ABB RER620, Technical Manual

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Section 5
1MAC309294-MB F
Control functions
328 RER620
Technical Manual
Figure 169: A simplified block diagram of the synch-check function in the continuous
mode operation
Command mode
If Control mode is set to “Command”, the purpose of the synch-check functionality in the
command mode is to find the instant when the voltages on both sides of the circuit breaker
are in synchronism. The conditions for synchronism are met when the voltages on both
sides of the circuit breaker have the same frequency and are in phase with a magnitude that
makes the concerned busbars or lines can be regarded as live.
In the command control mode operation, an external command signal
CL_COMMAND
,
besides the normal closing conditions, is needed for delivering the closing signal. In the
command control mode operation, the synch-check function itself closes the breaker via
the
SYNC_OK
output when the conditions are fulfilled. In this case, the control function
block delivers the command signal to close the synch-check function for the releasing of
a closing signal pulse to the circuit breaker. If the closing conditions are fulfilled during a
permitted check time set with
Maximum Syn time , after the command signal is delivered
for closing, the synch-check function delivers a closing signal to the circuit breaker.
Figure 170: A simplified block diagram of the synch-check function in the command
mode operation
The closing signal is delivered only once for each activated external closing command
signal. The pulse length of the delivered closing is set with the
Close pulse setting.