UNI-T UT255A Operating Manual page 14

Locate conductor to be measured at the center of clamp guide zone after
normally power on, see Figure A. Guide zone should be kept perpendicular
to the conductor when moving the meter forward to completely enclose it. If
OL A displays on LCD, it indicates that measured current is out of limit
and requires higher range or choose another meter, then if disconnecting the
conductor with the meter, pull back the meter (see Figure C) and try to keep
the conductor perpendicular to the guide zone during this operation.
The Conductor
Pull Forward
Guide Zone
Figure A
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Pull Back
Figure B Figure C
Measuring Leakage
Current of Zinc Oxide
Arrester
Ground Terminal
High-Voltage
Terminal
Grounding
Measuring Current in
High-Voltage Circuit
Measuring Current in
Low-Voltage Circuits
Ground Leakage
Current Testing
Grounding
Grounding
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