is constant and does not depend on the voltage fluctuations during the drop-off
period.
There are three ways to reset the timer: the timer is reset instantaneously, the timer
value is frozen during the reset time, or the timer value is linearly decreased during
the reset time. See figure
81 and figure 82.
TRIP
U1>
TRIP
t
Time
Time
Integrator
t
Frozen Timer
Instantaneous
Voltage
Voltage
Time
HystAbs1
START
START
tIReset1
Measured
tIReset1
Linearly decreased
IEC09000055-2-en.vsd
IEC09000055 V2 EN-US
Figure 81: Voltage profile not causing a reset of the START signal for step 1, and inverse time delay
1MRK 505 384-UEN A Section 7
Voltage protection
Breaker protection REQ650 2.2 IEC 193
Technical manual
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