switchgear

The anti pumping circuit prevents to send closing command and energizing of closing coil while the breaker is closed.

The anti-pump (52Y) relay prevents the breaker from closing more than once on one close signal. For example, you use the local control switch to close the circuit breaker. There is an existing fault on the line, and the circuit breaker trips on overcurrent. If you have not released the switch (or the contact is stuck), the control circuit will tell the breaker to close again, right into the fault, which will cause the breaker to trip, but then the breaker will close again, a never-ending circle resulting in serious damage and much repair work. To prevent this, the 52Y relay "locks out" the closing coil until the close signal is removed.

The 52Y relay is energized at the same time, and through the same source, as the closing coil. The 52Y relay has a normally closed contact in series with the closing coil. As soon as the breaker closes, the NC contact opens and prevents the closing coil from being energized again. Once the close signal is removed (in this case by releasing the control switch), the 52Y relay is deenergized, closing its NC contact and allowing the breaker to close upon receipt of a new close signal.