CB synchronization supervision recognizes states where not all circuit breaker contacts are open or closed. This function uses both current flow monitoring and evaluation of CB status signals to detect CB synchronization. In order to bridge CB operate times the time delay CBF_1: Delay/CB sync.superv can be used. When this time delay has elapsed the signal CBF_1: TripSig CBsync.super is issued. Poles that are recognized as being ‘open’ will still be signaled.