SPECIAL REPAIRS TO EARTHING PITS AT AF STATION OJHAR

Amount

Soil resistivity all as per standard Engr practice and as directed

Material & labour for earthing complete supply, install , testing and commissioning maintence free comprising of high tensile low carbon steel rod of 3 mtrs length & 17.2mm dia with 250 micron (average) molecularly bonded copper on the outer surface to confirm with the requirement of UL 467 placed in bore min 150mm dia upto 3 mtr deep with and including necessaary excavation by any means in any type of soil/strata like soil, rock or any other black soil, rock or any other along with back-fill compound strictly be a carbon based conductive concreate type which was resistively of less than 0.12 ohm mtr as per clause 14.5 D of IEEE:80Standard back-fill compound should be electronically conductive (like in metals) and should not depend on moisture for condition. Compound shall be suplied in sealed bags. The earth electrode should finally be housed in heavy duty concreate/PVC chamber with cover of size 300x300x300mm for future access. Back-fill compound should be enviroment freindly, should solodoty when mixed with water and should not leach/diffuse into ground.

Material & labour for earthing complete supply, install , testing and commissioning maintenance free Tripod earthings comprising of high tensile low carbon steel rod of 3 mtrs length & 17.2mm dia with 250 micron (average) molecularly bonded copper on the outer surface to confirm with the requirement of UL 467 placed in bore min 150mm dia upto 3 mtr deep with and including necessaary excavation by any means for tripod earthing in any type of soil/ strata like soil, rock or any other encluding back-fill compound strictly be a carbon based conductive type which has resistively of less than 0.12 ohm mtr as per clause 14.5 D of IEEE:80 Standard, 03 Nos earth electrode to be fixed at a distance of 3 Mtr to each other (in Triangle) and inter connected with and including copper strip of size 25x3mm and back-fill compound should be electronically conductive (like in metals) and should not depend on moisture for condition. Compound shall be suplied in sealed bags. The earth electrode should finally be housed in heavy duty concreate/PVC chamber with cover of size 300x300x300mm for future access. Back-fill compound should be enviroment freindly, should solodoty when mixed with water and should not leach/diffuse into ground.

Taking out complete earthing from ground in any type of strata and making the disturbed surfaces all as directed by Engr-in- Charge.

M&L for earthing in repair including taking out GI plate with pipe and complete with galvanised steel earth plate electrode 600x600x6mm thick,burried directly in ground (earth pit not less than 2.25 Mtr deep below ground level ) with top edge of the pl;ate not less than 1.5 Mtr below normal ground level,connected to galvanised iron strip 32x6 mm as earth lead by means of bolts,nuts ,washer and check nut of galvanized steel, protected by and including GI pipe 50 mm bore (light grade) and connected to main switch / MCB DBs box point / LP test point as directed and including cement concret pit in 1:2:4 type B1 using 12.5mm graded aggregate, with cast iron miled steel frame embedded in the concrete enclouser fineshed flushed & CI cover 10 mm thick of size (300mmx300mm CI) having locking arrengment hinged to CI 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, wiremesh funnel 20 mm bore GI pipe medium grade for watering adequate quantity of charcol and common salt in alternate layer of 15cm 3ft x 3ft thick all around the electrode including necessery excavation & earth work in any type of soil , rock /strata/ other if any, complete testing on completion all as directed. Note:- i) Filling the pit with black cotton soil brought at site.from out of defence land. ii) The excavated soil will be removed iii) Earth resistance should be less than 4 ohm. iv)GI strip up to 7.5 RM with GI pipe 40mm dia is included in the quoted rate.(v) If resistance value is found more than 04 ohm, any time after execution upto end of defect liability period contractor has to do needful action within 07 days without any extra cost to bring the value less than 04 Ohm, failing which the cost of the earthing (as quoted by the contractor or prevaling in the market whichever is high) will be recovered from the contractor.

Supply & fix earth continuty conductor or main earthing 32X6 mm dia galvanised iron strip. (roof conductor or down conductor ) above ground level fixed to wall/ roof duly insulated on batten or fixed on new porcelain insulators with clamping device or recessed or chases or burried in groung/ floor or drawn in conduit/ pipe or fixed to poles or any other indicated situation for loop earthing etc as required all as directed by Engg. in charge. Note :- i) the distance between porcelain insulator will be included with cost of T & P and labour required to work on roof top at lateral faces of existing hangers upto height of 25 mtrs.

Ditto but 25 x 3 mm copper strip.

Taking down existing Copper strip/GI strip any size with its accessories and refixing the same complete all as directed.

Supply & Fix 25 x 3 mm aluminium strip ( Roof conductor or down conductor) above ground level fixed to wall/ roof duly insulated fixed on and including new porcelain insulators with clamping device or recessed or chases or burried in ground/ floor or drawn in conduit / pipe or fixed to poles or any other indicated situation or for loop earthing etc. Note :- i) The consecutive distance between porcelain insulator will not be more than 40 cm. ii) The quoted rates shall be deemed to be included with cost of T&P and labour required to work on roof top and at lateral faces of existing hangers upto height of 25 Mtrs.

M&L for GI tubing medium grade with all fitting laid in trenches or fixed to wall or ceiling with clamps or fixed to floor complete all as specied and directed of size 15 mm bore.Make : Swastik/Prakash Surya/Apollo.

M&L for GI tubing light grade with all fitting laid in trenches or fixed to wall or ceiling with clamps or fixed to floor complete all as specied and directed of size 50 mm bore.Make : Tata/Jindal/Prakash Surya/Apollo.

Drilling and tapping cast iron water mains ( in position ) for branch connections of internal dia of 15mm all as directed.

Cutting existing steel tubing for alteration or additions and screwing existing steel tubing for and including insertion of tee 15mmx15mmx15mm alterations or addition

S&F stop valve, cast copper alloy, screwed down, high pressure, with crutch or butterfly handle, screwed both ends for fixing with 15 mm iron pipe or for union complete all as specified and directed.

Excavation in trenches not exceeding 1.50 mtr wide and not exceeding 1.50 meter in depth and getting out in soft/loose soil all as directed.

Returning filling in trenches including spreading leveling watering and well ramming in layers not exceeding 25 cm all as directed.

Removing of surplus soil not exceeding 50 meter and depositing where directed at a level not exc 1.50 mtr above the starting point all as directed.

Note:- The amount of schedule of credit on page No. 25 shall be deducted from the amount quoted against sch 'A' while deriving at the contract sum for accptance.

LAL AND SONS