Poweramp CHALLENGER HYDRAULIC 11_96 - Manual (Page 18)

Always barricade the work area to prevent unauthorized use of the unit during repair or mainte-
nance procedures.
Always lock OFF all electrical disconnects when servicing the unit. Always stand clear of the
dockleveler lip when working in front of the unit.
Perform the following procedures prior to beginning detailed troubleshooting:
A. Check all fuses inside the control assembly(s). Replace any bad fuse with one of
equivalent specification.
B. Confirm presence of necessary voltages inside the control assembly(s).
WARNING
TROUBLESHOOTING GUIDE
17
DOCK LEVELER
Problem Cause(s) Solution
Leveler does not operate.
Motor does not energize 1. Motor overload device
tripped. 1. Reset Overload relay (3 phase) or replace fuse(s) (1
phase). Determine cause of device tripping. NOTE: If
replacing fuse(s), replace with device of equal
specifications.
2. Motor starter (3 phase) or
motor relay (1 phase) not
energizing. 2. Check voltage at starter or relay coil. If voltage is
present and starter or relay does not energize then
replace device. If voltage is not present check all
components in series with the starter or relay coil for
proper operation.
Leveler does not operate.
Motor energizes but does not
run (motor hums, overload
device should trip). 1. 3 phase units only - voltage
at one line is absent (motor
being single phased). 1A. Fuses at motor branch circuit overcurrent device only
- check for tripped fuse. Replace fuse. Determine cause
of fuse tripping.
1B. Check motor starter for component failure.
Disconnect wires at load side of starter. Use voltmeter to
read line-to-line voltages at line side and load side of
starter when starter is energized. Line side and load side
voltage values should be nearly identical. Replace starter
if values not identical.
1C. Check all wiring to motor for high resistance (loose)
or no connection.
2. 1 phase units only - motor
centrifugal switch faulty. 2. Replace motor.
Leveler will not raise. Pump
operates in pressure relief. 1. Load on platform. 1. Remove load. Unit is designed to raise no more than its
own weight as a safety feature.
Leveler operates slowly. 1. Low hydraulic fluid. 1. Add fluid. See Preventive Maintenance section, page
14.