Displaying Odd & Even Harmonics or Odd Harmonics Only
The Model 725 may be set up to display odd & even harmonics or only
odd harmonics. Pressing HARM while turning the Model 725 ON will
select either odd + even or odd harmonic orders only. When only odd
harmonics are set up, ODD is displayed on the LCD to the left of the har-
monic order Hxx.
The Model 725 will display the amplitude or frequency of each individ-
ual harmonic as well as the percentage relative to the fundamental signal
or to the RMS.
Measuring the K Factor (see p. 39)
While measuring Harmonics, and only in A AC, pressing the yellow Shift
button gives access to the K Factor. The push button sequence is:
Harmonic measurement → K factor → Harmonic measurement
Total Harmonic Distortion (%THD)
%THD is the Total Harmonic Distortion, referenced to the fundamental
(50/60 Hz) signal. The THD is expressed as a percentage and may be
greater than the fundamental. A reading greater than 100% is possible.
The %THD is also referred to as the Harmonic Factor or %THD-F.
%THD Application Example:
Calculating the amount of total harmonic current: It is possible to calculate
total harmonic current from a %THD reading when fundamental (60
Hz) current or voltage is measured (H01).
Example
The Model 725 measures fundamental current (H01) of 150 A and a
THD of 130%. This means that the harmonic content is 130% of the
fundamental (60 Hz).
150 A x 1.3 = 195 A
Harmonic current = 195 A
30
Clamp-On Harmonic Probe Model
To Next Page
Loading...
