Troubleshooting
91
300314330_002_C7 - 05/2021 - © Leybold
Error
message
Brief
Description AL FLT Possible cause
Corrective Action
to
or
Output
Phase Loss
n
Output cable is disconnected or the
motor winding is damaged.
Loose wires at the frequency converter
output.
Motor is too small (less than 5% of fre-
quency converter current).
Check the motor wiring.
Make sure all terminal screws in the frequency
converter and motor are properly tightened.
Check the motor and frequency converter
capacity.
to
or
Overcurrent
n
Short circuit or ground fault on the fre-
quency converter output side
The load is too heavy.
The accel./decel. times are too short.
Wrong motor data or V/f pattern set-
tings.
A magnetic contactor was switched at
the output.
Check the output wiring and the motor for
short circuits or broken insulation. Replace the
broken parts.
Check the machine for damages (gears, etc.)
and repair any broken parts.
Check the frequency converter parameter set-
tings.
Check the output contactor sequence.
to
or
Heatsink
Overheat
n
n
Surrounding temperature is too high.
The cooling fan has stopped.
The heatsink is dirty.
The airflow to the heatsink is restricted.
Check the surrounding temperature and install
cooling devices if necessary.
Check the frequency converter cooling fan.
Clean the heatsink.
Check the airflow around the heatsink.
to
or
Motor
Overload
n
The motor load is too heavy.
The motor is operated at low speed
with heavy load.
Cycle times of accel./ decel. are too
short.
Incorrect motor rated current has been
set.
Reduce the motor load.
Use a motor with external cooling and set the
correct motor in parameter L1-01
Check the sequence.
Check the rated current setting.
to
or
Drive
Overload
n
The load is too heavy.
Too much torque at low speed.
Check the load.
The overload capability is reduced at low
speeds. Reduce the load or increase the fre-
quency converter size.
