Harrington Hoists and Cranes Series 3 End Truck - Manual (Page 49)

8.0 Troubleshooting
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HAZARDOUS VOLTAGES ARE PRESENT IN THE MOTORIZED END TRUCK AND IN CONNECTIONS
BETWEEN COMPONENTS.
Before performing ANY maintenance on the equipment, de-energize the electrical supply to the equipment,
and lock and tag the supply device in the de-energized position. Refer to ANSI Z244.1, “Personnel
Protection - Lockout/Tagout of Energy Sources.”
Only Trained and competent personnel should inspect and repair this equipment.
Table 8-1 Troubleshooting Guide
Trouble Cause Remedy
The crane does not move
smoothly. The end truck is not set at a right
angle to the bridge beam or the left
and right end trucks are not parallel
to one another. Set the end trucks at a right angle
to the bridge beam, and parallel
with one another.
Track wheels are unevenly worn. Replace the wheels where
necessary.
Runway span out of tolerance. Adjust runways where necessary.
See Table 2-1.
Brake force is unbalanced between
the left and right brakes. Adjust the left and right brakes.
A gap has formed between the
guide rollers and the runway rail.
May be due to wear in the guide
roller. Replace the guide rollers where
necessary.
Bumpers on the left and right
end truck do not contact the
end stops at the same time. The crane is not square. May be
due to bolts coupling the end truck
to the bridge beam are loose. Adjust so that contact is made at
the same time, and tighten bolts
where necessary.
The motor fails to turn and
makes a humming sound. The brake is not releasing. Check the brakes and wiring to
brakes.
Electronic soft start’s torque volume
is adjusted too low. Increase torque volume.
The electronic soft start is
damaged. Repair or replace the soft start
when necessary.
The motor gets extremely hot. The motor is running on a single-
phase condition. Repair wiring to restore 3-phase
operation.
Power supply voltage has dropped. Ensure power supply is at proper
voltage.
The brake circuit is disconnected. Repair wiring to restore brake
circuit.
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