29
30
Wind the well-conducted bare wire around the exterior of inner insulation layer,
connect the safety terminal with the exterior conductor of inner insulation layer
in order to prevent current leakage at the surface of measured object. Surface
leakage current is conducted to the safety terminal, so as to eliminate the surface
leakage current at the measurement path between “+” and “-” poles, thus improving
the measurement accuracy, as shown in the figure below:
C. Ultra-high insulation resistance measurement with three-wire connection
Wind the well-conducted bare wire around the exterior of inner insulation layer,
connect the safety terminal with the exterior conductor of inner insulation layer
and the unused cable. Surface leakage current is conducted to the safety
terminal, so as to eliminate the surface leakage current at the measurement
path between “+” and “-” poles, thus ensuring the measured insulation
resistance is the insulation resistance between the selected cable and exterior
insulator, and eliminating the leakage path between cables, as shown in the
figure below:
Fig. 10.1.2 Three-wire connection
Black
Red
Green
Shield
B. High resistance measurement with three-wire connection
Fig. 10.1.3 Three-wire connection
10.2 . Transformer Insulation Resistance Testing
A. Testing of insulation resistance between primary winding and grounding of
secondary winding
Fig. 10.2.1 Connection of testing
Black
Red
Green
Shield
Black
Red
UT512D/E User Manual
UT512D/E User Manual
