{TAIL ~ an OR gate} for receiving the power supply interrupting signal and {HEAD ~ the breaker opening command}, and for producing an output signal indicating that the breaker is to be opened when either one of the power supply interrupting signal and the breaker opening command is received; and 
{ TAIL ~ an OR gate } for receiving the power supply interrupting signal and { HEAD ~ the breaker opening command } , and for producing an output signal indicating that the breaker is to be opened when either one of the power supply interrupting signal and the breaker opening command is received ; and
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH