Antipumping Contactor use

Dear Sir

The use of anti pumping relay / contactor is to ensure that the breaker closing coil receives only one closing impulse.It does not allow continuous closing command to the breaker in case the TNC switch is held in the position of "close" continously.

For further details studying the manufacturer's closing circuit scheme of a breaker will be very helpful.

Hope the same is clarified.

regards

If you give the breaker a close command and the breaker fails to latch in the closed position , it will drop back to the open position.

Another reason why a breaker will do this is if there is a trip command present to the breaker.

The purpose of the anti-pimping relay or contactor is to prevent the breaker from trying to reclose every time it drops back to the open position even though you hold the close switch in the close command position.

This prevents severe wear to the breaker mechanism and contacts.

To give a second close command , you need to release the first command and make another atempt to close the breaker.

On a persisting fault , if a continuous closing command is maintined on an electrical circuit breaker , the breaker will first trip and then reclose due to the continous closing command . This is termed as " pumping of breaker .

This will result in considerable damage to system ( due to continous O-C-O-C operation)

To prevernt such pumping operation an antipumping device is used . This ensures

that breaker with continous closing commannd , once tripped , wlill not againg closed again unless closing command is withdrawn and deliberate closing commnad is given subsequently .

Antipumping is geneally provided by electrical interlocks..It involves an ausillary contactor or a relay .

Vikash Agrawal

Crompton greaves

Nasik

Sir,

NC contact of the Anti Pumping relay(K2) is back feeded

to the Closing coil so that when K2 is Picked

NC becomes NO and Closing Coil of The breaker is isolated

and O-c-O-C opeartion of the Breaker is prevented in the process .even when the

closing switch pressed continuously, for a period of time.

regards

Brijesh Ojha

Reliance Ind Ltd.