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Electrical Control Panels
 

PRODUCT INFORMATION   007

AUTOMATIC - ON- MAINS FAILURE CONTROL PANEL FOR
3-PHASE DIESEL ALGENERATOR SETS

GENERAL

The AMF type control cubical is designed to be used in conjunction with diesel-alternator sets comprising of diesel engines and electric alternators for providing a stand by source of emergency power suitable for automatic -on- mains failure type of duty. The control system provides for both automatic on mains failure as well as for manual operation.

 

SYSTEM OPERATION

The emergency diesel-generator set will function as follows :  -

 

AUTOMATIC MODE

While the normal mains supply is healthy the diesel alternator set will be at rest and the mains will supply the load.

A line voltage monitor relay monitors the main supply voltage and if the mains supply fails or if the mains supply voltage drops below a certain present value, for a period exceeding 5-10 Sec., start-up of the diesel engine is initiated.

When the diesel-alternator set reaches its operating voltage a signal is given for the closing of the alternator contactor / breaker.

When the mains supply is restored, its quality is monitored for a short duration and if proven satisfactory, the load is automatically transferred to the mains supply and the diesel alternator set is shut down.

The alternator set now supplies the load.

The diesel alternator set reverts to its standby condition and is ready to start should the mains fail again.

 

MANUAL MODE

The manual mode of operation, as selected on the unit mode selector switch, is different from the automatic mode in that the diesel alternator set has to be started manually by the operator by pressing the "START" push button.

Alternator contactor / breaker closure after the set reaches rated speed and voltage has to be done manually by pressing the "CLOSE " push button. Tripping is also manual through the "TRIP" push button.

The engine has to be shut down manually by pressing the "STOP” push-button.

 

TEST MODE

The test mode of operation, as selected on the unit mode selector switch is very similar to the automatic mode.

Mains supply failure condition is stimulated by holding the "TEST" push button pressed for about 1-5 seconds. The sequence of events will be as described in paragraphs 2.1.2 to 2.1.6.

 

UNIT PROTECTIVE FEATURES

The diesel engine will have the following protective features:  -
  • FAILURE TO START

  • HIGH COOLING WATER TEMPERATURE               

  • LOW LUB-OIL PRESSURE

The alternator will have the following protective features: -

  • Overload protection using Thermal O/L Relay. 

  • Short circuit protection using HRC Fuse /MCB/MCCB

  • Other protections built into the ACB, if used.