ABB REF 545 Back Up Protection Relay

[fb599]

Has anyone had a failure of this type of relay that could have possibly issued an "open" command to a circuit breaker without receiving such an instruction ?

Any help welcomed.

 

[nraju]

fb599 -

Is your REF545 an SCU (Switchbay Control Unit)? We have ABB's REF542 which is an SCU and have had one such incident in the past. Please give more details of REF545.

 

[fb599]

Thanks for the early reply. Yes, this REF 545 is providing back up protection to a circuit but it also controls the circuit breaker too. ie remote control and MMI local control.