ITC of new 1 MVA Transformer and allied EI work at Hospital area of COM and JNM Hospital Kalyani Nadia.

Supply, delivery with installation of 3 Phase, 50 Hz, Delta / Star,1000 KVA, 11/0.415 KV, Cast Resin, dry type, copper wound, Transformer suitable for indoor installation having the following specification as per IS 11171-1985 & IS - 2026 with latest modification (if any) & CBIP Specification [Make: ABB/Schneider/Crompton]. Links/Tapings: Off circuit Links, tapping range + 5 % to - 5 %, in steps of 2.5 % Tap position, Cooling: Air Natural (AN), Painting: Epoxy-based (as per IS-5/RAL7032), Vector Group: Dyn 11 Flux density 1.7 Tesla at 100% rated voltage, 1.9 Tesla at 112.5% rated voltage. Current density 3 amp/sq. mm for HV & LV winding. Tapping on HV winding off circuit + 5 % to - 10 % in 2.5 % steps. Design Clearances 11 kV system Phase - Phase 180 mm and Phase – Earth 120 mm, 415 V system Phase - Phase 25 mm, Phase – Earth 25 mm. One-minute power frequency withstand voltage: 3 kV for 415 V systems and 28 kV for 11 kV systems. Lightning impulse withstand voltage: 75 kV peak for an 11 kV system. Short Circuit withstand level - Three-phase dead short circuit at secondary terminal with rated voltage maintained on the other side - For 3 sec. Radio Influence Voltage - Maximum 250 microvolts. Harmonic currents - Transformer to be designed for suppression of 3rd, 5th, 7th harmonic voltages and high frequency disturbances.

Plate/corrugated/tank features: (a) Adequate for meeting mechanical & electrical withstand requirements, as per applicable standard, (b) The tank and its sealing (gaskets, o-rings, etc.) shall be of adequate strength to withstand positive and negative pressures built up inside the tank while the transformer is in operation. The maximum pressure generated inside the tank should not exceed 40kPa, positive or negative, (c) Corrugated fins shall be built up of CRCA sheets of a minimum 2 mm thick. d) The corrugated tank wall shall ensure sufficient cooling of the transformer and compensate for the changes in the oil volume during operation. e) The transformer shall be capable of giving a continuous rated output, without exceeding the specified temperature rise. f) Internal clearance of the tank shall be such that it facilitates easy lifting of the core with coils from the tank and HV & LV bushings mounted on the Top cover. Class of Insulation: Class F, Temp. Rise: 90 °C over ambient of 50°C. Core & Coils: The core shall be built up with high-grade, non-ageing, low-loss, high-permeability, cold-rolled grain-oriented silicon steel laminations, especially suitable for core material. Grade of core should be M4 or better. The coils shall be manufactured from electrolytic copper conductor & fully insulated for rated voltage, coils shall be resin moulded for both LV & HV with epoxy resin, encapsulated, Class F, naturally cooled (AN).

Core design features:a) Magnetic circuit designed to avoid short circuit paths within core or to the earthed clamping structures. b) Magnetic circuit shall not produce flux components at right angles to the plane of lamination to avoid local heating. c) Least possible air gap and rigid clamping for minimum core loss and noise generation. d) Adequately braced to withstand bolted faults on secondary terminals without mechanical damage and damage/ displacement during transportation and positioning. e) Percentage harmonic potential with the maximum flux density under any condition limited to avoid capacitor overloading in the system. f) All steel sections used for supporting the core shall be thoroughly sand blasted after cutting, drilling, welding. g) Provision of lifting lugs for core coil assembly. h) Supporting framework designed not to obstruct complete drainage of oil from transformer Winding materils: Electrolytic Copper.Maximum Current Density allowed-Maximum 3 amp / sqmm or its better.

Insulating material shall be proven design & should be selected in such a way that the transformer will be capable of supplying 110 % continuous load. Coils shall be so insulated that impulse & power frequency voltage stresses are minimum. Coil assembly shall be suitably supported between adjacent sections by insulating spacers & barriers.All leads from the windings to the terminal board & bushings shall be rigidly supported to prevent injury from vibration or short circuit stresses. Guide tube shall be used where practicable. The core and coil assembly shall be securely fixed in position so that no shifting or deformation occurs during movement of transformer or under short circuit stresses. Transformer losses shall be guaranteed as below : Maximun loosses at 50 % loading : 2.8 KW Maximun loosses at 100 % loading : 7.25 KW. Transformer losses shall be guaranteed on maximum basis i.e. without any positive tolerance. Efficiency (Minimum): % efficiency at 75 deg C/ unity P.F. a) At 100 % load: 98.56 Impedance: 4.5 % (Allowable tolerance as per IS) % Regulation : a) At 100 % load with Unity PF: 1.22 b) At 100 % load with 0.8 PF: 3.53 Testing: All Routine tests as per relevant IS have to be conducted at manufacturer’s works. Terminal arrangement: HV cable box assembly with copper flat & support insulator. LV cable box assembly with copper flat, Aluminium Gland plate & support insulator.

The Transformer will be of Environmental Class E2 (Minimum), Climatic Class C2 as defined IEC 60076, Fire Behavior Class F1 as defined in IEC 60076-11. All the above i.e. Environmental Class, Climatic Class & Fire Behavior Class must be indicated in rating plate. Enclosure: Sheet steel with protection class IP-33, painting should be epoxy/as per the latest standard. Basic level Insulation for HV: 75 KV pk. Temperature Scanner: Provided with 3 RTDS for sensing winding temperatures along with temperature scanners for display of winding temperature, and with Alarm / Trip contacts. Testing: All Routine Tests as per the relevant IS will be conducted at the manufacturer's works.

Supply, delivery and installation of LT Cubical type floor-mounted panel board with multi Compartments: one for incoming, one for busbar (Vertical) and others for outgoing MCCBs, made with 14 SWG CRCA Sheet. Cable chambers in the panel should be of adequate width along the vertical height, and the required number of cable chambers to be provided in the panel so that outgoing cables do not pass through any other main switch or bus bar. The Panel should have required lifting hooks. All doors should be hinged type door with a railway-type locking arrangement. A rare cover door should be provided for inspection of the Bus bar and easy cabling. All openings shall be properly gasketed. The panel board should have a proper cable alley on both sides with cable entry at the bottom and detachable Gland Plate. The board should be painted with powder-coated paint. The Panel board consists of the following accessories:

Incoming : 415 V 415 A on-load front-operated FP Changeover Switch (Make: Schneider /L&T / Siemens) - 1 No. Bus Section: 415 V, 600 A pure copper bus bars for Ph. & N. (Size of bars - 50 mm x 8 mm). The bus bar shall be fixed with FRP chairs & the entire bars are insulated with PVC heat shrinkable sleeves of suitable size & different colours as per norms/direction of E.I.C. All interconnections should be done with appropriately sized copper bars. Outgoing Arrangements: - A) 415 V, 50 HZ, FP, MCCB (Make - Siemens/L&T/Schneider) including spreader link, extended rotary handle with the following ratings and quantity: a) 200 A - 2 Nos., b) 160 A - 2 Nos., c) 63 A - 2 Nos. All SFUs should be connected with the required size/equivalent rating Copper flat (B) 415 V 63 A TPN Contactor (Make: Schneider/L&T/Siemens) - 2 Sets (C) Digital Timer (Make: Schneider/L&T/Siemens) - 2 Sets (D) 415 V 63 A TP Auto-Bypass Toggle Switch - 2 Sets

Metering, Control & Indication Arrangement :- a) Multifunction Meter Digital Type Load Monitor (Make: Schneider/ABB/Schneider/as per approval from EIC) - 1 No b) CT, 400/5 A (Make - Kappa/or appeove from EIC) - 3 nos.. c) Indicating LED lamp with colour glasses showing Red/Yellow/Blue (Make - Schneider/ ABB/ Siemens / as per approval from EIC) - 6 Sets. d) 6 A SP MCB - 6 nos. (F) Danger Board 16 SWG (16" x 12") - 2 Nos. All interconnections from incoming to busbar and busbar to outgoings are to be connected with suitable size of Cu bars as per direction of EIC The complete panel board is to be installed on a suitable brick and C-type Iron pedestal as directed by the E.I.C.

Making a hollow brick wall and an iron C-channel foundation, and brick soiling for installation of the 415 V, 1600/1200 A, LT, cubical panel on that brick foundation, incl. plastering and net cementing the wall and floor as per the direction of EIC.

Shifting and installation of the existing 1200 A LT panel after disconnection of all outgoing cables (different sizes), reconnecting the same with necessary civil works and all other necessary arrangements as per the direction of EIC.