ABB REF 542plus - Page 68

Note: When the primary object in such an undefined positions, issuing an open
command will activate the open coil on the circuit breaker. The open operation is
never blocked. The close operation with the object in the undefined position is
blocked. A close command will be discarded and will turn the interlocking error
LED on.
68
REF 542plusREF 542plus
Multifunction Protection and Switchgear Control Unit
Operator's manual
1MRS755869