REPAIR/REPLACEMENT AND IMPROVEMENT OF EARTHING AND CONNECTED WORKS AT AF STN ADAMPUR

Amount

Earthing with and including GI medium grade 40mm bore and 2.5m long pipe electrode with 4 Sq. mm GI wire earthing lead complete all as shown in electrical plate No. 2 and as specified in Particular Specifications clause 19.1.1 of contract, IN REPAIR.

Earthing with and including GI earth plate electrode 6 mm thick of size 600 mm x 600 mm with 25 mm x 4 mm GI strip earthing lead complete all as shown in electrical plate No. 3 and as specified in Particular Specifications clause 19.1.1 of contract, IN REPAIR.

Earthing with and including GI earth plate electrode 6 mm thick of size 600 mm x 600 mm with 32 mm x 6 mm GI strip earthing lead complete all as shown in electrical plate No. 3 and as specified in Particular Specifications clause 19.1.1 of contract, IN REPAIR.

NOTES APPLICABLE TO SERIAL ITEM 1 to 3: Earth resstance shall be less than 3 ohm. In case the test results are not found less than 3 ohm, complete earthing shall be redone by the contractor without any extra cost to Govt.

Earthing with and including copper earth plate electrode 3.15 mm thick of size 600 mm x 600 mm with 20 mm x 3 mm copper earthing strip complete all as shown in electrical plate No. 3 and as specified in Particular Specifications clause 19.1.1 of contract, IN REPAIR.

NOTES APPLICABLE TO SERIAL ITEM 4: Earth resstance shall be less than 2 ohm. In case the test results are not found less than 2 ohm, complete earthing shall be redone by the contractor without any extra cost to Govt.

Chemical earthing with and including copper earth plate electrode 5 mm thick of size 900 mm x 600 mm with 32 mm x 6mm copper strip earthing lead, complete all as shown in electrical plate No. 3 and as specified in Particular Specifications clause 19.1.2 of contract, IN REPAIR.

NOTES APPLICABLE TO SERIAL ITEM 5: Earth resstance shall be less than 1 ohm. In case the test results are not found less than 1 ohm, complete earthing shall be redone by the contractor without any extra cost to Govt.

Maintenance free earthing with 02 Nos. copper earth plate electrode 3.15 mm thick of size 600mm x 600mm, burried directly in ground vertically wih top edge of earth plate (s) not less than 2.80 m below normal ground level, placed apart in separate pits & inter-connected with two run of 25 x 3 mm copper strip 1.5 m long (Depth of earth pit not less than 3.70 m below normal ground level ) & 16 mm dia solid copper rod 3.00 m long with 250 micron copper coating, placed in centre vertically with top edge not less than 2.80 m below normal ground level (Copper rod surrounded with highty conductive and non-corrosive approved material) by boring a 6.10 mm hole with drill machine/auger of suitable bore, earth plate surrounded from all sides by 15cm thick packed alternate layers of approved agricultural/cotton soil mixed with earth/ground resistance chemical compound/ material of approved by GE, 25 x 6 mm thick copper strip by means of oxycetelance copper bazing as directed, connecter exposing 6" above ground level as for length resistance, earth lead protected with light gade GI 40 mm bore tube (except exposing portion) & megger testing of the installation for desired result of resistance IN REPAIR, complete all as specified.

NOTES APPLICABLE TO SERIAL ITEM 6: (a) Earth resistance should be less than one Ohm. In case the test results are not found below one Ohm , complete earthing will be redone without any extra cost of Govt . (b) Poly plastic cover shall be provided over earth pit and quoted rate shall deemed to include the cost. (c) The fresh soil to be filled upto cover the top portion of electrode except of strip protruding 6" above ground, ouring water and allow the soil to consolidate. (d) The electrode not to be disturbed/shaked/rotated for about 2-3 days to enable it set firmly. (e) 10 years "Performance Guarantee" as mentioned in PS clause 3.3.3

Earth continuity conductor or main earthing lead fixed to wall on batten or recess or chases or buried in ground or drawn in conduit/pipe or fixed to poles or any other indicated situation for loop earthing etc. as required complete all as specified, IN REPLACEMENT, with & including the following: -

Copper strip of size 20mm x3.15mm.

GI strip of size 32mm x6mm.

Aluminium strip of size 25mm x3.15mm.

NOTES APPLICABLE TO SERIAL ITEM 7: (a) Strips to be fixed with porcelain/polymer insulators at the intervals of 0.6 metre so as not to be in electrical contact with building structure. (b) Brazing shall be done on both sides (overlapping) at all joints except test point.

Earth continuty conductor galvansed iron or seel wire main earth lead fixed to wall on batten or recess or chases or buried in ground or drawn in conduit/pipe or fixed to poles, IN REPLACEMENT, complete all as specified, of sze: -

4 sq. mm dia.

6 sq. mm dia.

Air termination, single pointed aluminium rod 12 mm dia 300 mm long IN REPLACEMENT, complete all as specified.

Air termination, single pointed copper rod 12 mm dia 300 mm long IN REPLACEMENT, complete all as specified.

Test point terminal block made of gun metal or phosphorus bronze size 75 x 75x 25 mm drilled and screwed including 3 Nos. 8 mm dia 25 mm long hex head screw IN REPLACEMENT, complete all as specified.

Salt (quantity recommended by Engineer-in-Charge) pouring into earth pit thrugh watering pipe by mixing the same with water to maintain earth resistance value of earthing within permissible limit complete.

Charcoal/coke powder (quantity recommended by Engineer-in-Charge) pouring into earth pit thrugh watering pipe by mixing the same with water to maintain earth resistance value of earthing within permissible limit complete.

Magnesium sulphate chemical (quantity recommended by Engineer-in-Charge) pouring into earth pit thrugh watering pipe by mixing the same with water to maintain earth resistance value of earthing within permissible limit complete.

Reinforced cement concrete, type A-1 (1:1½:3), using 20 mm graded stone aggregates as in precast earth pit cover 40 mm thick of size 550-600 mm x 550-600 mm reinforced with XPM weighing not less than 4 kg/Sq.m and fixed on directed location IN REPLACEMENT of existing broken cover complete all as specified.

Light grade GI tube, cut to pieces1.5 metre length & fixed vertically on directed location in and including 200 mm x 200 mm x 150 mm size PCC (1:2:4) type B-1 block including necessary form work with fair fiished surface and connectining other (top) end to air termination rod with necessary bolts, washer and nuts etc IN REPLACEMENT, complete, size of tube as under: -

25 mm bore

40 mm bore

50 mm bore

Brazing/soldering on both sides (overlapping) to the metal strip of any size provided as earth earthing lead including dismanting the old from the existing position/ equipment without disturbing the functional requirement and reconnecting complete.

N S ENGINEERS

AAR KAY BEE ENTERPRISES

ACR ENTERPRISES