Toshiba GR-200 Series Instruction Manual page 136

6F2T0200 (0.15)
Broken conductor protection (BCD)
A series fault or an open circuit fault can be caused by circuit breaker contact failure, the
operation of fuses, and false operation of single-phase switchgear. IEC60050 defines a series
fault as having impedances in each of three-phases that are not equal; hence, the series fault
is typified by the interruption of one or two phases, as a rule. The function of broken conductor
protection (BCD) is to detect series faults and signal a trip signal to the trip circuit.
GRE200 (1,2)
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