33

34

7.8 Phase Sequence Detection

1

As shown in Figure 14, press MENU to select gear of 

voltage (V)+voltage (V)+voltage 

     (V)

. Insert red testing pen into 

V1

 jack, blue testing pen into 

V2

 jack, yellow 

     testing pen into 

V3

 jack and black testing pen into 

COM

 jack and connect 4 

     testing pens to measured power, three-phase load and grounding end.

Figure 14

1

As shown in Figure 15, 16 &17, instrument will display phase sequence detection result for 

     load loop of three-phase four-wire system.

Figure 15 Any phase of voltage 
is less than 30V.

Figure 16 Inverted sequence

Figure 17 Positive sequence

2

Positive sequence layout is shown in following figure. As shown in Figure 18, LCD can 

     display positive sequence detection result when connecting  V1,

V 2 and   V3  jacks t o

     Phase A, B & C if three-phase voltage exceeds 50V.

Positive 

sequence 

Figure 18

UT241/242/243 OPERATING MANUAL 

UT241/242/243 OPERATING MANUAL