P54x/EN OP/La4 Operation
(OP) 5-180
MiCOM P543, P544, P545 & P546
OP
5.5.1 Circuit breaker control using hotkeys (P544/P546)
The hotkeys allow direct access to the manual trip and close commands without the need to
use the SYSTEM DATA column of the menu. Red or green color coding can be applied
when used in circuit breaker control applications.
IF <<TRIP>> or <<CLOSE>> is selected the user is prompted to confirm the execution of the
relevant command. If a “trip” is executed, a screen displaying the circuit breaker status will
be displayed once the command has been completed. If a “close” is executed a screen with
a timing bar will appear while the command is being executed. This screen has the option to
cancel or restart the close procedure. The timer used is taken from the manual close delay
timer setting in the CB Control menu. If the command has been executed, a screen
confirming the present status of the circuit breaker will be displayed. The user is then
prompted to select the next appropriate command or to exit - this will return to the default
relay screen.
If no keys are pressed for a period of 25 seconds whilst the P544/P546 is waiting for the
command confirmation, the P544/P546 will revert to showing the circuit breaker status. If no
key presses are made for a period of 25 seconds whilst the P544/P546 is displaying the
circuit breaker status screen, the P544/P546 will revert to the default relay screen. Figure
107 sho
ws the hotkey menu associated with circuit breaker control functionality.
To avoid accidental operation of the trip and close functionality, the hotkey circuit breaker
control commands are disabled for 10 seconds after exiting the hotkey menu.
5.5.2 Circuit breaker control using function keys (P544/P546)
The fun
ction keys allow direct control of the circuit breaker if programmed to do this in the
PSL. Local tripping and closing must be set in the CB Control menu CB control by cell to
one of the via “opto” settings to enable this functionality. All circuit breaker manual control
settings and conditions will apply for manual tripping and closing via function keys.
Figure 108 shows that the default logi
c can be programmed to activate this feature for CB1:
Function key 2 and function key 3 are both enabled and set to ‘Normal’ Mode and the
associated DDB signals (1097) and (1098) will be active high ‘1’ on a key press.
The following DDB signals must be mapped to the relevant function key:
Init Trip CB1 (DDB 439) - Initiate manual circuit breaker CB1 trip
Init Close CB1 (DDB 440) - Initiate manual circuit breaker CB1 close
The programmable function key LED’s have been mapped such that the LED’s will indicate
yellow whilst the keys are activated.
The diagram shows the control of CB1 only for simplicity. CB2 can be controlled in a similar
way and the relevant DDB signals are (441) Init Trip CB2, and (442) Init Close CB2.
5.6 Single and three phase auto-reclosing (P544/P546)
The a
uto-reclose scheme in the P544/P546 provides single phase or three phase auto-
reclosing of a feeder terminal switched by one or two circuit breakers.
With the P544/P546, the user can select to initiate auto-reclosure following any Zone 1, or
distance-aided scheme trips which occur. In addition, the user can selectively decide to
auto-reclose for trips from time-delayed distance zones, overcurrent and earth (ground)
elements, and DEF aided schemes.
In a two circuit breaker scheme, the circuit breakers are normally arranged to reclose
sequentially with one designated leader circuit breaker reclosing after a set dead time
followed, if the leader circuit breaker remains closed, by the second circuit breaker after a
further delay, the follower time. In the operational description, the two circuit breakers are
designated as CB1 and CB2. The scheme can be configured by menu settings, by control
commands, or by opto inputs to operate in any of the following modes for the first shot (first
auto-reclose attempt):
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