GUID-1A2C47ED-0DCF-4225-9294-2AEC97C14D5E V1 EN
Figure 390: Timeline of the breaker failure protection
Timer 3
This module is activated by the CB_FAULT signal. Once activated, the timer runs until the
set CB fault delay value has elapsed. The time characteristic is according to DT. When the
operation timer has reached the maximum time value CB fault delay, the CB_FAULT_AL
output is activated. After the set time, an alarm is given so that the circuit breaker can be
repaired. A typical value is 5 s.
Retrip logic
The retrip logic provides the TRRET output, which can be used to give a retrip signal for
the main circuit breaker. Timer 1 activates the retrip logic. The operation of the retrip logic
depends on the CB fail retrip mode setting.
• The retrip logic is inactive if the CB fail retrip mode setting is set to "Disabled".
• If CB fail retrip mode is set to the "Current check" mode, the activation of the retrip
output TRRET depends on the CB failure mode setting.
• If CB failure mode is set to the "Current" mode, TRRET is activated when the
value of any phase current exceeds the Current value setting. The TRRET
output remains active for the time set with the Trip pulse time setting or until all
phase current values drop below the Current value setting, whichever is longer.
• If CB failure mode is set to the "Breaker status" mode, TRRET is activated if the
circuit breaker is in the closed position. The TRRET output remains active for
1MAC059074-MB A Section 5
Protection related functions
615 series ANSI 777
Technical Manual
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