Vestil EM1 series - Manual (Page 14)

03/05 03-126-120.doc
V ESTIL M FG . C O 14
T ROUBLESHOOTING G UIDE -- EM1-200 & -500, EHTT, EHTT-L
o
Warning: The load must be removed, and the platform either positively and adequately supported or fully tilted,
before any work is performed on the tilter.
Consult the factory for problems at time of installation, or for any problems not addressed below.
Problem: Possible cause(s): Action:
Power unit doesn’t run when “UP”
button is pressed.
Transformer fuse is blown.
No supply voltage.
Limit switch is engaged or bad.
Bad connection in control circuit.
Bad control transformer.
Open motor relay coil.
Test with meter; replace if bad.
Test with meter. Check fuses,
breakers, and overloads to
determine the cause.
Inspect and test switch. Replace if
bad.
Test all parts of circuit with meter.
Check for 24 VAC; replace if bad.
Test with meter; replace if bad.
Motor runs properly, platform
doesn’t move. Motor and pump
not noisy.
Motor rotation is wrong.
Pump has failed.
Fluid level is low.
Verify motor shaft rotates CCW.
Consult factory for replacement.
Ensure reservoir is filled to within
1” of the fill hole.
Motor or control enclosure hums,
chatters, or buzzes, or some type
of squeal can be heard; the
platform does not move, or the
platform moves only slowly..
See second item above, for when
platform doesn’t raise.
Excess voltage drop to motor, due
to power wire size too small, wire
run to long, or incoming voltage
too low.
Motor is “single-phasing” (three-
phase units only).
Pressure relief opening at full
pressure.
Same as above.
Check power installation for
adequacy. Check incoming
voltage while motor is running.
Correct problem found.
Determine cause of loss of voltage
on one phase; correct.
Check for structural damage.
Check for platform overload
condition.
Platform backstop drifts down. (EM1-200 only.) Contamination
holding open the lowering valve or
the check valve.
(EM1-500, EHTT, EHTT-L only.)
Counterbalance valve setting is
incorrect.
Remove and inspect. Clean per
instructions in this manual.
Increase the setting for
counterbalance valve “1CB” (turn
the socket-head screw CW).
Platform tilts down too quickly. (EM1-200 only.) Flow control spool
is stuck.
See below.
Platform tilts down too slowly. (EM1-200 only.) Flow control spool
is stuck.
Pinched hose.
Velocity fuse locking (platform only
very slowly creeps down).
(EM1-500, EHTT, EHTT-L only.)
Counterbalance valve setting is
incorrect.
Remove plug from FC port; push on
flow spool to ensure it is fully
pressed into the cavity.
Check pressure, supply, and return
hoses for kinks.
Same as for jerky platform motion.
Decrease the setting for
counterbalance valve “1CB” (turn
the socket-head screw CCW).
Platform won’t tilt down. Velocity fuse locking.
Control transformer fuse blown.
No supply voltage.
Valve solenoid is bad.
Bad connection in control circuit.
Physical blockage of the structure.
Solenoid valve or suction hose
screen plugged.
Same as for jerky platform motion.
Test with meter; replace if bad.
Test with meter. Check for cause of
power loss.
Check solenoid with multimeter on
diode-check function. (Reading
for ohms will not provide an
accurate test of the coil.)
Test all parts of circuit with meter.
Inspect for foreign material or
objects that might block the
platform.
Remove and inspect. Clean per
instructions in this manual.
Spongy or jerky platform motion. Excessive air in the hydraulic
cylinders.
(EM1-500, EHTT, EHTT-L.)
Counterbalance valve(s) setting is
incorrect.
Bleed air per procedure described in
this manual.
Consult the factory.