ABB RER620 Technical Manual page 335

1MAC309294-MB F
RER620
Technical Manual
Figure 171: Determination of the pulse length of the closing signal
In the command control mode operation, there are alarms for a failed closing attempt
(CL_FAIL_AL) and for a command signal that remains active too long
(CMD_FAIL_AL).
If the conditions for closing are not fulfilled within set time of Maximum Syn time, a failed
closing attempt alarm is given. The CL_FAIL_AL alarm output signal is pulse shaped and
the pulse length is 500 ms. If the external command signal is removed too early, that is,
before conditions are fulfilled and close pulse is given, the alarm timer is reset.
Figure 172: Determination of the checking time for closing
The control module receives information about the circuit breaker status and thus is able
to adjust the command signal to be delivered to the synch-check function. If the external
command signal CL_COMMAND is kept active longer than necessary, CMD_FAIL_AL
alarm output is activated. The alarm indicates that the control module has not removed the
external command signal after the closing operation. To avoid unnecessary alarms, the
duration of the command signal should be set in such a way that the maximum length of
the signal is always below Maximum Syn time + 5s.
Section 5
Control functions
329