Flagging concept
During a voltage dip, swell, or interruption, measurements
of other power quality parameters may produce unreliable results.
The flagging concept avoids counting a single event more than once in different parameters, for example, counting a single dip as both a dip and frequency variation. A flagged measurement indicates that the aggregated value might be unreliable.
Flagging is only triggered by supply voltage dips, swells and interruptions.
Flagging applies to Class A and Class S devices during the measurement of:
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Power frequency.
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Magnitude of the supply voltage.
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Flicker.
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Supply voltage unbalance.
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Voltage harmonics.
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Voltage interharmonics.
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Mains signalling.
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Underdeviation and overdeviation.
NOTE: 4-30 flagging is disabled while the meter is powered down. If
the meter is powered down, all flagged measurements and corresponding
aggregated values for the active 4-30 reporting interval will be lost.