Multi-Tech Systems 7600, 7500 manual Harmonic Voltage

Harmonic Voltage ION 7500 / ION 7600 User’s Guide

Harmonic Voltage

All harmonic measurements are performed as defined by IEC 61000-4-7.

Observation period of one week with fixed steps of 10 minutes.

N = number of 10-minute intervals in which the supply voltage is within ±15% of nominal.

N1 = number of intervals in which one or more of the individual harmonic levels defined in the table below are exceeded and the supply voltage is within ±15% of nominal. Levels for individual harmonics (for each phase) up to the 25th are defined in the table below.

N2 = number of intervals in which the THD value for one or more of the voltage phases exceeds 8% and the supply voltage is within ±15% of nominal. The THD calculation will include all harmonics up to the 40thd).

Harmonic voltage complies with the standard if N1/N <= 5% and N2/N <= 5% during the observation period (1 week by default).

Odd Harmonics

Not Multiples of 3				Multiples of 3
Order	Threshold	Order	Threshold	Order	Threshold
5	6%	17	2%	3	5%
7	5%	19	1.5%	9	1.5%
11	3.5%	23	1.5%	15	0.5%
13	3%	25	1.5%	21	0.5%

Even Harmonics

Order Threshold

2 2%

41%

6…24 0.5%

EN 50160 data (current observation period): The meter generates the N, N1 and N2 counts described above for each phase. These counters are reset at the beginning of the next observation period.

EN 50160 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 9 registers are also stored in a data recorder for each observation period.

Events: The meter creates a message in the Event log every time the N1 and N2 counters increase.

Parameter data: The meter can be enabled to record the 10-minute mean, minimum and maximum values of THD, TO(odd)HD and TE(even)HD for each voltage phase into a data recorder every 10 minutes.

Page 316 Power Quality: ION Meters and EN50160 Technical Note