1. Vindhyachal super thermal power project is located in Singrauli district of Madhya Pradesh. Nearest railway station is Shakti Nagar
(03 Kms approx.) and nearest major town is Varanasi (220Kms Approx.).
2. The subject DC system is required for CHP#1 HT switchgear which fed the power to the electrical equipments of coal handling
plant (stage#1) which caters to the coal requirement for six units of 210MW each.
3. The scope of work consists of 02 parts as mentioned below-
Part #A (10.10) Design, manufacturing & supply of 01 no DCDB panel, 02 nos Battery banks, 02 nos Battery chargers and other
required accessories (Vendor to visit our site for detail engineering & other assessment for carrying out the job properly.)
Part- B (20.10) Erection, testing & commissioning charges for DC system
4. DCDB: DCDB shall be indoor, air insulated, free standing type, totally enclosed, dust/vermin proof and floor mounting type made
of CRCA sheet steel (2mm). DCDB will have 02 nos 160A SFU/MCCB Incomers from battery charger, one 125A SFU/MCCB Bus
Coupler, 02 nos 125A SFU/MCCB incomers and 22 nos 63A outgoing feeders (11 nos each for both sections)
5. Battery Bank:
Ø Rated Capacity (C5) # 410 AH for 03 hrs discharge (Battery aging factor & temperature correction included)
Ø Nominal Voltage # 220V DC
Ø Battery type - Stationary Nickel-Cadmium Pocket Plate High discharge type (KPH)
Ø Nominal Voltage per cell # 1.2 VPC
Ø Calculated ECV # 1.14V
Ø Float Voltage # 1.4-1.42 VPC
Ø Boost Voltage # 1.7 VPC
Ø Codes & standards # IS 10918, IS 1069, IS 1652, IS 1146
Ø Ambient temperature # 50 Deg C
Ø Relative humidity # 85 %
6. Battery Charger
Ø Rating: 415V AC, 50 Hz, 3Ph 4Wire, 220V DC, 90A DC
Ø Power Conversion: AC to DC by means of a three phase full wave Full controlled rectifier consisting of thyristors.
Ø Output voltage regulation: ± 1% of set value for ± 10 % input voltage variations
Ø Ripple Voltage: less than 1% peak to peak
Ø The battery chargers shall be provided with static type automatic voltage regulators. The system shall have two separate float cum
boost charger. Normally both the charger will be operated in float mode and take care the load. If boost charging is required by the
battery, it has to be initiated manually. In this boost mode the charger should charge the battery bank at constant current mode, so that
it can get back its fully charged state as soon as possible. The interlocking should be provided with DCDB incomer using suitable
relay for disconnecting the load during boost charging. When one FCB in boost mode, the other FCB will supply the load & for this to
happen bus coupler should be in on position.
Ø The charger can be operated in manual mode by selecting the Auto/Manual selector switch and the output voltage can be varied by
operation of respective potentiometers. Normally the charger will operate in float mode in auto position.
7. Unloading, shifting and custody of the materials will be done by party until total package is handed over to NTPC after complete
erection, commissioning, testing, normal running of the total system. However NTPC will provide transportation facilities i.e Track/
Hydra or other lifting equipment free of cost within the plant premises.
8. Party should supply (if required) all the necessary components like iron channel, bends, angles, insulators, bus bars, connecting
cables for erection, commissioning & testing work.
9. Fabrication of base plate, cable entry hole as requirement to be done by the party.
10. All power & control cable connections after new panel erection to be done by the party.
11. Any type of modification work i.e cutting, welding, grinding, and making holes, sealing holes, foundation work, civil work
including platform making etc required for the erection & commissioning work will be done by the party.
12. All kinds of Pre-commissioning / post-commissioning tests and quality checks to be performed by the party as per approved
quality plan (QAP).
13. Detailed drawing (Electrical, general arrangement & mechanical) & manual (four sets of each) are to be submitted by the vendor.
The drawings are to be approved by NTPC.
14. Supply of one complete set of all types of mandatory spares required for smooth running after complete handover.
15. All quality checks / testing will be inspected by NTPC as per approved quality assurance plan (QAP).
16. Coverage of Contract: The contract is a complete one for labour and materials, with the contractor#s overhead and profits, to &
fro transportation, including the provision and use of various equipments, tools, tackles, etc. required completing the work. The
various obligations of the contractor under the contract shall be at the cost of the contractor.
17. Duration of work: 03 months