Anti Pumping Relay And Its Operating Principle 102s1r

Anti Pumping Relay and its Operating Principle It is a device in the circuit breaker that prevents multiple closures of the breakers. Multiple breaker closures can damage the closing mechanism of the breaker. The antipump function is a very important feature of control circuits. Without the anti-pump function, if the connected a maintained in the close circuit, and the circuit breaker were closed into a fault current, the protective relays would cause an immediate trip action, but the maintained in the close circuit would initiate closing (again) into the fault. This process is called pumping, and would lead to ultimate catastrophic failure of some element in the system, perhaps the conductors leading to the fault, perhaps the circuit breaker, or elsewhere in the system. Therefore, anti-pump control is one of the fundamental requirements for every medium-voltage circuit breaker. Anti-pumping relay is used to prevent multiple breaker closures. The effect of continuous closing of circuit breaker is called breaker hunting effect. Anti-pumping relay insures that the breaker closes only once and removes the hunting effect of the breaker. It is also called trip free mechanism of the circuit breaker. Sometimes anti-pumping relay is built-in in the circuit breaker and sometimes it works as auxiliary relay with circuit breaker. Note that the anti-pump function is reset if the control power supply is removed for some reason. When this happens, the anti-pump relay in the close circuit closes to complete the close circuit. Then, if a maintained in the ’s control circuit is closed, and the control power is restored, the circuit breaker will close. However, after this initial close operation, the anti-pump relay will be sealed in, and further closing operations will be prevented until the maintained is opened or the control power supply is interrupted. Multiple closure of circuit breaker can cause damage to breaker and it can be avoided by using 52 relay (circuit breaker anti-pumping relay). The main function of this relay is to cut off the supply to 52C (circuit breaker closing coil) coil in case of TNC (trip neutral close push button) switch spring failure and prevent multiple closure of circuit breaker (hunting effect of CB). Trip coil along with anti-pumping relay Closing coil circuit with 52 present is as shown in above figure below. Path 1 in the figure shows how 52C (CB closing coil) will be energized when we press TNC switch. If switch comes to its original state once we release it then 52 will not come in picture. If switch

does not comes to its original state then 52 will be energized as shown in path 2. Then 52-NC (normally closed) present in path 1 will be got opened up and prevents extension of supply. The auxiliary s and anti-pumping relay s are shown in the figure with blue arrow.

We have the concept that initially for the energization of 52 80% to 90% of 110V is required. But once after energization 60-70% of 110V is sufficient to maintain its energization state. This logic is achieved by introducing a resistance in 52 energization maintenance path.

Trip-free mechanism or anti-pumping control is an important safety feature, as it assures that the decision to open a circuit breaker dominates over the command to close.