Megohmmeter Models 5000N/5100/5110
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Insulation Resistance Measurements on Motors
Figure 17 shows reading the
resistance to ground of a
three-phase motor winding.
Since the three-phase motors
are internally connected, it is
only necessary to connect one
lead to the motor lead and the
other lead to the motor frame
as shown.
Figure 17
Figure 18 shows the
windings of a three-phase
motor separated. Sometimes
this can be done at the lead
terminals while other times
the end bells must be
removed to get at the lead
wires of the coils. By
connecting the megohm-
meter as shown, the phase
insulation resistance value
can now be determined.
Read between phases “A”
and “B”, then “B” and “C”,
then “C” and “A”.
Figure 18
+ EARTH
- LINE
MEGOHMMETER
GUARD
+ EARTH
— LINE
MEGOHMMETER
GUARD
A
B
C
Summary of Contents for 5000N
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