44
Pub. 1147 - Rev. 7 SEPTEMBER 2004
Mechanical Dock Leveler Hydraulic Conversion
Problem
Probable Cause
Remedy
13. Fuse or circuit breaker frequently
a. Undersized fuse or circuit breaker.
a. Verify 20 Amp for 120VAC and 15 Amp
trips.
for 240VAC.
b. Low voltage.
b. Verify ±10% nominal voltage while unit
is running.
c. Short circuit in wiring.
c. Check wire connections and verify
wiring.
d. Wire gage is too small. Distance is too
d. Verify that minimum wire gage is 12
long.
AWG. See wiring charts.
e. There is more than one device on the
e. Verify that the leveler is the only device
circuit.
on the circuit breaker or fuse.
f. Motor failure.
f. Replace motor.
g. The solid-state motor controller has
g. Type 1 Control Box – Not applicable.
had an internal failure.
Type 2 Control Box – Replace solid-
state motor controller.
14. Options control box frequently goes
a. Pushbutton is being held too long.
a. Release pushbutton.
into a two minute time-out fault.
b. The pushbutton and/or contact block
b. Type 2 Control Box – Replace
does not function properly or is stuck.
pushbutton and/or contact block.
c. The ARTD system has failed.
c. Verify that ARTD and restrictor limit
switches are functional.Verify that
ARTD actuator assembly is functional.
15. Options Control Box frequently goes
a. Low voltage.
a. Verify ±10% nominal voltage while unit
into an overcurrent fault.
is running.
b. Short circuit in wiring.
b. Check wire connections and verify
wiring.
c. Wire gage is too small. Distance is too
c. Verify that minimum wire gage is 12
long.
AWG. See wiring charts.
d. There is more than one device on the
d. Verify that the leveler is the only device
circuit.
on the circuit breaker or fuse.
e. Motor failure.
e. Replace motor.
f. The solid-state motor controller has
f. Type 1 Control Box – Not applicable.
had an internal failure.
Type 2 Control Box – Replace solid-
state motor controller.
16. Type 2 Control Box frequently goes
a. The ARTD system has failed.
a. Verify that ARTD and restrictor limit
into an ARTD fault.
switches are functional. Verify that
ARTD actuator assembly is functional.
