Rockwell Automation 1329R Std. Industrial AC Induction Motors - Manual (Page 11)

Standard Industrial AC Induction Motors 11
Before starting the motor, check the following items:
• The rotor should turn freely when disconnected from the load.
• Driven machine should be unloaded when first starting the motor.
The motor should run smoothly with little noise. If the motor fails to
start and produces a decided hum, it may be that the load is too great
for the motor or that it has been connected improperly. Shutdown
immediately and investigate for trouble.
Drain Plugs
If motor is totally enclosed fan-cooled or non-ventilated, it is
recommended that condensation drain plugs, if present, be removed.
These are located in the lower portion of the end-shields. Totally
enclosed fan-cooled “XT” motors are normally equipped with
automatic drains which may be left in place as received.
Rotation
To reverse the direction of rotation, disconnect from power source
and interchange any two of the three line leads for the three-phase
motors.
Test for General Condition
If the motor has been in storage for an extensive period or has been
subjected to adverse moisture conditions, it is best to check the
insulation resistance of the stator winding with a megohmeter.
If the resistance is lower than one megohm the windings should be
dried in one of the two following ways:
1. Bake in an oven at a temperature not exceeding 90 degrees C (200
degrees F) until insulation resistance becomes constant.
2. With rotor locked, apply low voltage and gradually increase
current through windings until temperature (measured with a
thermometer) reaches 90 degrees C (200 degrees F). Do not
exceed this temperature.
Initial Lubrication
Allen-Bradley motors are shipped from the factory with the bearings
properly packed with grease and ready to operate. Where the unit has
been subjected to extended storage (6 months or more) the bearings
should be relubricated (regreasable type) prior to starting.