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Value of setting CB
failure mode
Value of setting CB
failure trip mode
Conditions for activating Backup trip logic
• Two or three phase currents exceed
Cur-
rent value
setting.
Breaker status
1 out of 3
1 out of 4
2 out of 4
CB is in closed position.
Both(AND)
1 out of 3
CB is in closed position and any phase cur-
rent exceeds
Current value
setting.
1 out of 4
CB is in closed position and either of the fol-
lowing is true:
• Any phase current exceeds
Current value
setting.
• The residual current exceeds
Current val-
ue Res
setting.
2 out of 4
CB is in closed position and either of the fol-
lowing is true:
• Any phase current exceeds
Current value
setting and the residual current exceeds
Current value Res
setting.
• Two or three phase currents exceed
Cur-
rent value
setting.
Both(OR)
1 out of 3
Either of the following is true:
• CB is in closed position.
• Any phase current exceeds
Current value
setting.
1 out of 4
One of the following is true:
• CB is in closed position.
• Any phase current exceeds
Current value
setting.
• The residual current exceeds
Current val-
ue Res
setting.
2 out of 4
One of the following is true:
• CB is in closed position.
• Any phase current exceeds
Current value
setting and the residual current exceeds
Current value Res
setting.
• Two or three phase currents exceed
Cur-
rent value
setting.
Once activated,
TRBU
remains active until the set
Trip pulse time or until the reasons
for activation are reset.
TRRET
is also reset if
BLOCK
is activated.
In most applications, "1 out of 3" is sufficient.
Protection related functions
1MRS759142 F
1170
REX640
Technical Manual