Troubleshooting; Motor Troubleshooting Chart - ABB Low Voltage Motors Manuel D'installation, D'exploitation Et De Maintenance

9. Troubleshooting

These instructions do not cover all details or variations in equipment nor provide for every possible condition to be met
in connection with installation, operation or maintenance. Should additional information required, please contact the
nearest ABB Sales Office.

Motor troubleshooting chart

Your motor service and any troubleshooting must be handled by qualified persons who have proper tools and
equipment.
TROUBLE CAUSE
Motor fails to start Blown fuses
Overload trips
Improper power supply
Improper line connections
Open circuit in winding or control
switch
Mechanical failure
Short circuited stator
Poor stator coil connection
Rotor defective
Motor may be overloaded
Motor stalls One phase may be open
Wrong application
Overload
Low voltage
Open circuit
Motor runs and Power failure
then dies down
Motor does Not applied properly
not come up to
Voltage too low at motor terminals
nominal speed
because of line drop
Starting load too high
Broken rotor bars or loose rotor
Open primary circuit
ABB/Manual for Low Voltage Motors 01-2009
WHAT TO DO
Replace fuses with proper type and rating.
Check and reset overload in starter.
Check to see that power supplied agrees with motor rating plate and
load factor.
Check connections against diagram supplied with motor.
Indicated by humming sound when switch is closed. Check for loose
wiring connections.
Also ensure that all control contacts are closing.
Check to see if motor and drive turn freely. Check bearings and
lubrication.
Indicated by blown fuses. Motor must be rewound. Remove end
shields, locate fault.
Look for broken bars or end rings.
Reduce load.
Check lines for open phase.
Change type or size. Consult equipment supplier.
Reduce load.
Ensure the rating plate voltage is maintained. Check connection.
Fuses blown, check overload relay, stator and push buttons.
Check for loose connections to line, to fuses and to control.
Consult equipment supplier for proper type.
Use higher voltage or transformer terminals or reduce load. Check
connections. Check conductors for proper size.
Check the start load of the motor.
Look for cracks near the rings. A new rotor may be required, as
repairs are usually temporary.
Locate fault with testing device and repair.
EN-19