Hitachi Relion 650 Series Technical Manual page 318

Section 12
Monitoring
Mechanical health alarm
After completion of every switching operation, ACBMSCBR checks the final status of the connected
auxiliary contacts against the switching operation type (Close or Open). The result is given at the
MECHHOLX output.
health.
Table 284: Circuit breaker mechanical health derived from status of auxiliary contacts after operation
Operation type
Close
Close
Close
Close
Open
Open
Open
Open
X
X
Contradicting CB positions alarm
ACBMSCBR detects a contradictory position whenever the circuit breaker appears electrically
conducting although it is mechanically open. This is evaluated from the selected electrical feedback
signal and available auxiliary contacts, as per
CBSTSLX = "El close mec open" for more than 100 ms, the CNTPOSOLX output is activated; it
remains active as long as this contradicting condition persists.
Ablation alarm and warning
ACBMSCBR compares the cumulated contact ablation (ABLSUMLX, see
different thresholds to raise alarms and warnings.
An ablation-based alarm is raised by activating the ALABLLX output wheneverAblationAlm is
enabled and
ABLSUMLX > AblationAlarmLevel
Similarly, an ablation-based warning is raised by activating the WRABLLX output whenever
AblationAlm is enabled and
ABLSUMLX > AblationWarnLevel
The alarm and warning outputs remain high till the cumulated ablation is manually reset or the limits
are increased above the cumulated ablation value.
Out-of-limit operation count alarm
A CB switching operation is declared out-of-limit if one of the monitored values exceeds an alarm
threshold. This information is taken from the ALMS1T5A, ALMS6T10A, and ALMS6T10B
coordination inputs.
The coordination inputs comprise 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.
Table 285
phase.
312
Table 284 presents the logic table for assessing the circuit breaker's mechanical
AuxPosAvailable
NO and NC/ NC only
NO and NC/ NO only
NO and NC
NO and NC
NO and NC/ NO only
NO and NC/ NC only
NO and NC
NO and NC
X
None
lists the bit combinations that are interpreted as out-of-limit operation for the respective
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MechMonitor INPNOLX INPNCLX
Enable 0
Enable 1
Enable 0
Enable 1
Enable 1
Enable 0
Enable 0
Enable 1
Disable X
X X
Table 271. If ContradPosAlm is set to "Enable" and
1MRK 511 557-UEN Rev. A
GUID-48400CB5-263B-4AC3-B246-6EC052A728EA v2
MECHHO
LX
1 Alarm
0 OK
0 Warning
1 Alarm
0 Alarm
1 OK
0 Warning
1 Alarm
X OK
X OK
GUID-A1461B49-834D-4385-A80F-18A0BAB63F9F v2
GUID-0E3DC9D8-AF8D-419D-B1B8-A8616A4B541F v3
Section 12.18.7.14) with
GUID-84FF5252-A045-4520-824B-681F1808B5F5 v2
Technical Manual