Supply voltage variations

Each measurement is the 10-minute RMS (root mean square) voltage for each phase.

Observation period of one week with fixed steps of 10 minutes.
N = the number of valid 10-minute intervals monitored by your meter.
N₁ = number of intervals in which the supply voltage exceeds ± 10% of nominal.
N₂ = number of intervals in which the supply voltage exceeds +10%, -15% of nominal.
N_invalid = the number of observed intervals or partial intervals that are not included in EN50160:2010 compliance calculations.

Supply voltage complies with the standard if N₁/N ≤ 5% during the observation period and N₂ = 0.

EN50160 data (current observation period): the meter generates the N, N₁ and N₂ counts described. These counters are reset at the beginning of the next observation period.

EN50160 data (previous observation period): the meter stores the N, N₁ and N₂ counter values at the end of each observation period 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 the N₁ and N₂ counters increases.