Troubleshooting - ABB MT Série Manuel D'installation, D'exploitation Et De Maintenance

10. Troubleshooting

These instructions do not cover all details or variations
in equipment nor provide information for every possible
condition to be met in connection with installation,
operation or maintenance. Should additional information be
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 the 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 Not applied properly
accelerate 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
Standard_Manual_LV_Motors_ML_revF_Book.indb 19
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 and 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 and 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, fuses and 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 motor's starts against "no load".
Look for cracks near the rings. A new rotor may be required, as
repairs are usually temporary.
Locate fault with testing device and repair.
Low voltage motors manual, 3GZF500730-85 Rev F 02-2015 | ABB Motors and Generators 19
6/2/2015 6:44:26 PM