Page 41
Systems Descriptions
Hydraulic Platform Sensor
Pressure Switch: L915 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 hydrau-
lic pump. This switch is acti-
vated 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).
pressing the DOWN switch then
energizes this solenoid/valve.
The manifold Unfold solenoid/
valve is de-energized, which
routes the hydraulic fluid through
the manifold internal pressure
compensator valve before
allowing it to return to the reser-
voir from the cylinders, thus
allowing gravity to lower the
platform at a reduced rate. The
manifold internal pressure
compensator valve allows a
limited rate of hydraulic fluid flow
dependent upon platform load.
Releasing the DOWN switch
de-energizes the solenoid/valve
allowing it to close, stopping
the flow from the cylinders to
reservoir. This stops and holds
the platform at the current
position.
If the Bridging microswitch has
been deactivated while the Down
switch is being pressed, only the
Down solenoid/valve remains
Hydraulic
Pressure Switch
3/32" Hex Drive
Adjustment Screw
Improper hydraulic
pressure switch
adjustment may
result in serious
bodily injury and/or
property damage.
W
A
RNING
K
energized. This allows the
hydraulic fluid to flow only from the
roll stop cylinder to the reservoir
once the roll stop latch releases
the roll stop (allowing the roll stop
to deploy).
Troubleshooting: A problem with
this solenoid/valve can be electri-
cal or hydraulic. Follow the
Quick-Check troubleshooting
procedure detailed the Solenoid/
Hydraulic Valve section on page
35 when troubleshooting.
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 plat-
form 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
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