ABB RELION 630 Series Technical Manual page 327

1MRS757256 F
PML630/Compact Load-Shedding Solution
Technical Manual
Timer input
OC_STR
OC_OPR
Reset timer
Operate timer
GUID-4A7EFE31-446D-43EF-BDEE-E925F2F1C284 V1 EN
Figure 167: Drop-off period is longer than the set Reset delay time
When the drop-off period is longer than the set Reset delay time, as described in
167, the input signal for the definite timer (here: timer input) is active, provided that
the current is above the set Start value. The input signal is inactive when the current
is below the set Start value and the set hysteresis region. The timer input rises when a
fault current is detected. The definite timer activates the OC_STR output and the
operate timer starts elapsing. The reset (drop-off) timer starts when the timer input
falls, that is, the fault disappears. When the reset (drop-off) timer elapses, the operate
timer is reset. Since this happens before another start occurs, the OC_OPR output is not
activated.
General function block features
Reset delay time
Operate delay time
Section 9
Figure
321