Anti-pumping Contactor

Anti pumping contactor prevent reclosing the breaker. It will block the re-closing pulse.

They have a relay in the control circuit so that if tripped, the closing circuit can not be continuously energized. This keeps someone from holding the close button in, closing the breaker back in on a fault where it would re-trip then the closing button being held in, would close the breaker back in on the fault where it would then trip but the closing button is still held in so the breaker would close back in on the fault then trip but the closing... This is the "pumping", the anti-pump feature is a common feature on large breakers. Smaller breakers have a "trip free" feature which performs a similar function, you can not prevent them from tripping by simply holding the operating lever in the close position.

The anti-pump relay provides a logic function for the control circuit which prevents a continuous electrical close signal from causing the circuit breaker to continously reclose after a trip signal

The anti-pumping circuit in the Electronic Charging Motor Controller (ECMC) of the Siemens Electric Motor Operator is to prevent a maintained close signal from repeated attempts to re-close the breaker after a fault. Without the anti-pump feature, as soon as the breaker tripped the motor operator would re-close the breaker, the breaker would immediately trip again and the cycle of tripping and re-closing would continue until the breaker was destroyed

what i feel is , breaker cannot close itself until the TNC switch is held at close position continuosly and hence the closing pulse is given continuosily. the reason why antipumping is given is that as the closing coil is not heavily rated for carrying current continuosily, and it would rather burn if closing pulse is given continuosly, so in order to prevent closing coil from burning this antipumping relay contact is latched in closing ckt. so that it does not recieve closing pulse continuosily if once energized in normal condition.