Poweramp PR SERIES HYDRAULIC - Manual (Page 38)

TROUBLESHOOTING
36 4111-0001 — Sept. 2010
Symptom Possible Cause Solution
Three-phase units only:
Platform does not rise.
Motor hums, but does
not run. No voltage is present on
one line.
NOTE: A motor that is
missing voltage on one line
is said to be single-phased.
Check for blown fuses at branch circuit disconnect.
Replace fuse. Determine cause of blown fuse.
Check motor starter as follows:
1. Disconnect wires at load side of starter.
2. Energize the starter.
3. Measure line-to-line voltage at line side of starter.
4. Measure line-to-line voltage at load side of
starter.
5. Line-side and load-side voltages should be
approximately the same. Replace starter if
voltage values are considerably different from
one another.
Check all wiring to motor for high resistance or no
connection.
Three-phase units only:
Platform does not rise.
Motor runs in reverse Phase reversed. Reverse any two legs at the branch circuit
disconnect.
Single-phase units only:
Platform does not rise.
Motor energizes, but
does not run. Line voltage too low. Check wiring to motor for high resistance. Check for
loose or corroded connections. Check if gauge of
wires to motor are of correct size and specification
for load requirement. Replace if necessary.
Defective motor centrifugal
switch. Replace motor.
Defective motor capacitor. Replace motor.
Dock leveler equipped
with ARTD: Platform
does not automatically
return to the
cross-traffic position or
operates abnormally. The auto return proximity
switch not sensing target
correctly. Adjust proximity switch and target as necessary. See
Adjust Auto Return To Dock (ARTD) in the
Adjustment section.
Defective proximity switch. Replace switch.
Broken wire. Loose or
corroded wire connections. Repair or replace wires and connections as
necessary.