Upright ULII-25, Service & Parts Manual

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5-2 UL-25/32/40/48 Portable Personnel Lifts
Troubleshooting
Section
Table 5-1: Troubleshooting
Use minimum 12 ga. cord of 50 feet
(16m) or less in length.
Check all AC plugs and cords used.
Check power output at wall outlet.
Check the voltage output of the
Battery Charger. If less than 12 VDC,
repair or replace.
After completely charging Battery,
test Battery. Replace as required.
With the switch in the ON position,
check continuity across the contacts.
If none, replace.
Make sure all four outriggers are in
firm contact with floor. Check
continuity of interlock switches.
Test for continuity through cable
assembly and repair or replace.
While operating the Lift function,
check the voltage to the Electric
Motor. If voltage is present (12VDC
or 120/240VAC), replace the motor.
In case of low AC voltage, see #1.
Use minimum 12 ga. cord of 50 feet
(16m) or less in length.
Replace indicator light.
Replace switch.
Repair damage, insure proper
connection.
Close valve.
Check hydraulic fluid level, top off as
required.
Check or replace Down Valve (V2).
Adjust the Relief Valve (RV). If not
adjustable, replace.
Check or replace Lift Valve (V1).
Check pressure and delivery of the
Hydraulic Pump. Replace if required.
Lift Function
inoperable,
electric motor
does not start.
Lift turns on
and off
repeatedly.
One or more,
but not all
indicator lights
fail to operate
Lift function
inoperable,
Electric Motor
starts when
control is
activated.
TROUBLE PROBABLE CAUSE REMEDY TROUBLE PROBABLE CAUSE REMEDY
1. Extension cord too
long or insufficient
capacity.
2. Not plugged in or
faulty connection (AC
only).
3. No power at wall
outlet (AC only).
4. Faulty Battery Charger
(DC only).
5. Faulty Battery (BAT).
6. Key Switch (S2),
Emergency Stop
Switch (S1, S3) or
Push-button Switch
(S4, S5) failed open.
7. Outrigger Interlock
Switch (S7,S8, 9,S10).
8. Open circuit in cable
to motor control box.
9. Faulty Electric Motor
(M1).
1. Low line voltage or
battery charge.
1. Indicator light
damaged or faulty.
2. Outrigger limit switch
damaged or faulty.
3. Chassis harness
damaged or
improperly connected.
1. Emergency Lowering
Valve (V2) open.
2. Hydraulic Reservoir
Low.
3. Down Valve (V2)
stuck.
4. Relief Valve (RV) out
of adjustment or
faulty.
5. Lift Valve (V1) faulty.
6. Faulty Hydraulic
Pump (P).
5.1
Platform does
not lower using
electrical
switches.
(Will lower using
emergency
lowering valve.)
Platform does
not lower or
lowers very
slowly.
Platform
continues to
lower when
controls are
released.
1. Down Valve Solenoid
(SOL1) faulty.
2. Electrical malfunction.
1. Down Orifice (ORF)
plugged.
2. Down Valve (V2)
blocked or stuck
closed.
2. Mechanical
interference.
1. Down Valve (V1)
stuck open.
Test for continuity across Solenoid.
Repair or replace.
Check all AC plugs and cords used
(AC only). Check power output at
wall outlet (AC only).
With each switch (S1,S2,S3,S4,S6) in
the ON position, check continuity
across the contacts. If none, replace.
Remove and clean Down Orifice
check valve.
Check function / clear blockage of
Down Valve.
Inspect Mast Assembly, correct
interference.
Clean or replace Down Valve.