Operation Principle - Hitachi Relion 650 Series Technical Manual

Section 12
Monitoring
Name
ALR8L3
ALR9L1
ALR9L2
ALR9L3
12.17.7

Operation principle

The Multilevel threshold alarm generation MONALM function triggers an alarm when an analog
quantity is not in a normal range.
MONALM works on the principle of comparing the analog quantity against a set of thresholds in two
directions at two different levels on either side. Nine analog quantities, for example, control voltage,
temperature, drive pressure, spring pressure and so on can be monitored such that when they
exceed the threshold values, alarms are generated. The binary signals are the supervising levels of
an analog signal, whose status level (for example, gas pressure, spring charge status and so on)
indicates when the analog signal falls below the threshold.
Use the setting InpxSensorMode to select the number of signals to supervise in a channel: Select "1
Sensor Mode" if a single sensor signal is connected to the corresponding IxL1 input, else select "3
Sensor Mode" for three sensor signals (one per phase).
Up to nine analog input signals can be supervised. For each signal, one or two supervision
thresholds can be configured in each direction, or supervision can be disabled altogether in any
direction.
The binary input level alarm can be configured to indicate Warning, Alarm and/or High Alarm.
• If the full level binary signal is high, no warning or alarm is generated, regardless of the status of
the other binary signals.
• If the full level binary signal is low and the medium level signal is high, Warning goes high.
• If only the low level signal is high, Alarm goes high.
• If all binary inputs are low, High Alarm goes high.
For analog quantities, exceeding the thresholds can trigger one of the four alarms. The output
ALRxLn can have different values according to the conditions defined below:
• 0 (normal range) indicates, the input signal is in normal range, that is, between low and high
warning limits, or the alarm input IxALn is high
• 1 (high warning) indicates, the signal has risen to or above InpxHiLimit
• 2 (low warning) indicates, the signal has dropped to or below InpxLoLimit
• 3 (high alarm) indicates, the signal has risen to or above InpxHiHiLimit
• 4 (low alarm) indicates, the signal has dropped to or below InpxLoLoLimit
where x indicates the analog input and n indicates the phase.
256
Type Values (Range)
INTEGER 0=Normal
1=High Warning
2=Low Warning
3=High Alarm
4=Low Alarm
INTEGER 0=Normal
1=High Warning
2=Low Warning
3=High Alarm
4=Low Alarm
INTEGER 0=Normal
1=High Warning
2=Low Warning
3=High Alarm
4=Low Alarm
INTEGER 0=Normal
1=High Warning
2=Low Warning
3=High Alarm
4=Low Alarm
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Unit Description
- Alarm range integer value for signal 8 L3
- Alarm range integer value for signal 9 L1
- Alarm range integer value for signal 9 L2
- Alarm range integer value for signal 9 L3
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Technical Manual