Specification Electrics

Controls

  1. Electric Motor driven fire & jocky pumps & diesel engine driven fire pump shall start automatically through preset pressure switches in proper sequence as elucidated in Cl. 4.2 above.
  2. Stopping of all fire pumps shall be manual only.
  3. Audio visual alarm shall be sounded when fire pumps start/starts.
  4. Power supply 'ON' indication shall be provided in the Fire Pump Control Panel.

A C Motors

All A C motors shall be approved type & totally enclosed fan cooled and shall have Class B insulation with degree of protection IP 55 conforming to IS 325 and frame. All motors shall be suitable for both DOL and STAR/DELTA starting, as required. The motor terminal box shall be suitable for receiving aluminium cables and suitable for positioning on the motor body at intervals 90 degree as required for the particular application. The motors shall have also two distinct terminals for earthing. All the motors shall be suitable for 415 V (- 15% to + 5% variation) 3 phase 50 HZ plus minus 3% AC supply.

Motor Control Centre (M C C)

The M C C shall be made of sheet steel of thickness not less than 2 mm, totally enclosed, self supporting, floor mounted dust and vermin proof cubicle type construction with multitier compartmental arrangement with degree of protection IP 54. It shall have a series of panels of uniform height placed side by side with front access for operation as well as cabling. MCC panel shall be completely front wired type having all device/termination etc, approachable from front without any requirement of back access for maintenance repairs and cabling. Provision of cable entry shall be from the top or bottom to match with cable layout of the pump room.

Main fire pump motors shall have star/delta or DOL starting as per TAC requirement. The motor control circuit shall be provided with test facilities so that it is possible to test the control circuit with the main motor circuit disconnected. Control voltage shall be 240 V, A C single phase derived from an isolating transformer.

The main busbar of the M C C shall be of electrical grade copper and shall have continuous current rating as required but in no case less than the current rating of incoming switch fuse unit. The busbars shall be easily accessible from the front of the cubicle and shall be colour coded as per IS for phase identification. An copper earth busbar of adequate cross sectional area shall be provided in the bottom or top part of the cubicle and shall run for the entire length of the MCC.

Start/stop push button, auto/manual selector switch and indication shall be provided and the MCC for control of the motors. Incomer cubicle shall incorporate voltmeter, ammeter with respective selector switches, power factor meter and phase indication lamps. Each outgoing cubicles shall have ammeter with selector switch and on/off, trip indication lamps. Ammeters for incoming/outgoing cubicles, for motors it shall be supressed scale type beyond full load rating upto 8 times of full load current for taking care of starting current kicks.

Diesel Engine Control Panel

The control panel shall be made of sheet steel of thickness not less than 2 mm, totally enclosed, self-suporting, floor mounted, dust and vermin proof cubicle type with degree of protection IP 54. The following features shall be incorporated in the control panel :

  1. Contactors, relays, timers etc for applying automatic starting pulses to the diesel engine on receipt of a command signal from the pressure switch with starting sequence consisting of three electrical pulses of 5 second duration each spaced at 5 second apart.
  2. Main ON/OFF isolator with DC circuit fuses and main ON indication.
  3. Boost cum trickle automatic battery charger with fuse protection for AC charging circuit (trickle/boost), Auto/Manual selector switch for charging, charging current meter, volt meter etc.
  4. Indication/Alarm for the pump "RUN" condition, Annunication for engine fault condition, alarm cut off switch and reset switch for fault conditions.
  5. Engine start switch, engine stop switch together with Auto/Manual switch for engine starting and indication showing failure to start on 'AUTO'.
  6. Engine RPM indication from in built tachometer with engine.

Cables

All power cables shall be multi core, 1100 V grade, PVC insulated, PVC sheathed, aluminium conductor cables manufactured and tested as per IS 1554 and ISI marked.

All control cables shall be multi core, 1100 V grade, PVC insulated and overall PVC sheathed with copper conductor manufactured and tested as per relevant IS and ISI marked. Armoured power and control cables shall be only considered.

Installation accessories and earthing materials

One lot of installation accessories and earthing material shall be installed for equipment and cables and earthing of equipment.

Power supply

For M C C one 415 V, A C 3 phase and neutral 50 HZ feeder of adequate capacity shall be made available at the M C C incomer. If the equipment is required to operate at any other voltage, necessary transformers & converters shall be included in the scope of the tenderer.

 
     
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