Hitachi Relion 650 Series Technical Manual page 296

Section 12
Monitoring
IEC19000915 V1 EN-US
Figure 130: Electrical monitoring of CB opening, shown for current feedback
The monitored quantities are evaluated from the electrical feedback selected by FeedbackSigO.
Based on the detected instant of interruption, the electrical interruption time is evaluated as the time
difference between the instant of controlled trip command (COPCMDLX) and the interruption instant
as shown in
estimated instant of breaker contact separation and the interruption instant.
The interruption instant is determined based on the settings OpenCThreshold and OpenFThreshold.
Both settings are defined in percent of global base values. So, based on the configured
FeedbackSigO (Current or load voltage), the global base value of the current or voltage is used to
convert OpenCThreshold and OpenFThreshold into absolute values, same as for closing (described
above).
For detecting the interruption instant, two different algorithms are applied depending on selected
feedback signal and load type.
When using current feedback with capacitor or reactor or transmission line load, or voltage feedback
with reactor or transformer load, the interruption instant is detected as shown in
Figure 132, using the absolute values of OpenCThreshold and OpenFThreshold.
290
Trip
Command
Electrical
interruption time
Figure 130. Similarly, the arcing time is evaluated as the time difference between
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Time(t)
Arcing
time
1EC19000915-1-en.vsdx
1MRK 511 557-UEN Rev. A
Figure 131 and
Technical Manual