Tips For Successful Insulation Resistance Testing; Insulation Measurement - Connections - AEMC 1015 User Manual

4.2.4

Tips For Successful Insulation Resistance Testing

• Check with the equipment manufacturer for factory insulation
resistance readings.
• Do not rely on insulation resistance testing alone as proof of wind-
ing conditions.
• Do not expect the same value for all parts of all machines.
• Observe consistent test time duration, recognizing that total
current through insulation under test will vary with time.
• Correct all readings properly to a standard reference temperature
(see IEEE Std. #43-1974, Temperature Correction Curve).
• Know what you are testing. Isolate the piece of equipment from
other circuitry.
• Watch trends rather than relying on single "spot" readings.
4.2.5

Insulation Measurement - Connections

Figure 3 shows the connections to measure the insulation of one conduc-
tor to the other conductors. The cable should be disconnected at both
ends to avoid leakage through switchboards and panels.
Megohmmeter Model 1015
Conductor Under Test
-
+
!
Battery
OFF
Check
MEGOHMMETER
AEMC
MODEL 1015
I N S T R U M E N T S
Figure 3
Cable Insulation
600V
6
MΩ - 500 V
MΩ - 1000 V
1000 Ω
10 Ω +
10 Ω −
11