Toshiba GR-200-5 Instruction Manual page 136

6F2T0207 (0.01)
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 (5,6)
- 116 -