4 Troubleshooting
LS Open Loop Vector Motor 4H42, 4H71, 4H72 Manual Supplement
za-o.2.8.41-us-1.1
August 2022
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Troubleshooting
Fault
Possible cause
Measure
see the chapter/section
Wire rope hoist does not start,
motor hums
Not all current phases are
available
Check the fuses
Check supply line
Testing control and switching
devices
Wire rope hoist does not start
after prolonged downtime or
starts with difficulty, motor hums
Hoist motor brake is stuck.
Check the hoist motor brake.
Checking the hoist motor brake.
Loud “clack” noise when
switching on
Air gap too great.
Summary of Contents for 4H42
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