Duke DU903, Operation Manual

Page: 31 / 38

Page 31
7-2 Troubleshooting
If the winch fails to start after several attempts or the hoist’s operation appears to
be defective check the following:
TROUBLE SHOOTING FOR CHAIN HOIST
Trouble Probable Cause Check and Remedy
1. Lifting motor does not
respond to pushbutton
A) Power failure in supply
line
A) Check circuit, breakers, switch
and connection in power supply
line
B) Wrong voltage or
frequency
B) Check voltage and frequency of
power supply against the rating
on the nameplate of the motor.
C) Improper connections in
chain hoist of push button
C) Check all connections at line
connectors and on terminal
block.
D) Brake does not release D) Check brake coil connection for
open or short circuit. Check
wiring for relay rectifier.
2. Hook does not stop
promptly
A) Chain hoist overloaded A) Reduce load within rated
capacity of chain hoist.
B) Brake not holding B) Check brake and it may be
necessary to replace discs.
3. Hook moves in wrong
direction
A) Improper connection A) Check all connections against
wiring diagram.
4. Chain hoist hesitates
to lift when energized
A) Chain hoist overloaded A) Reduce load within rated
capacity of chain hoist.
B) Worn overload limiting
clutch
B) Check and adjust limiting clutch
C) Low voltage C) Determine cause of low voltage
and bring up to within plus or
minus 10% of the voltage
specified on the motor. Measure
voltage at the lifting motor in
terminal block power input.
5. Hook raises but will
not lower
A) “Down” circuit open A) Check circuit for loose
connections.
B) Broken conductor in
pushbutton cable
B) Check each conductor in the
cable.
If one is broken, reduce entire
cable.