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 remains
active for the time set with the
Trip pulse time setting or until the values of
all the phase currents or residual currents drop below the
Current value and
Current value Res setting respectively, whichever takes longer.
- If
CB failure trip mode is set to "2 out of 4", the failure detection requires
that a phase current and a residual current both exceed the
Current value and
Current value Res setting respectively or two phase currents exceeding the
Current value. 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, whichever takes longer.
In most applications, "1 out of 3" is sufficient.
• If the
CB failure mode is set to "Breaker status", the
TRBU
output is activated
if the circuit breaker is in the closed position. Once activated, the
TRBU
output
remains 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 the
CB failure mode setting is set to "Both",
TRBU
is activated when the
"Breaker status" or "Current" mode conditions are satisfied.
The activation of the
BLOCK
input deactivates the
TRBU
output.
1MRS757644 H
Protection related functions
620 series
Technical Manual
811
