VRC Series IOM
14
IOM-M2-0316
Technical Support: (800) 789-8550
Part Number 478603
Troubleshooting
Motor
Motor Symptom
Probable Cause
Action
Motor doesn't start
Blown fuse or open circuit breaker
Replace fuse or reset circuit breaker
Overload trips
Check and reset overload
Improper line connections
Check connections on diagram supplied with motor
Open circuit in winding or starting switch; humming
sound from motor when switch is closed
Replace motor
Improper current supply
Check that power supply agrees with motor specifications
listed on nameplate
Mechanical failure
Determine that motor turns freely; if not, replace motor
Motor overload
Reduce load
Power source (3-phase) may have
one phase open
Check line for open phase
Motor doesn't come up
to speed
Motor under-designed for the application
Replace with larger motor
Voltage too low at motor terminals
Check across AC line and correct if possible
Line wiring to motor too small
Install larger wiring
60-Hz motor connected to 50-Hz line supply
Replace unit with 50-Hz motor
Motor wired for wrong voltage
Check wiring
Motor takes too long to
accelerate to speed
Excessive load
Consult the factory
Loose connection(s)
Check connection and tighten where necessary
Motor rotates in
wrong direction
Improperly wired to AC line;
wrong sequence of phases
Check wiring diagram on motor nameplate and correct;
reverse any two motor leads at line connection
Motor vibrates excessively
Motor mounting bolts are loose
Tighten mounting bolts
Propeller is unbalanced
Replace propeller
Motor overheats
Motor overloaded
Replace with larger motor
Motor fan may be clogged with dirt,
preventing proper ventilation
Remove fan cover and clean; replace fan cover
Motor (3-phase) may have one phase open
Check that all connections are tight
Line voltage too high
Check across AC line. Consult power company;
step-down transformer may be required.
Line voltage too low
Check across AC line. Consult power company;
step-up transformer may be required.