ABB RELION REX640, Техническое руководство, Страница: 1861 / 1960

Figure 984: Drop-off period is shorter than the set Reset delay time
When the drop-off period is shorter than the set Reset delay time, as described
in Figure 984 , 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
START
output and the operate timer starts elapsing. The Reset (drop-off)
timer starts when the timer input falls, that is, the fault disappears. Another fault
situation occurs before the reset (drop-off) timer has elapsed. This causes the
activation of the
OPERATE
output, since the operate timer already has elapsed.
1MRS759142 F General function block features
REX640
Technical Manual
1861