37

38

8

 Harmonic measurement function

      Press HARM key for circulation switchover of following harmonic measurement functions. 3 
frequency modes, namely,  AUTO ,   50Hz

a

 nd   60Hz

c an b

 e s elected f or a

 ll h

 armonic  

measurement functions respectively.U

  ser c an p

  ress H

  ARM k ey f or a

  l ong t ime t o a

  lter f requency  

mode temporarily during measurement. (Instrument will restore default mode after power-off.) 
Default frequency mode also can be set under setup mode. (Please refer to Clause 9.3: Default 
frequency mode setup for SE3 harmonic function for difference of 3 frequency modes.)

8.1 Total voltage harmonics for full wave distortion rate (V THD-R

It will measure and display effective value of total harmonics of single-phase voltage to full 
wave distortion rate, harmonic order and corresponding orders of harmonic voltage for load of 
three-phase four-wire system.

Measurement steps: Press HARM key to enter into measurement mode of total voltage 
harmonics to total wave distortion rate firstly after bootstrap and connect voltage signal of 
measured phase to voltage input end of instrument by probe and connect zero wire to COM 
end. As shown in Figure 14, connect phase wire to any port of V1/V2/V3 and press SELECT 
key so that measurement port can be consistent with input port.

As shown in Figure 21, LCD will display current harmonic order (with auxiliary display in left 
lower corner), total voltage harmonics for full wave distortion rate (with auxiliary display in right 
lower corner) and effective value of harmonic voltage (with main display in the middle) 
respectively.

Figure 21

User can press 

 key to increase harmonic order or press 

 key to reduce harmonic order. It 

also will display effective value of various voltage harmonic components correspondingly.

UT241/242/243 OPERATING MANUAL 

UT241/242/243 OPERATING MANUAL