8.9.2 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
  ↓ High temperature rise of individual winding sections
  Possible causes of faults Remedial measures
X X   X   X   Overload Reduce the load.
X             Interrupted phase in the supply cable Check the switches and cables.
  X X X   X   Interrupted phase in the feeder cable af‐
ter switching on
Check the switches and cables.
  X           Mains voltage too low, frequency too high Check the power supply conditions.
        X     Mains voltage too high, frequency too low Check the power supply conditions.
X X X X     X Stator winding incorrectly connected Check the winding connection in the terminal box.
  X X X     X Winding short circuit or phase short cir‐
cuit in stator winding
Determine the winding resistances and insulation 
resistances. Carry out repair work after consulta‐
tion with the manufacturer.
          X   Incorrect direction of rotation Check the connection.
Operation
8.9 faults
SIMOTICS TN Series N-compact  1LA8
Operating Instructions 05/2016 93