Vestil WL-100 series - Manual (Page 14)

14
TROUBLESHOOTING GUIDE - WL-100
§ WARNING: Care should be taken to identify all potential hazards and comply with all applicable safety procedures before beginning
troubleshooting or repairs.
§ CAUTION: Before performing any troubleshooting or repairs, the load must be removed from the platform. Then either raise the
platform and install the maintenance props, or fully lower the platform to the floor.
§ Only qualified individuals trained to understand mechanical devices and their associated electrical and hydraulic circuits, along with
the hazards that could result from them, should attempt troubleshooting and repair of this equipment.
Consult the factory for any problems not addressed in this manual.
Problem: Possible cause(s): Action:
Power unit doesn’t run when “UP” Transformer fuse is blown. Test with meter; replace if bad.
button is pressed. No supply voltage. Test with meter. Check fuses,
breakers, and overloads to determine
the cause.
Upper-travel limit switch or wiring Check connections to switch. Inspect,
is not connected; switch is engaged, test switch. Replace if bad.
or bad.
Overload relay is tripped.
Press reset button on overload relay.
Control transformer failed. Check for 24 VAC; replace if bad.
Motor relay coil failed. Test with meter; replace if bad.
Motor runs, platform doesn’t move. Motor rotation is wrong. Verify motor runs CW at the fan end.
Power unit not noisy. Pump is failing to build pressure. Consult factory.
Lowering valve’s manual operator is open. The manual operator should be pushed
down and rotated clockwise.
Motor hums or pump squeals, but the See last paragraph, above. Same as above.
platform does not move, or the Excess voltage drop to motor; due to Check power installation for adequacy.
platform moves only slowly. power wire size too small, wire run too Check incoming voltage while motor
long, or incoming voltage too low. is running. Correct problem found.
Motor is “single-phasing.” Determine cause of loss of voltage on
one phase; correct.
Pressure relief opening at full pressure. Check for structural damage or binding
of the scissor legs, etc.
Check for platform overload condition.
Contamination holding open the Remove and inspect. Clean per
lowering valve or the check valve. instructions in “Power Unit Operation.”
Lowering valve’s manual operator is open. The manual operator should be pushed
down and rotated clockwise.
Platform raises, then drifts down. See last two paragraphs, above. Same as above.
Spongy or jerky platform movement. Excessive air in the hydraulic cylinders. Bleed air per the procedure described in
“Power Unit Operation.”
Platform won’t lower. Toe guard switch or wiring is not connected; Check for a toe guard extrusion or
switch is engaged, or bad.
rubber corner that is stuck; adjust if
necessary. Inspect, test switches and
wiring with meter; replace if bad.
Solenoid coil is bad. Check with multimeter on diode-check
function. (Reading for ohms will not
provide an accurate test of the coil.)
Physical blockage of the structure. Inspect for foreign material or objects
that might block the leg set or its
rollers.
Solenoid valve is plugged. Remove and inspect. Clean per
instructions in “Power Unit Operation.
Platform lowers too slowly. Pinched hose. Check pressure hose for kinks.
Velocity fuse locking (platform only Same as for jerky platform movement.
slowly creeps down).
Flow control valve sticking.
Remove and inspect. Clean per
instructions in “Power Unit Operation”.
Platform lowers too quickly. See last paragraph, above. Same as above.
CAUTION: Do not use brake fluid or jack oils in the hydraulic system. If oil is needed, use an anti-wear hydraulic oil with a
viscosity grade of 150 SUS at 100°F (ISO 32 at 32°C) or a non-synthetic transmission fluid.