User Guide SL7000 IEC7
52
Auxiliary Power Supply (APS)
Alarm is managed only if the APS parameter indicates that an auxiliary power supply is connected.
Appearance: The non fatal alarm will be generated when the APS voltage decreases strictly under the lower
dynamic threshold
Disappearance: The non fatal alarm will disappear when the APS voltage increases strictly above the upper
dynamic threshold.
Power failure
The meter detects a power failure when all three distribution-network phase voltages are lost.
The meter can be configured with a long power failure duration threshold value of between 0 and 255 seconds.
Any power failure durations:
•
below this preset value are short power failure occurrences
•
above this preset value are long power failure occurrences
The meter records the following power failure event parameters:
•
number of short power failures (incremental)
•
number of long power failures (incremental)
•
cumulated duration of long power failures
•
duration of the longest power failure (with start time stamp)
•
duration of the shortest power failure (with start time stamp)
•
the last 10 long power failures (with start time stamp and duration)
Frequency
The meter calculates the instantaneous frequency of the distribution-network voltage waveform using a zero
crossing technique that ensures an accurate result even if one or two incoming phases are lost.
The maximum and minimum frequency values within a billing period (page 47) are recorded by the meter.
