Alstom MiCOM P546 - 5.6.2.4 Reset lockout (P544;P546); 5.6.2.5 Pole discrepancy (P544;P546); 5.6.2.6 External trip (P544;P546)

Operation P54x/EN OP/La4
MiCOM P543, P544, P545 & P546 (OP) 5-183
OP
5.6.2.4 Reset lockout (P544/P546)
The Reset Lockout input can be used to reset the auto-reclose function following lockout
and reset any auto-reclose alarms, provided that the signals which initiated the lockout have
been removed.
The following DDB signals are available for mapping in PSL from opto inputs or
communications inputs :
DDB (446) Rst CB1 Lockout: Reset Lockout Opto Input to reset CB1 Lockout state
DDB (1422) Rst CB2 Lockout: Reset Lockout Opto Input to reset CB2 Lockout state
5.6.2.5 Pole discrepancy (P544/P546)
Circuit
breakers with independent mechanisms for each pole normally incorporate a ‘phases
not together’ or ‘pole discrepancy’ protection device which automatically trips all three
phases if they are not all in the same position i.e. all open or all closed.
During single pole auto-reclosing a pole discrepancy condition is deliberately introduced and
the pole discrepancy device must not operate for this condition. This may be achieved by
using a delayed action pole discrepancy device with a delay longer than the single pole auto-
reclose dead time, SP AR Dead Time.
Alternatively, a signal can be given from the relay during the single pole auto-reclose dead
time, AR 1 Pole In Progress, to inhibit the external pole discrepancy device.
In the relay, the Pole Discrepancy input is activated by a signal from an external device
indicating that all three poles of the CB are not in the same position. The Pole Discrepancy
inputs, DDB (451) & DDB (1606) forces a 3 pole trip on CB1 & CB2 respectively through
PSL mapping.
The logic diagram for the pole discrepancy is shown in AR Figure 62 (logic diagram
sup
plement).
5.6.2.6 External trip (P544/P546)
The Ex
ternal Trip 3Ph input and the External Trip A, External Trip B and External Trip C
inputs can be used to initiate three or single phase auto-reclose.
Note: These signals are not used to trip the circuit breaker but do initiate
auto-reclose. To trip the circuit breaker directly they could be
assigned to the trip contacts of the relay in the PSL.
The following DDB signals are available for mapping in PSL from opto inputs to initiate auto-
reclosing.
DDB (535): CB1 Ext Trip A
DDB (536): CB1 Ext Trip B
DDB (537): CB1 Ext Trip C
DDB (534): CB1 Ext Trip 3Ph
DDB (539): CB2 Ext Trip A
DDB (540): CB2 Ext Trip B
DDB (541): CB2 Ext Trip C
DDB (538): CB2 Ext Trip 3Ph