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www.nieaf-smitt.com
Nieaf-Smitt is a brand name of Mors Smitt
5.15 Motors
1. AC-disconnect the motor from the line by
disconnecting the wires at the motor terminals or
by opening the main switch
2. If the main switch is used and the motor also has a
starter then the starter must be held, by some
means, in the ‘ON’ position
3. In the latter case, the measured resistance will
include the resistance of the motor, wire and all
other components between the motor and the main
switch
4. If a weakness is in dicated, the motor and other
components should be checked individually
5. If the motor is disconnected at the motor
terminals, connect one megohmmeter lead to the
grounded motor housing and the other lead to one
of the motor leads. Disconnect the motor from
the line
6. To test the brush rigging, field coils and armature
connect one megohmmeter lead to the grounded
motor housing and the other lead to the brush on
the commutator
7. If the resistance measurement indicates a
weakness, raise the brushes off the commutator
and separately test the armature, field coils and
brush rigging by connecting one megohmmeter
lead to each of them individually, leaving the other
connected to the grounded motor housing
8. The above also applies to DC generators
