PROBLEM
PROBABLE CAUSE
SOLUTION
TROUBLE SHOOTING GUIDES
ELECTRIC MOTORS
Dies Down
of main power supply
Stator shorts when motor
Replace stator
warms up.
Motor Does Not Come Up Motor under designed for
Replace with a larger motor
to Speed
application
Voltage too low at motor
Check across AC line and correct if possible
terminals
Line wiring to motor too small
Install larger line wiring
Broken rotor bars
Look for broken bars or end rings, replace motor.
60 cycle motor connected to
Replace unit with a 50 cycle motor.
50 cycle line supply
Motor Takes Too Long
Excessive load
Replace with larger motor
to Accelerate
Loose connection(s)
Check connections and tighten where necessary
Wrong Rotation
Improperly wired to AC line
Check wiring diagram on motor nameplate and correct.
(3 Phase)
(Wrong sequence of phases)
Reverse any two motor leads at line connection
Motor Overheats
Motor overloaded
Replace with larger motor.
(Temperature Rise Above
Ambient Greater Than
Motor fan may be clogged with
Remove fan cover and clean, replace fan cover
Nameplate Specifications) dirt preventing proper
ventilation
Motor (3 phase) may have
Check to insure that all connections are tight
one phase open
Partially shorted stator coil
Must be rewound
Line voltage too high
Check across AC line and correct. Step-down
transformer may be required
Motor Overheats
Line voltage too low
Check across AC line. Consult power company.
-Continue-
Step-up transformer may be required
