13
JLC680-2 Rev AA
April 2019
VI — TROUBLESHOOTING
Always disconnect unit from the power supply system before
removing hoist covers or the back cover of control station
Problem
Probable Cause
Remedy
Hook fails to stop
at end of travel
1. Limit switch not operating.
1. Check adjustment (See LIMIT SWITCH ADJUSTMENT, page 8). Check connections against
wiring diagram. Tighten loose connections or replace.
2. Brass limit switch nuts not moving on
shaft.
2. Check for stripped threads or bent nut guide.
3. Hoist reversing contactor malfunctioning.
3. Remove electrical cover and check reversing contactor.
Hoist does not
respond to
pushbutton
1. Power failure in supply lines.
1. Check circuit breakers, switches and connections in power supply lines.
2. Wrong voltage or frequency.
2. Check voltage and frequency of power supply against the rating on the nameplate of the motor.
3. Improper connections in hoist or
pushbutton station.
3. Check all connections at line connectors and on terminal block. Check terminal block on dual
voltage hoists for proper voltage connections.
4. Brake does not release.
4. Check connections to the solenoid coil. Check for open or short circuit. Check for proper
adjustment (See BRAKE ADJUSTMENT, page 9).
5. Faulty hoist reversing contactor
5. Check coils for open or short circuit. Check all connections in control circuit. Check for burned
contacts. Replace as needed.
Hook does not
stop promptly
1. Hoist overloaded.
1. Reduce load to within rated capacity of hoist.
2. Brake not holding.
2. Check brake adjustment (See BRAKE ADJUSTMENT, page 9). It may be necessary to replace
discs.
Hook moves in
wrong direction
1. Three phase reversal.
1. Reverse any two wires (except the green ground wire) at the power source (See INSTALLATION
3c, page 5).
2. Improper connections.
2. Check all connections against wiring diagram.
Hoist hesitates
to lift when
energized
1. Hoist overloaded.
1. Reduce load within rated capacity of hoist.
2. Motor brake requires adjustment.
2. Check motor brake adjustment (See BRAKE ADJUSTMENT, page 9)
3. Worn overload limiting clutch.
3. Replace clutch.
4. Low voltage.
4. 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 hoist reversing contactor while lifting a load.
5. Faulty SINPAC
®
starting switch or start
capacitor (single phase hoist only).
5. Replace faulty component
Hook raises but
will not lower
1. “DOWN” circuit open.
1. Check circuit for loose connections. Check “DOWN” limit switch for malfunction.
2. Broken conductor in pushbutton cable.
2. Check each conductor in the cable. If one is broken, replace entire cable.
3. Faulty hoist reversing contactor.
3. Check coils for open or short circuit. Check all connections in control circuit. Check for burned
contacts. Replace as needed.
4. Loose screw clamps.
4. Ensure that screw clamps are tightened on the terminal blocks and reversing contactor.
Hook lowers but
will not raise
1. Hoist overloaded.
1. Reduce load to within rated capacity of hoist.
2. Low voltage.
2. 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 hoist reversing contactor while lifting a load.
3. “UP” circuit open.
3. Check circuit for loose connections. Check “UP” limit switch for malfunction.
4. Broken conductor in pushbutton cable.
4. Check each conductor in the cable. If one is broken, replace entire cable.
5. Faulty hoist reversing contactor.
5. Check coils for open or short circuit, check all connections in control circuit. Check for burned
contacts. Replace as needed.
6. Faulty capacitor (single phase hoist only).
6. Check starting capacitor on motor. Replace if necessary.
7. Worn overload limiting clutch.
7. Replace overload clutch assembly.
8. Loose screw clamps.
8. Ensure that screw clamps are tightened on the terminal blocks and reversing contactor.
Failure to follow proper lockout/tagout procedures may
present the danger of electrical shock.
TO AVOID INJURY:
Disconnect power and lockout/tagout disconnecting means
before removing cover or servicing this equipment
