Defect rotor / broken rotor bars Check the broken bars and end
rings.
Winding / phase short circuit Motor overhaul is needed
Overheating of the machinery
du
ring operation with load
Overload Reduce the load
Cooling is prevented by dust
accumulation
Ensure proper cooling and
cleanliness
Interruption of one phase Check connection and switches
Short circuit on the ground Repair in workshop needed
Imbalance of the power supply Check the cables and
transformer for faults
Motor vibrations Wrong allignment Allign the motor
Substrucutre is unstable Reinforce substructure
Imbalance in clutch / gearbox Balance clutch / gearbox
Imbalance in driven machinery Re-balance the machinery
system
Defect bearing Exchange the bearing
Multi-phase motor runs single-
phase
Check the circuit
Operation noise Circulating parts grinding Correct the mounting
Winding / phase short circuit Motor overhaul
Interruption of one phase Check connection and switches
High bearing temperature Motor shaft bent or damaged Straighten or replace the shaft
Wrong belt drive Reduce belt tension, arrange
pulley closer to the bearing
Wrong allignment Allign the machinery
Inadequate / excess grease Note the amount of re-grease
Table 9. Troubleshooting
SEVA-tec GmbH - Lether Gerwerbestrasse 10 - 26197 Ahlhorn - www.seva-tec.de
14
Failure Cause Actions
The machinery doesn’t start Overload Reduce the load
Wrong stator connection Check the connection
Fault power supply Check that power supply
complies with information on
nameplate
Interruption of one phase Check connection and switches
Mechanical fault Check that motor rotates
freely. Check the bearing and
lubrication.
Rotor defect Check the broken bars and end
rings.
Fuses burnt Use suitable fuses
The machinery is accelerating
slow / doesn’t accelerate
Load inertia at start to high Reduce the load
Under-voltage at motor
terminals due to the voltage
drop
Use higher voltage or higher
tran
sformer stage or reduce
the load. Use appropriate cable
cross-section.
9. Troubleshooting
Table 9 addresses the causes of errors that may occur and the action to be taken. All procedures are
only allowed to be carried out by qualified personnel using suitable tools and instruments.
For further information please contact SEVA-tec GmbH.
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