ABB RELION REX640 Technical Manual page 1398

Section 9
Control functions
1392
GUID-05585046-268A-4EE1-951C-9F9429070A6F V1 EN
Figure 744: 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 Synchro check function. If the
external command signal CL_COMMAND is kept active longer than necessary, the
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.
Maximum Syn time
GUID-3A16B732-F9FC-46CE-A827-3219CA85A828 V1 EN
Figure 745: Determination of the alarm limit for a still-active command signal
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
Maximum Syn time
Close pulse
5s
1MRS759142 C
REX640
Technical Manual