Vestil LDLT series - Manual (Page 7)

7
TROUBLESHOOTING GUIDE, DC UNITS - HT, LDLT
Before performing any task, always lower the table entirely.
Care should be taken to identify all potential hazards and comply with applicable safety procedures before beginning.
Only qualified individuals trained to understand mechanical devices and their associated electrical and hydraulic
circuits should attempt troubleshooting and repair of this equipment.
Consult the factory for any problems not addressed in this manual.
* Check the DC notes page for other troubleshooting notes specific to battery-powered units.
Problem:
1. Power unit doesn't run when "UP"
button is pressed.
2. Motor runs, but table does not move
or only moves slowly. Power unit not
noisy.
3. The power unit runs but makes a
higher-pitched sound; the table does
not move, or the table moves only
slowly.
4. Table raises, then drifts down.
5. Spongy or jerky table movement.
6. Table lowers too quickly.
7. Table won't lower.
8. Table lowers too slowly.
Possible Causes:
A. Upper-travel switch is engaged or
bad.
B. Push-button control cord not plugged
into motor relay assembly properly.
C. Bad motor relay assembly (green
LED not lit at all or turns off when the
motor relay pulls in).
D. Battery voltage low (green LED turns
off as or just after the motor relay
pulls in).
A. Pump is failing to build pressure.
B. Contamination holding open the
lowering valve or the check valve.
A. Pressure relief opening at full
pressure.
A. Contamination holding open the
lowering valve or the check valve.
A. Excessive air in the hydraulic
cylinder.
A. Flow control spool sticking.
A. Solenoid coil is bad.
B. Physical blockage of the structure.
C. Solenoid valve or suction hose
screen plugged.
A. Pinched hose.
B. Flow control spool sticking.
C. Velocity fuse locking (table only
slowly creeps down).
Action:
A. Inspect and test switch. Replace if
bad.
B. Verify that the push-button cable's
plug is connected properly to the
relay assembly's quick-connect.
C. Check for green LED on relay. Consult
the factory.
D. Test with meter. Charge battery if
low (< 12 volts). A fully charged
battery has 12.6 volts.
A. Consult the factory.
B. Remove and inspect. Clean per
instructions in this manual.
A. Check for structural damage or
binding of the posts, etc.
B. Check for table overload condition.
A. Remove and inspect. Clean per
instructions in this manual.
A. Bleed air from the bleeder valve at
the top of the cylinder.
A. Remove plug from FC port; push on
edge of flow spool to ensure it is fully
pressed into the cavity. Pull and
clean spool if dirty.
A. Check with multimeter on diodecheck
function. (Reading for ohms will not
provide an accurate test of the coil.)
B. Inspect for foreign material or
objects that might obstruct the table
or guide posts.
C. Remove and inspect. Clean per
instructions in this manual.
A. Check pressure, supply, and return
hoses for kinks.
B. Remove plug from FC port; push on
flow spool to ensure it is fully pressed
into the cavity. Pull and clean spool
if dirty.
C. Same as for jerky table movement.