Hitachi Relion 650 Series Technical Manual page 297

1MRK 511 557-UEN Rev. A
Reference
voltage
Current
COPCMD
LX
IEC19000761 V2 EN-US
Figure 131: Detection of current interruption instant
IEC19000762 V2 EN-US
Figure 132: Detection of precise current interruption instant
The function initially detects the breaker state change from the RMS value of the electrical feedback
signal: The breaker is assumed open as soon as the RMS value drops below the absolute
OpenCThreshold value. From the point where the feedback signal was last seen above the
threshold, the function forward-tracks the samples until the absolute value is less than or equal to
OpenFThreshold. This sample with corresponding timestamp is considered the interruption instant.
When using voltage feedback with capacitor or uncompensated line/cable load, the interruption
instant is detected as shown in
Reference
voltage
Load
Voltage
COPCMDLX
IEC19000768 V2 EN-US
Figure 133: Detection of load voltage interruption instant for capacitive load
Technical Manual
Interruption instant
Figure 133 and Figure
Interruption Instant
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OpenCThreshold
OpenFThreshold
Interruption
Instant
OpenCThreshold
OpenFThreshold
134.
Section 12
Monitoring
IEC19000768-1-en.vsdx
291