ABB RELION 670 SERIES Applications Manual page 680

Section 15
Control
674
when the WAIT input resets. The mimimum settable time for tSlaveDeadTime is 0.1sec
because both master and slave should not send the breaker closing command at the same
time. The slave should take the duration of the breaker closing time of the master into
consideration before sending the breaker closing command. A setting tWaitForMaster
sets a maximum wait time for the WAIT input to reset. If the wait time expires, the
reclosing cycle of the slave is inhibited. If auto reclosing of the first breaker is
unsuccessful, the UNSUCCL output connected to the INHIBIT input of the slave unit
interrupts the auto reclosing sequence of the latter.
The signals can be cross-connected to allow simple changing of the
priority by just setting the High and the Low priorities without changing
the configuration. The input 52a for each circuit breaker is important in
multi-breaker arrangements to ensure that the circuit breaker was closed
at the beginning of the cycle. If the High priority circuit breaker is not
closed the High priority moves to the low priority circuit breaker.
1MRK 506 369-UUS -
Line distance protection REL670 2.2 ANSI
Application manual