips to test point including necessary fixing arrangement to fix test point terminal block in junction box complete all as specified and directed.

Supply and fixing copper strip of size 20 x 3.15 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 shall be provided on every 50 cm. (Minimum 2 x insulators to be provided in every 1 x metre of strip and rate of the same deemed to included in quoated rates)

Supply and Fix , Cable Junction Box, IP66 ‘halogen free and weather proof’, size 210 mm (W) x 260 mm (H) x 117 mm (D), with knock outs for cable entry for cable size 16-35 sq mm with 03 (Three) Nos.Grommets, IP 65, cable entry M 32, of Make “Hensel”KM8350 or equivalent Model of Make ‘Sintex Industries Ltd’/'C&S Electric Ltd',fixed to wall/ pole with suitable aluminium strip clamp 25 X 3 mm, nuts, bolts and washers, including provision of 15 Amps,4 pole,open bakelite terminal block connector,complete all as specified and directed.

Supply,Design, installation, testing and commissioning for Advance encapsulated compound based Marconite compound or equivalent as per OEM recommendation CPRI tesed earthing maintenance free , with copper electrode of 80 mm dia (strip in pipe technology upgraded earthing system conforming IS 3043. The outer copper pipe shall be of 80 mm dia or manufacturer instruction and inner copper strip shall be of 25 x 3 mm respectively of 3 mtrs long with terminal size 50 x 6 mm . The annular space between the pipe and strip to be filled up with Compact fill (CF) (Crystalline Conductive) mixture. 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 and filling of back fill marconite compound having excellent moisture retaining capacity in sourrounding of electrode in 300 mm dia all around the electrode( Min 4 bags of 25 Kg each of Marconite back fill compound per pit per unit to be fill or more quantity of BFC if required to achive less than one ohms). The remaining portion of earth pit to be filled with agriculture soil / black cotton soil free from stones etc to be bring from out side defence land . 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(1:2:4) type B1 around the FRP cover for support and foundation and colouring the PCC work with desired colour.complete all as specified and directed.NOTE: 1) The quantity of BFC indicated above is generally for normal/good soils.In case the soil resistivity is high , the quantity of BFC should be increased & cost of the same is deemed to be inclusive in the quoted rates.

Continuie Note ... 2). If the desired earth resistance not obtained the earthing shall be re-done by contractor without any extra cost to Govt . 3). Removal of excavated soil and filling of agriculture soil brought from out side defence land shall be included in the overall rate quoted.Make : Copper electrode : True Power Earthing Pvt Ltd. Model No. 80/3MTPPC (3 MTR Long, 80 mm dia) Product code CE -E-003 or equivelant make. Back fill compound : Marconite : Product of Carbon International Ltd. UK. "Marconite" electrically conductive aggregate, to be used as backfill to enhance the effect of earth electrode and suitable for rock and all type of ground condition having low resistivity up to 0.001 Ohm meter, inert PH material, Corrosion free green product in bag of 25 Kg each or equivalent as per OEM recommendation) Note :- (i) Design of earth electrode should be of Strip -in-pipe technology . (ii) Contractor have to submit literature of earth electrode and get the make approved of GE before procurement. (iii) The earth electrode shall be CPRI approved. (iv) Contarctor has to fill pure back fill compound all around the earth electrode in 300 mm bore up to full depth of bore. (v) Copper strip will be laid below 20 cm from ground level and connecting the test point through plinth protection using HDPE pipe for protection, necessary cost of repair to plinth protection and brazing and welding deemed to be included in the item. (vi) Contarctor shall submit the test report of earthing after completing the work of earthing. (vii) Contractor shall remove and disposed off the soil excavated from boring and clear the site before completion of work. (viii) Contractor has to submit the test certificate of electrode and back fill compound before claiming the payment. (ix).The cost of Copper strip of size 20X3.15 mm from top of earth plate upto 7.5 meter above ground level is deemed to be included in the unit rate of above item.and copper strip beyond 7.5 RM will be measured seperately.

Supply,Design, installation, testing and commissioning of maintenance free (Four spikes) CPRI tesed chemical earthing system conforming IS 3043 using 17.2mm dia, 3000mm long (drawn vertically) high tensile low carbon steel circular rod, molecularly bonded with copper on outer surface (minimum copper bonding thickness of 250 microns) meeting the requirements of under writers laboratories (UL) 467-2007 or latest with 250mm long copper strips of size (50X3)mm, exothermally welded on top of electrode complete including The annular space between the pipe and strip to be filled up with Compact fill (CF) (Crystalline Conductive) mixture. 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 and filling of back fill marconite compound or OEM recommended having excellent moisture retaining capacity in sourrounding of electrode in 300 mm dia all around the electrode and back filling with chemical compound earth enhancing back filled compound as per IEEE 80 2000 clause 14.5b, conforming to IEC 62561-7, min quantity of compound used 80 Kg per electrode and minimum 62 Kg earth enhancing back filled compound as per IEEE 80 2000 clause 14.5b, conforming to IEC 62561-7 required for mixing with soil for pit to pit interconnection, However extra chemical is required to fill the hole around the rod, same shall be deemed to be included in the unit rate of this item) conforming to IEEE/BS standrads with agricultural soil for each pit and pit to pit interconnection, incl HDPE pit cover light weight made out of high quality polymer with lid made of HDG steel and U-clamp copper nut & bolt & gun metal body 1 No. per electrode required for joining all three electrodes complete all as specified and as directed. Note:- (i) The work of earthing shall be carried out by authorised trained rep of OEM.

(ii) The acceptable earth resistance at earth busbar/ test point shall be below 01 ohm, If the desired earth resistance not obtained, contractor has to make additional earthing with interconnection to same earthing, Cost for additional earthing and interconnection to same earthing with copper strip will be deemed to be included in quoated rates. (iii) The procedure mentioned here-in-before for one earth pit shall be repeated for other earth pits. (iv) Copper strip 20x3.15 mm required for joining these four electrodes in loop shall be deemed to inclusive in quoated rates . (v)The distance between two successive earth electrodes shall not be less than 3 metres.(vi) The rate quoted shall also be included the following elements: (a) Complete earthwork including drilling holes for electrode.(b) Earhing electrode-04 only (c) Backfilling carbon based ground enhancing compound (GEC) (d) Pit cover light weight made out of high quality polymer with lid made of HDG steel. (e) Agricultural Soil brought from out side defence land shall be included in the overall rate quoted ,required for each pit and pit to pit interconnection (f)Copper strip as earthing lead of size 50mmx3mm, (g) All labour and T&P required including testing of earth network. (h) Testing for earth resistance shall be carriedout by the contractor in presence of JE and Engr-in-charge. (J) Original purchase vouchers for copper rod and back fill compound and manufacturer test certificate of entire quantity shall be produced by the contractor before commencement on ground.(k) The Earthing and pit to pit interconnection shall be performed with Agricultural (l) Contarctor has to fill pure back fill compound all around the earth electrode in 300 mm bore up to full depth of bore. (m) Copper strip will be laid below 20 cm from ground level and connecting the test point through plinth protection using HDPE pipe for protection, necessary cost of repair to plinth protection and brazing and welding deemed to be included in the item. (vii) Contractor shall remove and disposed off the soil excavated from boring and clear the site before completion of work. (viii) Contractor has to submit the test certificate of electrode and back fill compound before claiming the payment. (ix).The cost of Copper strip of size 20X3.15 mm from top of earth plate upto 7.5 meter above ground level is deemed to be included in the unit rate of above item.and copper strip beyond 7.5 RM will be measured seperately. The quantity of BFC indicated above is generally for normal/good soils.In case the soil resistivity is high , the quantity of BFC should be increased & cost of the same is deemed to be inclusive in the quoted rates.

Singhs Construction (BID ID -3258808)

kabitaconstruction (BID ID -3259093)

SHRI D. C. BISWAS (BID ID -3260182)

M/S SHIVAYA ENGINEERING (BID ID -3260031)

M/S Kangkans (BID ID -3260104)

M/S Annu Electronics (BID ID -3260103)

KAILSON (BID ID -3259766)