User Manual

40
ELECTRIC MOTOR TROUBLESHOOTING GUIDE
PROBLEM POSSIBLE CAUSES REMEDY
Noisy Bearings
(listen to bearings
for the following)
Smooth Mid-Range Hum Normal Fit. Bearing OK.
High Whine Internal fit of bearing too tight. Replace bearing -check fit.
Low Rumble Internal fit of bearing too loose. Replace bearing -check fit.
Rough Clatter Bearing Destroyed. Replace bearing -Avoid:
a. Mechanical Damage.
b. Excessive Greasing.
c. Wrong Grease.
d. Solid Contaminants.
e. Water running into motor.
f. Misalignment on close
coupled application.
g. Excessive belt tension.
High Input Current (all Accuracy of ammeter readings First check accuracy of
three phases) ammeter readings on all three
phases.
Running Idle High Une Voltage Consult power company.-
(disconnected from 5 to 10% over nameplate. possibly decrease by using
load) lower transformer tap.
Running Loaded Motor Overloaded. Reduce load or use larger
motor.
Motor voltage rating does not Replace motor with one of
match power system voltage. correct voltage rating.
Consult power company -
possibly correct by using a
different transformer tap.