Hitachi Relion 650 Series Technical Manual page 317

1MRK 511 557-UEN Rev. A
Mechanical operating time alarm
The estimated mechanical operating time AMCOTMLX can be compared against alarm thresholds
outside ACBMSCBR (see MONALM function), separately for closing time and opening time. The
comparison results are fed back to ACBMSCBR through the coordination input ALMS1T5A. If
enabled by the OpTmAlm setting, operating times outside the limits will raise an alarm on the
ALOPTMLX output. This output is activated for only one task cycle.
ALMS1T5A comprises alarm status for all three phases. Depending on the system phase to which an
ACBMSCBR instance is assigned, it extracts the relevant information for that phase only.
lists the bit combinations that indicate a mechanical operating time alarm for the respective phase
and the resulting output values.
Table 283: Mechanical operating time alarm
Phase ALMS1T5A
Instan
Bit0 Bit1 Bit2
ce
L1 1 0 X
X X X
L2 X X 1
X X X
L3 X X X
X X X
X X X X
Unstable breaker alarm
If both MechMonitor and UnstOpChrAlm are set to "Enable", ACBMSCBR checks for consistency of
the actual mechanical operating times. Specifically, it evaluates the difference between the last three
operations of the same type (Close or Open). If the actual mechanical operating time of the second
operation is 10% deviated from the actual mechanical operating time of the first operation and the
actual mechanical operating time of the third operation is 10% deviated from the actual mechanical
operating time of the second operation, the breaker is declared unstable. This is indicated by
activating the UNSTOPOLX output. The output remains high till the alarm is manually cleared.
Re-ignition/re-strike detected alarm
If RestrReigAlm is set to "Enable" and a re-ignition or re-strike has been detected (see
12.18.7.11.3, the RSTRDETLX output is activated for one task cycle.
Overcurrent detection Alarm
If "Current" is selected for either FeedbackSigC or FeedbackSigO, ACBMSCBR continuously
compares the primary current RMS to the overcurrent threshold, which is calculated as
OvercurrentThresh · IBase / 100. If the current exceeds the threshold, the OVCURLX output is
activated; it remains active as long as till the current RMS is higher than the overcurrent threshold.
Maximum re-strike/re-ignition correction alarm
As explained in
limit is reached. Upon encountering the maximum correction limit with an enabled MaxReStrCorrAlm
setting, the ALMAXRCLX output is activated. This output remains high till the re-strike/re-ignition
correction is manually cleared.
Technical Manual
Bit3 Bit4 Bit5 Bit6
X X X X
X X X 0
0 X X X
X X X X
X 1 0 X
X X X X
X X X X
Section 12.18.7.13.2, ACBMSCBR adapts to re-strikes/re-ignitions till the correction
© 2021 Hitachi Energy. All rights reserved.
Bit7 Bit8 Bit9 Bit10
X X X X
1 X X X
X X X X
X 0 1 X
X X X X
X X X 0
X X X X
Section 12
Monitoring
GUID-AE77D9AD-AAC1-4AFB-BE35-8771A5CD6C21 v2
Table 283
Bit11 Bit12- opTm ALOP
31 Alm TMLX
X X Enabl 1
e
X X Enabl 1
e
X X Enabl 1
e
X X Enabl 1
e
X X Enabl 1
e
1 X Enabl 1
e
X X Disab 0
le
GUID-B70F1379-1CC4-4E6B-B526-053E58436803 v1
GUID-4964A9F2-5F82-4047-A785-86BD45558096 v2
Section
GUID-258ED089-6358-4ED2-A99F-0EFCFE11982C v2
GUID-86554F0C-08E2-4F13-A2F4-FC8BA0AF4761 v2
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