•
Closed position signal of circuit breaker is going
This signal is derived form the circuit-breaker auxiliary contacts. In this way, opening the circuit-breaker
manually is detected.
Logic Input Signals for Stages
As soon as the start criterion has been fulfilled, the timers of the parameterized opening time and break time
are started. With the parameter CB opening time, the time when the circuit-breaker pole begins to open is
defined. With the parameter CB break time, the time of the pole being open including the arc extinction is
defined. The following figure shows the relationship between these circuit-breaker times.
[DwCBTime, 2, en_US]
Figure 10-32
Circuit-Breaker Times
In order to prevent an incorrect calculation in case of a circuit-breaker failure, the parameter Current
thresh. CB open is used to verify whether the current actually returns to 0 after 2 additional cycles. Funda-
mental components are used for comparing the threshold values. When the current criterion fulfills the
requirement of the phase-selective logic release, the calculation and evaluation of the respective methods are
initiated.
End Criterion for the Circuit-Breaker Wear Monitoring Function
After calculation and evaluation have been completed, the end criterion of the circuit-breaker maintenance is
fulfilled. The Circuit-breaker wear monitoring function is ready for a new initiation.
Application and Setting Notes
Parameter: CB opening time
•
Default setting value (_:2311:101) CB opening time = 0.065 s
You use the CB opening time parameter to define the time span from energizing the shunt release of the
circuit breaker until the start of opening of switching poles.
You can find the information on the setting value in the technical data of the used circuit breaker. Also refer to
Figure 10-32.
10.12.3.2
Measured Values, Energy Values, and Supervision of the Primary System
10.12 Circuit-Breaker Wear Monitoring
SIPROTEC 5, Overcurrent Protection, Manual 1355
C53000-G5040-C017-8, Edition 07.2017
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