ABB RELION REX640 Technical Manual page 1079

1MRS759142 C
REX640
Technical Manual
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(OR)"
I >
From Level detector 1
POSCLOSE
OR
AND
CB failure mode "Both(AND)"
CB_FAULT_AL
From Timer 3
BLOCK
GUID-3E9EF062-CE57-4E62-A98F-9682F1F93390 V1 EN
Figure 576: Retrip logic
Backup trip logic
Timer 2 activates Backup trip logic, which gives a backup trip TRBU for the upstream
circuit breaker if the main circuit breaker fails to clear the fault. Backup trip logic is
also activated if the timer-enabling signal from the Start logic module (rising edge of
the START input detected) and CB_FAULT_AL are both active.
The operation of Backup trip logic depends on the settings CB failure mode and CB
failure trip mode as shown in
Table 1010: Backup trip logic operation
Value of setting CB Value of setting CB
failure mode failure trip mode
Current 1 out of 3
1 out of 4
2 out of 4
Table continues on next page
Protection related functions
AND
AND
AND
AND
OR
AND
AND
Table 1010.
Conditions for activating Backup trip logic
Any phase current exceeds
Either of the following is true:
• Any phase current exceeds
setting.
• The residual current exceeds
Res setting.
Either of the following is true:
• Any phase current exceeds
setting and the residual current exceeds
Current value Res setting.
• Two or three phase currents exceed
value setting.
Section 5
OR
TRRET
AND
Current value setting.
Current value
Current value
Current value
Current
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