Diagnostics And Fault Elimination - Lenze G7 Series Mounting And Switch-On Instructions

Diagnostics and fault elimination

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