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4.5.  Troubleshooting 
We provide hereunder a symptom list in regard with their possible cause. This is not an 
exhaustive list so in case of trouble, please refer to the associated inverter manual (the 
diagnostic board indications will help you investigating) or contact us at: 
http://www.parker.com/eme/repairservice. 
You note that the 
motor does not turn by 
hand when the motor 
is not connected to the 
drive. 
  Check if the phases are not in short circuit. 
  Check  if  the  rotor  is  externally  blocked  mechanically  in 
rotation.  
You have difficulty 
starting the motor or 
making it run 
  If there is a thermal protector, check it and its connection 
and how it is set in the drive. 
  Check the servomotor insulation (in doubt, measure when 
the motor is hot and cold. 
The minimum insulation resistance measured under 500VDC 
max is 50 MΩ : 
-  Between phase wire and housing, 
-  Between thermal protector and housing, 
-  Between resolver winding and housing. 
You find that the motor 
speed is drifting 
  Adjust the inverter offset. 
You notice that the 
motor is racing 
  Check the speed set-point of the inverter. 
  Check you are well and truly in speed regulation (and not 
in torque regulation). 
  Check the (feedback device) setting 
  Check  the  (feedback  device)  connections,  the  earth 
connections (carefully) and the earthing of the earth wire, 
the setting of the inverter. 
  Check the stability of the secondary voltages. 
  Check the rigidity of the frame and motor support. 
  Check motor fixing on its base. 
  Check the balancing. 
  Check the alignment between motor and load. 
You find that the motor 
is too noisy 
Several possible explanations :  
-  Unsatisfactory mechanical balancing, 
-  Defective coupling, 
-  Loosening of several pieces, 
-  Poor adjustment of the inverter of the position loop: 
check rotation with the loop open. 
-  Low drive switching frequency.