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Systems Descriptions
Hydraulic Platform Sensor
Pressure Switch:
VL917 lift
models are equipped with a
hydraulic platform sensor
pressure switch. The hydraulic
pressure switch senses weight
on the platform and prohibits
the platform from folding when
a passenger is on the platform.
The platform sensor pressure
switch is mounted to the hy-
draulic pump. This switch is
activated when weight is on the
platform. This opens the circuit
and prevents the platform from
folding if the FOLD (In) switch is
pressed. When there is no load
on the platform, the platform
sensor pressure switch com-
pletes the circuit and allows the
platform to be folded when the
FOLD (In) switch is pressed.
Note:
The pressure switch is
also activated when the platform
folds to the stowed position
(shuts pump motor off).
Hydraulic
Pressure Switch
3/32" Hex Drive
Adjustment Screw
Improper hydraulic
pressure switch
adjustment may
result in serious
bodily injury and/or
property damage.
WARNING
K
1. Empty platform will not fold or there is excessive
intermittent pump operation during the fold cyle.
2. Pressure switch replacement.
3. Mechanical adjustment to and/or replacement of
lift components that may affect the amount of
hydraulic force required to fold the platform.
When to Adjust the Platform Sensor Pressure
Switch:
Hydraulic platform sensor pressure switches are
factory set and should require no adjustment (under
normal conditions). The conditions listed at right
indicate the need to adjust the pressure switch.
Refer to the switch adjustment instructions provided.
Pressure Switch Adjustment Instructions:
1. Unfold and lower the platform to the ground.
Place a 75 pound load in the center of the
platform and raise the platform to floor level.
2. Press the IN (Fold) switch. If the pump shuts off
and the platform does not fold, proceed to Step
3. If the platform starts to fold and the pump
does not shut off, or skips (cycles on and off),
proceed to Step 4.
3. Although the pump shut off and the platform did
not fold, you must ensure that the pressure
switch is set correctly so there is no hesitation
when folding an empty platform. Using a 3/32"
hex drive, turn the adjustment screw clockwise
1/16 to 1/8 turn at a time.
Note:
Press the OUT
(Unfold) switch to return the platform to floor
level before each adjustment. Press the IN
(Fold) switch to test operation following each
adjustment. Repeat until the pump starts cycling
on and off, folding the platform.
Return the platform to floor level, reposition
(center) the weight and turn the adjustment screw
counterclockwise 1/16 to 1/8 intervals until the
weight shuts the pump off. Proceed to Step 5.
4. The pump did not shut off or skipped (cycled on
and off). The pressure switch must be adjusted to
a positive shutoff with the 75 pound load. Return
the platform to floor level and reposition (center)
the weight. Using a 3/32" hex drive, turn the
adjustment screw counterclockwise 1/16 to 1/8
intervals until the weight shuts the pump off.
Note:
Press the OUT (Unfold) switch to return
the platform to floor level before each adjustment.
Press the IN (Fold) switch to test operation
following each adjustment. Proceed to Step 5.
5. Test the Fold function with an empty platform.
The platform should fold without any hesitation or
“skipping.” If it does hesitate, inspect and lubri-
cate the lift pivot points. Excessive friction at the
pivot points can cause hesitation when folding.
