ABB RED615 Technical Manual page 690

Section 9
Control functions
684
Command mode
If Control mode is set to "Command", the purpose of the Synchro 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 such
that they can be regarded as live.
In the command 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 Synchro 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 Synchro 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, the Synchro check function delivers a closing signal to the circuit breaker
after the command signal is delivered for closing.
Closing
request
CBXCBR
GUID-820585ED-8AED-45B1-8FC2-2CEE7727A65C V2 EN
Figure 366: A simplified block diagram of SECRSYN 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.
Closing
command
SECRSYN
1YHT530004D05 D
I
615 series
Technical Manual