Electrical Faults - Siemens 1LA8 Operating Instructions Manual

8.11.2

Electrical faults

Note
If you are operating the motor with a converter, the operating instructions of the converter
must also be observed if electrical faults occur.
Table 8-1 Electrical faults
↓ Motor fails to start
↓ Motor accelerates sluggishly
↓ Rumbling noise during startup
↓ Rumbling noise during operation
↓ High temperature rise during no-load operation
↓ High temperature rise with load
X X X X
X
X X X X
X
X
X X X X
X X X
X
SIMOTICS TN Series N-compact 1LA8
Operating Instructions 05/2014
↓ High temperature rise of individual winding sections
Possible causes of faults
Overload
Interrupted phase in the supply cable
Interrupted phase in the feeder cable
after switching on
Mains voltage too low, frequency too high Check the power supply conditions.
Mains voltage too high, frequency too low Check the power supply conditions.
X Stator winding incorrectly connected
X Winding short circuit or phase short
circuit in stator winding
Incorrect direction of rotation
Remedial measures
Reduce the load.
Check the switches and cables.
Check the switches and cables.
Check the winding connection in the terminal box.
Determine the winding resistances and
insulation resistances. Carry out repair work after
consultation with the manufacturer.
Check the connection.
Operation
8.11 faults
97