ABB REF 610 Technical Reference Manual page 40

REF 610 REF 610
40
Feeder Protection Relay
Technical Reference Manual
Circuit-breaker closing
When the set dead time elapses, the AR function will issue a reclosing command to
the circuit breaker (Close CB Command). Reclosing can be inhibited via a digital
input (CB Close inhibit). External inhibition of reclosing by the digital input
signal is selected in SGB.
When reclosing is inhibited, or the circuit breaker does not close before expiration
of the set CB closing time, the circuit breaker will remain open and the AR function
will generate a CB Reclosing Failed signal.
Reclosing is inhibited and the CB Reclosing Failed signal generated also if an
AR initiation signal is active, i.e. the fault has not been cleared, when reclosing
begins.
The duration of the reclosing command is settable (CB closing time). However,
reclosing of the circuit breaker will end immediately after the AR function has
received information that the circuit breaker has been closed, or if a protection trips
the circuit breaker again.
Blocking of protection elements
In several applications, such as fuse-saving (refer to 6.1.1. Fast tripping and
initiation of shot 1 using two protection stages), the aim is at fast tripping and
initiation of shot 1 and delayed tripping and initiation of shot 2 and 3. Consequently,
if two protection s are used, one fast and the other one delayed, the fast stage should
be set to be blocked by the AR function during shot 2 and 3.
The protection stages can be set to be blocked at shot 1 and/or shot 2 and 3. The
selection is made in SG2 (see Table 5.1.4.10.-11).
Definite trip alarm
The AR function generates a definite trip alarm signal after an unsuccessful auto-
reclose sequence, i.e. when no more auto-reclose shots are allowed but the network
fault has not be cleared, the circuit breaker is open and there is no ongoing shot. The
definite trip alarm signal is also be generated in case a protection trips the circuit
breaker while the AR function is inhibited.
The definite trip alarm signal is active for 1 second.
The definite trip alarm signal will not be generated if the AR function
has been set out of operation.
1MRS755310