Parker NX Series, Technical Manual

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115 - PVD 3663_GB_NX_March 2017.Docx
4.5. Troubleshooting
Some symptoms and their possible causes are listed below. This list is not
comprehensive. Whenever an operating incident occurs, consult the relevant servo
drive installation instructions (the troubleshooting display indications will help you in
your investigation) 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 there is no mechanical blockage or if the motor
terminals are not short-circuited.

Check the power supply to the brake.
You have difficulty
starting the motor or
making it run

Check on the fuses, the voltage at the terminals (there
could be an overload or the bearings could be jammed),
also checks on the load current.

Check the power supply to the brake (+ 24 V ± 10 %) and
its polarity.

Check on any thermal protection, its connection and how
it is set in the drive.

Check on the servomotor insulation (if in doubt, carry out
hot and cold measurements).
The minimum insulation resistance value measured under a
max. 50V DC is 50 MΩ:

Between the phase and the casing

Between the thermal protection and the casing

Between the brake coil and the casing

Between the resolver coils and the casing.
You find that the motor
speed is drifting

Reset the offset of the servoamplifier after having given a
zero instruction to the speed setpoint input.
You notice that the
motor is racing

Check the speed setpoint of the servo drive.

Check you are well and truly in speed regulation (and not
in torque regulation).

Check the encoder setting

Check on the servomotor phase order: U, V, W
You notice vibrations

Check the encoder and tachometer connections, the
earth connections (carefully) and the earthing of the earth
wire, the setting of the servo drive speed loop, tachometer
screening and filtering.

Check the stability of the secondary voltages.

Check the rigidity of the frame and motor support..