ABB RELION 620 Series Technical Manual page 765

1MAC504801-IB E
620 series ANSI
Technical Manual
Closing is permitted during Maximum Syn time, starting from the moment the external
command signal CL_COMMAND is activated. The CL_COMMAND input must be kept
active for the whole time that the closing conditions are waited to be fulfilled. Otherwise,
the procedure is cancelled. If the closing-command conditions are fulfilled during
Maximum Syn time, a closing pulse is delivered to the circuit breaker. If the closing
conditions are not fulfilled during the checking time, the alarm CL_FAIL_AL is activated
as an indication of a failed closing attempt. The closing pulse is not delivered if the closing
conditions become valid after Maximum Syn time has elapsed. The closing pulse is
delivered only once for each activated external command signal, and a new closing-
command sequence cannot be started until the external command signal is reset and
reactivated. The SYNC_INPRO output is active when the closing-command sequence is
in progress and it is reset when the CL_COMMAND input is reset or Maximum Syn time has
elapsed.
Bypass mode
25 can be set to the bypass mode by setting the parameters Synchro check mode and
Energizing check mode to "Off" or alternatively by activating the BYPASS input.
In the bypass mode, the closing conditions are always considered to be fulfilled by 25.
Otherwise, the operation is similar to the normal mode.
Voltage angle difference adjustment
In application where the power transformer is located between the voltage measurement
and the vector group connection gives phase difference to the voltages between the high-
and low-voltage sides, the angle adjustment can be used to meet synchronism.
Section 9
Control functions
759