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| 1 | M&L for study of earth/soil resistivity (tomographic survey of soil) by Conducting earth resistivity test using earth tester to find out the resistivity of the plot and to obtain polar resistivity curve and average resistivityin eight direction at AF Stn Mohanbari and submitting the report with recommendation and complete detailed specification of earthing to be considered for obtaining earth resistance value less than 1 ohm complete all as specified and directed. Note :-(i) The unit rate also include for necessary excavation in any type of soil(ii) Report shall be submitted in duplicate set. (iii) Study at one location shall be measured and paid at one job.(iv)Contactor shall submit guarantee @ 10% of quoted rate against this item to ensure earthing results as per design. The same shall be released after successfully completion of Phase-II.) |
| 2 | M&L for earthingwith copper earth plate electrode 600 mm x 600 mm x 3.15 mm thick, burried directly in ground vertically to a depth of not less than 2.25 mtr below ground level connected to copper strip of size 20 x 3 mm as earthing leadmeans of nut, bolts and washers made out of Brass and 40 mm dia GI pipe \"light grade\" for protection of earth lead and connected to contoll board or main switch or as directed by Engr -in-Charge including earthing pit in PCC (1:3:6) type C-1, pre-cast reinforced cover with MS XPM Jalli, RCC 1:1.5:3 cover slab of size 300 x 300 x 100 mm with one handle made out of 8 mm dia round bar 20 mm dia GI pipe light grade for watering funnels, wire mesh and provided charcoal or coke of alternative layers of 15 cm including necessary earth work complete shown in electrical plated No 3 and tesing complete all as specified and directed. NOTE : (i) The earthing pit should be provided with proper earth pit and pit cover. Pit cover should be painted with synthetic enamel paint of approved colour and pit number to be marked on a GI plate above 45 cm from GL as per colour code followed in AF Station.(ii) If the desired earth registance is not achive during testing as per IS the complete earthing shall be carried out by the contractor at his own cost and no extra claim shall be admissable. |
| 3 | S&F for aluminium strip of size 25x3.15 mm for earth continuity conductor fixed on PCC block complete all as specified as directed complete all as specified and directed. |
| 4 | S&F for Air termination, single pointed, copper rod 12 mm dia and 300mm long fixed on copper strip for earth conductivity to ground complete all as specified and directed. |
| 5 | S&F for test point terminal block made of gun metal or phosphorous bronze, size 75mm x 75mm x 25 mm thick, drilled and screwed including 3 Nos. 8 mm dia. 25 mm long hexagonal head screws, includingMS box 2 mm thick of suitable size for protection of test point terminal, including dismantling of old unserviceable test pointcomplete all as specified and directed. |
| 6 | S&F for porcelain insulator of size 65x31 mm and height 30mm with three nos hole including GI bolts and nuts of required size and two nos washer on PCC, fixing strip complete all as specified and directed. |
| 7 | S&F for GI pipe of 80 mm dia medium grade incl making of cap at top of pipe with the help of GI sheet. GI Pipe are used to fixing of lightning protection system including necessary arrangement for fixing of porcelain insulator for laying of strip complete all as specified and directed. |
| 8 | M&L for PCC work providing PCC type B2 (1 : 2 : 4) with 20 mm graded stone aggregate in foundation for porcelain insulator/ Pole and finishing the surface even and smooth without using extra cement including complete all as specified and directed. |
| 9 | M&L for 20X3 mm copper strip for earthing connection to building complete all as specified and directed. |
| 10 | S&F for GI protection pipe of 40 mm dia light grade for LA / strip protection including all fittings laid in trenches or fixed on pole/ walls/ laid in floor with mild steel clamps, bolts, nuts and washers complete all as specified and directed. |
| 11 | M&L for installation and testing of maintenance free earthing complete with earth electrode as per IS 3043 or latest tested for 254 micron copper bonded low carbon steel pipe of 3 meter long, minimum 6 Nos of electrode and maximum as designed and approved under Phase-I), 50 mm outer dia of electrode with 25 x 3 mm inner copper strip buried directly in ground and tapered at the bottom 175- 200 mm dia digging or auguring of earth to the required depth as approved tomographic survey report (received under Phase I above) and filled up in bottom with slurry 50 Kg per electrode plain bentonite for moisture and then with earthing chemical as per design under Phase-I as per IS/ IEC-62561-7 of Balanced Ph and less than 0.2 Ohm resistivity carbon based earth enhancing compound in slurry form and quantity as per design. An arrangement for connection of copper strip (25x3mm) to electrode connected by means of Universal Copper Ground Rod Clamp of size 135x35x3mm to the electrode, copper earth strip 25x3 mm connected by means of clamp, provision of HDPE pit cover with minimum 5 KN load capacity chamber with cover including necessary excavation in any type of soil, returning filling in, removal of surplus soil complete all as specified and directed. |
| 12 | Contd 2/....Note:-(i) Phase-I completion is mandatory prior to start of work at a particular location.(ii) Earthing system shall be designed so as to achieve test result less than 1 Ohm depending upon the soil conditions for the minimum 02 Years under warranty.(iii) Copper strip to be extended upto the equipment and power room. It should be routed on the side wall of the underground duct fixed with ceramic/ porcelain/ PVC spacers and hot sleeves.(iv) Readymade HDPE pit chamber with cover having minimum load capacity 5 KN with connected items.(v) Copper strip should be 25x3 mm and length upto 7.5 Mtr is deemed to be included in the item qouted rate.(vi) The number of earthing electrode in each earthing pit shall be as per design carried out in Phase-I. Any extra cost for universal number of pits as per design shall be deemed to be included in item quoted rate.(vii) The Phase-II work shall be commenced after completion of Phase-I work. Make: As approved by GE on the basis of report received under Phase-I. |
| 13 | Material and labour laying well burnt old sizebricks, straight or curved on plan , laid flat with width equal to length of brick , laid dry over electric cable for protection all as specified. |
