Operation
Section
LX 31/41 Work Platform3-2
3.0
Emergency Lowering
Pulling out on the Emergency Lowering Knob will
mechanically open the Down Valve. This will allow oil
to flow out of the Lift Cylinder, through the Down
Orifice (regulating the descent speed), through the
Down Valve, through the Lift Valve, and out to the
Hydraulic Reservoir. The Down Alarm WILL NOT
SOUND when lowering the platform with the Emer-
gency Lowering Knob.
LEVELING THE PLATFORM
(Outrigger equipped machines only.)
With the Chassis / Platform switch on PLATFORM, and
the Platform completely lowered, selecting EXTEND or
RETRACT with any outrigger switch will energize the
Outrigger Extend / Retract Relays providing power to the
Outrigger Solenoid Valves. This will allow oil flow
through the Outrigger Orifice (limiting speed), through
the Outrigger Valve, over the Counterbalance Valve to
extend the Outrigger Cylinder. Return oil flows through
the Counterbalance Valve (opened by pilot pressure
from the extend side of the circuit), through the Outrig-
ger Valve, and back to the reservoir.
Once an Outrigger is extended, the Outrigger Limit
Switch opens breaking the ground circuit to the Drive
Relay (disabling drive). The Outrigger Pressure Switches
will close when all outriggers are taking load, completing
the ground circuit to the Up Relay (enabling lift). When
Outriggers are fully retracted, the Outrigger Limit
Switches will complete the ground circuit to the Pres-
sure Switch Override Relay, which will complete the
ground circuit to the Up Relay (enabling lift).
RAISING THE PLATFORM
From the Platform Controls
Selecting PLATFORM at the Chassis/Platform Switch,
selecting LIFT at the Drive/Lift Switch, and pushing the
Control Handle FORWARD will energize the Drive/Lift
Relay, the Cutout Relay (the Cutout Relay will only stay
energized if the Level Sensor is level within 2
o
), the Up
Relay (completing the circuit to the Up Solenoid Valve),
and the Proportional Valve. This will allow oil flow
through the Proportional Valve (regulating the speed to
a rate which is proportional to the angle of Control
Handle deflection), through the Lift Valve, through the
Down Valve, and to the Lift Cylinder (raising the Plat-
form).
Machines equipped with outriggers must have them
either fully retracted or extended and taking load (see
Leveling the Platform).
From the Chassis Controls
Selecting CHASSIS at the Chassis/Platform Switch,
pressing the Throttle Button, and pressing the Up
Button, will energize the Throttle Relay (increasing the
Engine R.P.M.), the Proportional Valve (regulating speed
through 10 ohm resistor), and the Lift Valve. This will
allow oil flow through the Proportional Valve (regulating
the speed to a fixed rate which is set by the 10 ohm
resistor), through the Lift Valve, through the Down
Valve, and to the Lift Cylinder (raising the Platform).
LOWERING THE PLATFORM
From the Platform Controls
Selecting PLATFORM at the Chassis/Platform Switch,
and pulling the Control Handle backward will energize
the Down Relay (completing the circuit to the Down
Solenoid Valve), and the Down Alarm Relay (completing
the circuit to the Down Alarm). This will sound the
down alarm, and allow oil to flow out of the Lift Cylin-
der, through the Down Orifice (regulating the descent
speed), through the Down Valve, through the Lift Valve,
and out to the Hydraulic Reservoir.
From the Chassis Controls
Selecting CHASSIS at the Chassis/Platform Switch, and
pressing the Down Button will energize the Down Relay
(completing the circuit to the Down Solenoid Valve),
and the Down Alarm Relay (completing the circuit to
the Down Alarm). This will sound the down alarm, and
allow oil to flow out of the Lift Cylinder, through the
Down Orifice (regulating the descent speed), through
the Down Valve, through the Lift Valve, and out to the
Hydraulic Reservoir.
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