MID/AN/91

Providing/Installation/Testing and Commissioning of 800-amp Vacuum Circuit Breakers for 300 KW HT motor including safety devices under following scope of work: - SCOPE OF WORK: - The work includes Design, manufacture, assembling, supply, installation, testing and commissioning of outgoing VCB- 02 Nos, HT panel 6.60 KV±10% of normal current carrying capacity 800 Amp. with short circuit breaking current of 26 KA in 3 seconds for operation of three phase, slip ring type, low speed, 300KW HT induction motor; complete dismantling of old /damaged installed HT panels and stacking them at suitable place in the store premises & job also includes other related works required for successful installation, testing and commissioning of new VCB panels. Panels consisting of outgoing VCB-2 Nos with inter changeable trolly and also connected accessories i.e. electrical measuring instruments, C. Ts, P. Ts, Digital/Numerical type motor Protection relays, indicators, Bus Bars, insulators etc.(complete). The HT Panel shall be integrated cubical type metal clad, floor mounted, free standing for indoor installation with fully draw-out type breaker carriage and shall comprise of standard pre-fabricated CRCA sheet units assembled (bolted) with integrated base frame at bottom to form a rigid, freestanding structure Sheet thickness of various parts 2 mm for front door, Metering chamber & front door VCB chamber, bottom gland plate & base plate -2.5mm. All load bearing sheet thickness should be min. 2.5mm with protection class IP-X4/IP54. VCB should be of indoor class with 3 pole/Phase, Rated voltage 6.6 kV±10%, Rated insulation level 7.2 kV Rated normal current 800 Amp, Rated short circuit breaking current/ capacity 26 KA/ 300 MVA in 3secs, rated operating Sequence 0-0.3sec-CO-3min-CO, consisting of manual cum motor operated spring charged mechanism of stored energy type. In the closed state of breaker, the closing spring can perform the duty operation. Facility should also be available for hand charging the springs in the event of control supply failure, Spring charging motor shall be rated for 230VAC, 50 HZ supply. Electrical anti-pumping feature should also be provided. The VCB shall consist of three air insulated poles incorporating mechanism of interrupters. Power supply for tripping devices of the breaker shall be fed from DC source Power supply for tripping / closing devices of the breaker shall be fed from 110-volt DC source. Master control switch TNC trip, neutral, close switch for VCB control shall be provided. Indicating lamps shall be “Cluster LED” type Lamps having minimum power consumption, Inside the cubicles the wiring for control, signaling, protection and instrument circuit shall be done with PVC insulated conductors. The wiring shall preferably be enclosed in plastic channels or neatly bunched together. The CT wiring shall be minimum 2.5sq.mm. And other control as well as PT wiring shall be of 1.5sq.mm. The same shall be of multi-stranded copper. Each wire shall be identified at both ends by PVC ferrule. The instrument transformer such as current and voltage transformer shall be cast resin insulated. The current transformer shall conform to latest edition of IS 2705, while the voltage transformer shall conform to IS 3156. The CT’s and PTs shall be designed suitably for required metering and protection equipment. The line PTs shall be single/three pole version. Digital Ammeters shall be provided on each Breaker panel with suitable selector switches of standard make and quality. Digital Voltmeter of PTR 6.6 KV/110 V shall be provided on VCB Panels with suitable selector switch of standard make and quality. All breakers shall be provided with Digital/ Numerical type motor protection Relays as per the requirement, over current Relay, Earth fault Relays with IDMT (Inverse Definite Minimum Time) for outgoing feeders and all other such Relays as may be required for the best protection practice shall be supplied by the vendor. All shall be Digital/Numerical relays of good quality and manufactured by a renowned manufacturer. The panel is to be installed in alignment and circuit connections of already installed incomer panels, bus bar coupler & auxiliary panels including required modification in bus-bar/ cable connection as per site conditions. The job includes shifting/storing the existing/old panel to sub-divisonal rajal store Complete job shall be done as per all specifications, parameters and provisions as per the scope of work. The job includes cost of material, transportation charges also dismantling charges with storing, labour charges for skilled and semi skilled workers for execution of job/handling the components with hire charges for deployment of tools and tackles at site. The job includes testing, commissioning on no load and then on full load . complete job