Toshiba GR-200 Series Instruction Manual page 157

fault in response to the "re-trip" command, OCCBF and EFCBF would reset and the CBF
sequence is stopped.
If the target CB were to fail to remove the fault with the "re-trip" command, and if
OCCBF or EFCBF continued to operate and if the timer #2 were to time out in accordance with
the setting time applied [TCBF-TP], CBF will issue a trip command to the adjacent CB(s) to
clear the fault, as a last resort.
Scheme logic
2.12.4
CBF function can issue a trip signal in each phase. The trip signal will be generated where
OCCBF or EFCBF element is being operated and signals 'GEN.TRIP-*'† are generated
constantly. In other words, the circuit breaker has not been opened successfully with the
GEN.TRIP-* so that the fault has not been cleared yet; therefore, CBF trip command is
required separately.
†Note: The IED issues GEN.TRIP signals in trip circuit function (TRC), which is
discussed in Chapter 2.23.
When wishing to issue the CBF trip command without the GEN.TRIP-* commands, the
IED can issue it with external signals come from other relay devices. The user should inject
the external signals at PLC connection points 'EXT.CBF_START*'.
On the other hand, when wishing to issue the CBF trip command without the operation
of OCCBF or EFCBF element, the IED can also issue it with external signals using PLC
connection points 'SUB.CBF1*'. This technique will be achieved when the user programs to
inject a 'CB close (closed) state signal' at the 'SUB.CBF1*' points. It is useful if the CBF
function cannot determine the conditions of breaker failures, when OCCBF element fails to
detect small fault currents.
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6F2T0200 (0.15)
GRE200 (1,2)