Unilock Troubleshooting - TPR UniLock Owner & User Manual

TROUBLESHOOTING

UniLock Troubleshooting

Unless the dock leveler is equipped with a tethered
remote, two people are required to engage the
maintenance prop: one person to operate the unit,
the other person to engage the maintenance prop.
In addition, it is recommended and good safety
practice to use an additional means to support
the dock platform and lip anytime when physically
working in front of or under the dock leveler. This
additional means may include, but is not limited to a
boom truck, fork truck, stabilizing bar or equivalent.
Before performing the detailed troubleshooting procedures, check the following items first:
• Check all fuses inside the control panel(s). Replace
any blown fuse(s) with a fuse of equal specification.
Symptom
UniLock vehicle restraint
lights do not flash, and
the hook does not raise.
UniLock vehicle restraint
lights are flashing, but
the hook does not raise
or lower to full extent.
32
Possible Cause
Power source malfunction.
Incorrect wiring.
Chain is loose or broken.
Low incoming voltage.
Drive motor faulty.
Incorrect wiring.
Incorrect brake torque.
When service under the dock leveler is required,
always lock all electrical disconnects in the OFF
position after raising the platform and engaging the
maintenance prop.
Always post safety warnings and barricade the
work area at dock level and ground level to prevent
unauthorized use of the dock leveler before
maintenance is complete.
A hard hat or other applicable head protection
should always be worn when working under or
around a dock leveler.
Always stand clear of platform lip when working in
front of the dock leveler.
• Make sure the correct voltages are present at the
proper locations inside the control panel(s).
Solution
Check for blown fuse at branch circuit disconnect.
Verify electrical schematics.
Adjust or replace as required.
Verify incoming power at L1 and L2.
Check motor, repair or replace.
Verify wiring per electrical schematic.
Brake torque should greater than 42 ft-lbs.
4111-0072 — Dec. 2018
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