Protection Pickup

Before the protection system can operate to trip the circuit breaker, a protection pickup must occur. A pickup condition occurs when a measured quantity (For example, current, voltage, frequency and so on) has exceeded a threshold setting. A protection pickup can sometimes initiate a protection trip instantaneously that is without any intended delay. Or it can start a trip timer and cause a protection trip after that timer expires.

If the protection is in the pickup state and a trip timer is running, providing the condition that caused that pickup remains constant, a protection trip must eventuate at some point.