P54x/EN OP/La4 Operation
(OP) 5-192
MiCOM P543, P544, P545 & P546
OP
Where L refers to the leader circuit breaker, F refers to the follower circuit breaker, 1P
implies single phase, 3P implies three phase, and 1/3P implies single or three phase, so a
setting of L1/3P F3P would mean that the leader circuit breaker could perform single or three
phase auto-reclose, whilst the follower would perform three phase auto-reclose only.
If the auto-reclose mode selection is by Opto then the reclose mode for the active leader is
determined by the status of two DDB inputs: Lead AR 1P (1497) to enable single phase
auto-reclose, and “Lead AR 3P” (1498) to enable three phase auto-reclose. The reclose
mode for the active follower is determined by the status of two DDB inputs: Follower AR 1P
(1409) to enable single phase auto-reclose, and Follower AR 3P (1410) to enable three
phase auto-reclose.
Where the selected follower auto-reclose mode supports single phase tripping, the follower
can perform single phase auto-reclose only if the leader circuit breaker has performed single
phase auto-reclose. If the leader has tripped and reclosed three phase, the follower is also
forced to trip three phase. The follower will reclose three phase provided three phase auto-
reclose is permitted for the follower circuit breaker. If the follower circuit breaker trips three
phase and three phase auto-reclose is not permitted for the follower, then the follower circuit
breaker locks out without reclosing.
5.6.6.5 Force three phase trip (P5
44/P546)
The force three phase trip logic is shown in AR Figure 10 (logic diagram supplement).
Followi
ng single phase tripping, whilst the auto-reclose cycle is in progress, and upon
resetting of the protection elements, an output signal DDB associated with the tripped circuit
breaker is asserted high.
In the case of CB1, this is DDB: AR Force CB1 3P (858).
In the case of CB2, this is DDB: AR Force CB2 3P (1485).
These signals are applied to any associated protection trip conversion logic to force all
protection trips to be converted to three phase trips for the associated circuit breaker, for any
subsequent faults that occur whilst the auto-reclose cycle remains in progress.
5.6.6.6 Auto-reclose Initiation (P54
4/P546)
The auto-reclose initiation logic is shown in AR Figure 11, Figure 12, Figure 13 and
Figure 14 (logic diagram supplement).
Auto-re
close cycles can be initiated by :-
Protection functions hosted by the P544/P546
External protection equipment
Trip test
Auto-reclose initiation will start an auto-reclose for any circuit breaker that is in service and
enabled for auto-reclose: CB1 auto-reclose will start if CB1 is in service and enabled for
auto-reclose; CB2 auto-reclose will start if CB2 is in service and enabled for auto-reclose.
When an auto-reclose cycle is started, the relevant circuit breaker auto-reclose in progress
CB1 ARIP and/or CB2 ARIP signal is set, and remains set until the end of the cycle for the
associated circuit breaker. The end of the cycle is signified by successful reclosure, or by
lockout.
5.6.6.6.1 Auto-reclose initiation by host relay protection function (P544/P546)
Many prote
ction functions in the P544/P546 (for example differential trips, Zone 1 trips,
distance-aided scheme trips, time-delayed distance zones, overcurrent and earth (ground)
elements, DEF and directional aided schemes.) can be programmed to initiate or block auto-
reclose by selecting the Initiate AR, or Block AR options in the settings which are available
under the AUTORECLOSE settings column of the menu. Operation of a protection function
selected for auto-reclose will initiate auto-reclose. Operation of a protection function
selected to block auto-reclose will block and force a lockout.
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