Operation P54x/EN OP/La4
MiCOM P543, P544, P545 & P546
(OP) 5-189
OP
Figure 119 Auto-relose timing diagram leader/follower (3ph)
5.6.6 Auto-reclose : main operating features (P544/P546)
5.6.6.1 Circuit breaker in service (P544/P546)
The ci
rcuit breaker in service logic is shown in AR Figure 4 (logic diagram supplement).
To be
available for auto-reclosing, each circuit breaker has to be in service when the auto-
reclose is initiated by a protection operation. The circuit breaker is considered to be in
service if it has been in a closed state for a period equal to or greater than the setting
CB IS Time.
A short adjustable time delay, CB IS Memory Time, allows for situations where, due to very
fast acting circuit breaker auxiliary switches, when a circuit breaker trips following a fault, the
circuit breaker change of state from closed to open is detected in the auto-reclose initiation
logic before the AR Initiate signal from the protection is recognised.
Once an auto-reclose cycle has been started for the relevant circuit breaker, the in service
signal for that circuit breaker stays set until the end of the auto-reclose cycle.
The Bx In Service (x = 1 or 2) signal resets if the circuit breaker opens, or if the
corresponding circuit breaker auto-reclose in progress (ARIP) signal resets.
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