Supply voltage swells

All voltage supply swell measurements are performed as defined by IEC 61000-4-30.

Conventionally, for low voltage networks, the duration of the swell corresponds to the period during which the RMS value remains more than 110% of the nominal voltage. The magnitude of the swell is defined as the ratio (expressed as a percentage) between the maximum RMS voltage during the swell and the nominal voltage. The observation period is 1 week.

Multiple phase events are combined into single, equivalent events using polyphase aggregation. These equivalent events are used to classify swells.

Swell counters classification

Residual voltage u (%)	0.01 ≤ t ≤ 0.5¹	0.5 < t ≤ 5¹	5 < t ≤ 60¹	t > 60¹
u ≥ 120	S1	S2	S3	S4
120 > u > 110	T1	T2	T3	T4
¹Duration = t (in seconds).

NOTE: The figures to be put in the cells refer to the number of equivalent events.

EN50160 data (current observation period): the meter maintains the counters listed in the previous table for each phase. These counters are reset at the beginning of the next observation period.

EN50160 data (previous observation period): the meter stores the counters listed in the previous table for each phase on a weekly basis before these counters are reset. These registers are also stored in a data recorder for each observation period.

Events: the meter creates an entry in its onboard event log every time one of the counters listed in the previous table increases.

Counters for the current observation period are located in Bin modules, and are also recorded weekly by the EN50160 Swell data recorders.

Register labels
V-Swell S1	V-Swell S2	V-Swell S3	V-Swell S4
V-Swell T1	V-Swell T2	V-Swell T3	V-Swell T4

The following counters are from the previous observation period (PO). These values are all located in Store modules containing the prefix PO.

Register labels
PO V-Swell S1	PO V-Swell S2	PO V-Swell S3	PO V-Swell S4
PO V-Swell T1	PO V-Swell T2	PO V-Swell T3	PO V-Swell T4

The minimum RMS voltage for each phase during the swell, the duration of the swell, and the timestamp for when the swell occurred are recorded in the Sag/Swell log data recorder.