Diagnostics and fault elimination
Malfunctions
If faults occur during the operation of the drive, the table below helps you to identify the
causes. If it is not possible to remedy the fault using the measures listed, please contact the
Lenze service department.
Error
Possible causes
Remedy
Motor too hot
Can only be evaluated by measuring the surface
temperature:
•
Non-ventilated motors >140 °C
•
Externally ventilated or self-ventilated motors
> 110 °C
Insufficient cooling air, blocked air ducts.
Ensure unimpeded circulation of cooling air
Preheated cooling air
Ensure a sufficient supply of fresh cooling air
Overload, with normal mains voltage the
current is too high and the speed too low
Use larger drive (determined by power
measurement)
Rated operating mode (S1 to S8 IEC/EN
60034-1) exceeded
Adjust rated operating mode to the specified
operating conditions. Determination of correct
drive by expert or Lenze customer service
Loose contact in supply cable (temporary
single-phase operation!)
Tighten loose contact
Fuse has blown (single-phasing!)
Replace fuse
Overload of the drive
Check load and, if necessary, reduce by means
of longer ramp-up times
Check winding temperature
Heat dissipation impeded by deposits
Clean surface and cooling fins of the drives
Motor suddenly stops and does not restart
Overload monitoring of the inverter is activated Check inverter settings
Reduce load caused by longer acceleration
times
Incorrect direction of rotation of the motor,
correct display on the inverter
Motor cable with reverse polarity
Check and correct polarity
Polarity of encoder cable reversed
Motor rotates normally but does not reach the
expected torque
Motor cable interchanged cyclically
Not all motor phases connected
Connect the phases at the motor cable
connection correctly
Motor turns in one direction at maximum speed
in an uncontrolled manner
Motor cable interchanged cyclically
Check motor connection and, if necessary,
correct
Polarity of encoder cable reversed
Check encoder connection and, if necessary,
correct
Motor slowly rotates in one direction and is not
influenced by the inverter
Polarity of motor cable and encoder cable
reversed
Check and correct polarity
Irregular running
Insufficient shielding of motor or resolver cable Checking shielding and earth connection
Inverter gain too large
Adjust the gains of the controllers (see
operating instructions for the inverter)
Vibrations
Insufficiently balanced coupling elements or
machine
Rebalance
Inadequate alignment of drive train
Realign machine unit, check foundation, if
necessary.
Loose fixing screws
Check and tighten screw connections
Running noises
Foreign particles inside the motor
Repair by the manufacturer, if necessary
Bearing damage
Surface temperature > 140 °C
Overload of the drive
Check load and, if necessary, reduce by means
of longer ramp-up times.
Check winding temperature
Heat dissipation impeded by deposits
Clean surface and cooling fins of the drives.
Diagnostics and fault elimination
Malfunctions
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