Supply voltage dips

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

Conventionally, for low voltage networks, the dip start threshold is equal to 90% of the nominal voltage and hysteresis is typically 2%. The observation period is one week.

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

Voltage dips classification

Residual voltage u (%)	0.01 ≤ t ≤ 0.2¹	0.2 < t ≤ 0.5¹	0.5 < t ≤1¹	1 < t ≤ 5¹	5 < t ≤ 60 ¹
90 > u ≥ 80	A1	A2	A3	A4	A5
80 > u ≥ 70	B1	B2	B3	B4	B5
70 > u ≥ 40	C1	C2	C3	C4	C5
40 > u ≥ 5	D1	D2	D3	D4	D5
5 > u	X1	X2	X3	X4	X5
¹ Duration = 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 tables 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 tables 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 tables increases.