SECTION 2 - PROCEDURES
3120743
– JLG Lift –
2-49
2.21 FREE WHEELING PROCEDURE.
Use the following procedures ONLY for emergency move-
ment to a suitable maintenance area. (See Figure 2-38.)
1.
Chock all wheels securely.
2.
Engage the mechanical release on both brakes by
loosening, completely reversing (towards drive
motor) and tightening the three nuts on each brake.
3.
Connect suitable equipment, remove chocks, and
move machine.
4.
After moving machine, position on a firm, level sur-
face.
5.
Chock wheels securely.
6.
Disengage the mechanical release on both drive
brakes by loosening, completely reversing (towards
torque hub) and tightening the three nuts on each
brake.
7.
Remove chocks from wheels as desired.
2.22 FOOTSWITCH ADJUSTMENT.
Adjust switch so that functions will operate when pedal is
at center of travel. If switch operates within last 1/4 inch
(6.35 mm) of travel, top or bottom, it should be adjusted.
2.23 P/Q CONTROLLER.
The PQ Controller converts manual input into proportional
electrical output signals for commanding proportional flow
control valves. The PQ Controller is a sealed unit and can
withstand hostile and rugged outdoor weather conditions.
The control handle enters the housing through a sealed
bearing, reducing the possibility of water entering the
housing.
The PQ Controller incorporates a mechanical safety lock
whereby the operator must make an additional motion to
unlock the control handle prior to operation. This feature
eliminates the possibility of the control being accidently
energized while in the neutral position. The controller also
incorporates a neutral-position-off switch. When the con-
trol handle is in its neutral position, a switch contact
opens, thus removing power from the electrical circuitry of
the controller. The control handle is spring loaded, and will
automatically return to the neutral-off position should the
operator accidently lose grip of the handle. this feature
gives the operator positive control of the machine at all
times, requiring the operator to hold the control handle
during the duration of the desired function.
Switch adjustment
Refer to manual 3120351.
Pulse Width Modulation (PWM) Fine tune
adjustment
Refer to manual 3120351.
Figure 2-41. Drive Brake Release.
Property of American Airlines