PROVISION OF RMU RING MAIN UNIT WITH ONE INCOMING AND THREE OUTGOING NEAR SMC AT AFS BAMRAULI

Amount

"Supply, installation, testing & commissioning of 11 KV of rating 630 Amps RMU unit outdoor type (IP-54) protection duly painted (Paint shade in painted Alu Zn/RAL 7032 on sheet steel for door and covers) ,SF-6 gas insulated RMU (Ring main unit) four way comprising of three numbers SF6 insulated load break switch as outgoing and one number Vacuum Circuit Breaker as incoming inside SF6 gas filled stainless steel (nonferrous and nonmagnetic grade) tank having minimum thickness 2.5 mm +/- 0.5 mm having IP-67 degree of protection with painting as per manufacturer specification & leak rate of SF-6 gas less than 0.1% , gas refillable at site. RMU should be provided with Copper Bus bar, one number fault passage indicator with each incoming and outgoing, mechanism for interlocking arrangements for powered relay complete with all accessories as under. (a) RMU type installation Outdoor Extensible type, arc proof as per IEC: 62271-200 for design, Manufacturing and testing. The RMU must have the following features/specifications :- (i) Rated Voltage upto -12 KV. (ii) Rated power frequency withstand voltage -28KV. (iii) Rated lightning impulse withstand voltage -should be minimum 125 KVP. (iv) Rated current for ring main feeder -630A. (v) Rated current for VCB feeder- 630A. (vi) Rated short-time current-21 KA/3 Sec. (vii) Rated short making current -50 KA. (viii) Ambient temperature- (-1 degree Celsius to +45 degree Celsius), (ix) Degree of protection against accidental contact and ingress of foreign objects must be assured as under :- (aa) Main electric circuits : IP-67, (ab) Fuse compartment IP3X, (ac) Operating mechanism -IPXC, (ad) Cable connection compartment -IP2XC with site replace able cable busing. (x) Each load break Switches includes:-

Supply and laying of cable , Cross linked polyethylene insulated (XLPE) armoured cable with aluminum conductor 11KV 'E' 3 core confirming to IS-7098 of cross sectional area 185 Sqmm, 3 core in trenches/through pipes/duts or on poles at crossing of over head lines of MES and road crossing complete all as specified and as directed.

Supply and fixing heat shrinkable joint box for XLPE HT 11 KV grade U/G cable suitable for cross setional area 120-185 Sqmm 3 core indoor type complete all as specified and as directed.

Earthing complete with galvanised mild steel earth electrode plate 600 X 600 X 6 mm thick buried directly and vertically in ground to a depth not less than 2.25 metres below ground level with top edge of plate not less than 1.5 metres below normal grond level and connected to galvanised iron earth strip 32x6mm size by means of bolts, nuts, check nuts and washers of galvanised iron or steel all as shown in electrical Plate No 3 of MES SSR Part-I connected to main switch board or main control board all as specified and testing on completion including provision of earth strip protected by galvanised iron 40 mm bore medium grade pipe with all fittings from the earth electrode fixed along pole with and including 25 x 6mm flat iron clamp, bolts, nuts and washers and watering pipe shall be 20 mm bore GI medium grade from top of the earth electrode to bottom of the earth pit including all excavation and earth work in any type of soil and removal of soil upto 50 metre, PCC pit with pre-cast RCC cover with handle, charcoal/salt, funnel , CI frame etc complete all as directed. Notes :-(i) The concrete pit shall be made in PCC 1:3:6 type C-1, 40mm thick precast cover slab of RCC (1:2:4) type B-1 using 20mm graded stone aggregate with suitable MS handle in lieu of cast iron cover shown in electrical plate No 3 of MES SSR Part-I. Reinforcement in RCC cover shall be of 8mm dia TMT bars laid @150mm c/c both ways. (ii) Item includes the cost of 7.5 metre GI pipe for protection of earth strip. Any variation in length shall be adjusted through deviation order. (iii) Item includes cost of 7.5 metre earth strips. Any variation in length shall be adjusted through deviation order. (iv) Plate electrode shall be surrounded by adequate quantity of charcoal dust & salt to a packed thickness of 15 cm on all sides.

Amit Engineering