ABB RELION Series Technical Manual page 476

Section 5
Protection related functions
470
active for the time set with the Trip pulse time setting or the time the circuit
breaker is in the closed position, whichever is longer.
• If CB failure mode is set to "Both", TRRET is activated when either of the
"Breaker status" or "Current" mode condition is satisfied.
• If CB fail retrip mode is set to the "Without check" mode, TRRET is activated
once the timer 1 is activated without checking the current level. The TRRET
output remains active for a fixed time set with the Trip pulse time setting.
The activation of the BLOCK input or the CB_FAULT_AL output deactivates the
TRRET output.
Timer 1 elapsed
From Timer 1
CB fail retrip mode
"Without check"
CB fail retrip mode
"Current check"
CB failure mode "Current"
CB failure mode "Breaker
status"
CB failure mode "Both"
I >
From Level detector 1
POSCLOSE
CB_FAULT_AL
From Timer 3
BLOCK
GUID-BD64DEDB-758C-4F53-8287-336E43C750F2 V2 EN
Figure 241: Retrip logic
Backup trip logic
The backup trip logic provides the TRBU output which can be used to trip the upstream
backup circuit breaker when the main circuit breaker fails to clear the fault. The
backup trip logic is activated by the timer 2 module or timer-enabling signal from the
start logic module (rising edge of the START input detected), and simultaneously
CB_FAULT_AL is active. The operation of the backup logic depends on the CB
failure mode setting.
• If the CB failure mode is set to "Current", the activation of TRBU depends on the
CB failure trip mode setting.
• If CB failure trip mode is set to "1 out of 3", the failure detection is based
on any of the phase currents exceeding the Current value setting. Once
TRBU is activated, it remains active for the time set with the Trip pulse time
setting or until the values of all the phase currents drop below the Current
value setting, whichever takes longer.
• If CB failure trip mode is set to "1 out of 4", the failure detection is based
on either a phase current or a residual current exceeding the Current value
or Current value Res setting respectively. Once TRBU is activated, it
AND
OR
AND
AND
OR
1MRS758755 A
AND
OR
AND
AND
REC615 and RER615
Technical Manual
TRRET