Watts R14-03-1WM - Manual (Page 15)

MOTOR TROUBLE SHOOTING CHART
TROUBLE CAUSE WHAT TO DO
Motor fails to start Blown fuses Replace fuses with proper type and rating
Overload trips Check and rest overload in starter.
Improper power supply Check to see that power supplied agrees with motor
nameplate and load factor.
Open circuit in winding or control switch Indicated by humming sound when switch is
closed.
Mechanical failure Check to see if motor and drive turn freely. Check
bearing and lubrication.
Short circuited stator Indicated by blown fuses. Motor must be rewound.
Poor stator coil connection Remove end bells, locate with test lamp.
Rotor defective Look for broken bars or end ring.
Motor may be overloaded Reduce load.
Motor Stalls One phase connection Check lines for open phase.
Wrong application Change type or size. Consult manufacturer.
Overload motor Reduce load.
Low motor voltage See that nameplate voltage is maintained. Check
connection.
Open circuit Fuses blown, check overload relay, stator and push
buttons.
Motor runs and then dies
down Power failure Check for loose connections to line, to fuses and to
control.
Motor does not come up Not applied properly Consult supplier for proper type.
to speed Voltage too low at motor terminals because of line
drop. Use higher voltage on transformer terminals or
reduce load. Check connections. Check conductors
for proper size.
Broken rotor bars or loose rotor. Look for cracks near the rings. A new rotor may be
required as repairs are usually temporary.
Motor takes too long to Open primary circuit Locate fault with testing device and repair.
accelerate Excess loading Reduce load.
Poor circuit Check for high resistance.
Defective squirrel cage rotor Replace with new rotor.
Applied voltage too low Get power company to increase power tap.
Wrong rotation Wrong sequence of phases reverse connections at motor or at switchboard.
Motor overheats while Overloaded reduce load.
running under load Frame or bracket vents may be clogged with dirt and
prevent proper ventilation of motor. Open vent holes and check for a continuous stream
of air from the motor.
Motor may have one phase open Check to make sure that all leads are well
connected.
Grounded could Locate and repair.
Unbalanced terminal voltage Check for faulty leads, connections and
transformers.
Motor vibrates after motor misaligned Realign
correcting have been Weak support Strengthen base.
made Coupling out of balance Balance coupling.
Driven equipment unbalanced Rebalance driven equipment.
Defective ball bearing Replace bearing.
Bearing not in line Line properly.
Balancing weights shifted Rebalance motor.
Polyphase motor running single phase Check for open circuit.
Excessive end play Adjust bearing or add washer.