Multi-Tech Systems 7500, 7600 manual Interharmonic Voltage

ION 7500 / ION 7600 User’s Guide Interharmonic Voltage

Interharmonic Voltage

Interharmonics are the entire band of frequencies between two successive integer multiples of the fundamental. All harmonic measurements are performed as defined in 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 interharmonic levels defined in the table below are exceeded and the supply voltage is within ±15% of nominal. Levels for interharmonic bands up to the 25th harmonic are defined in the table below.

Apply your own compliance evaluation criteria to the interharmonic statistics provided by the meter.

In the table below, order 2 specifies all frequencies between the fundamental and the 2nd harmonic; order 3 specifies all frequencies between the 2nd harmonic and the 3rd; etc.

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 and N1counts 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 and N1 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 a message in the Event log every time the N1 counter increases.

Power Quality: ION Meters and EN50160 Technical Note Page 319