JLG 120HX Service Manual - Manual (Page 70)

SECTION 2 - PROCEDURES
2-48 – JLG Lift – 3120819
2.23 PQ CONTROLLERS
NOTE: The following procedures are to be used as a begin-
ning basis for controller adjustment. After completing
the procedure, final adjustments are to be made
based on the machines function speed.
TRIM Adjustment (Prior to S/N 38697)
1. Perform the following checks with ignition power to
the platform, with the engine NOT running.
1. Install ammeter capable of measuring from zero to 2
amps in series with either valve coil B or D.
2. Position IGNITION/EMERGENCY STOP switch to
ON, but do not start engine.
3. Using a screwdriver, adjust the ramp trimpot coun-
terclockwise 25 turns or until the trimpot clicks.
4. Depress footswitch.
5. Operate controller until trailing edge of slide lock is
even with housing lock notch. Hold control handle in
that position.
6. Check the mA reading in the opposite direction.
7. Operate the controller until the trailing edge of the
slide lock is even with the housing lock notch. Hold
the control handle in that position. Check the mA
reading.
8. Verify step 7 and step 8 mA readings are within 0.50
mA of each other. If the readings are within toler-
ance, proceed to step 12.
9. If the readings in step 9 were not within tolerance,
Loosen the setscrew located in the gear on the
potentiometer shaft of the controller. Using a screw-
driver, adjust the potentiometer very slightly in either
direction. Tighten the setscrew on the gear and
recheck for the proper mA readings. Repeat this
step until the proper adjustment is obtained.
10. Place the creep toggle switch in the off position.
11. Using correct size common blade screwdriver,
adjust LO trimpot until ammeter indicates the proper
value as shown in Table 2-4, Function Speeds.
Clockwise rotation of trimpot adjust screw increases
ammeter; counterclockwise rotation decreases
ammeter reading.
12. Operate controller in the same direction as in step 6
to the full extent of its travel and hold handle in that
position.
Table 2-4. Function Speeds
Function
Function Speed
In Seconds
(Prior to S/N
38697)
In Seconds
(S/N 38697
to Present)
Telescope
Extend 132-170 80-100
Retract 140-175 75-100
Lift
Up 125-160 85-100
Down 108-132 75-100
Extend-A-Reach
Up 15-25 15-25
Down 15-25 15-25
Swing Speed
Full 360 160-200 160-200
Platform Rotation
Left 20-30 20-30
Right 20-30 20-30
Ground to 120’
257-330 165-200
From 120’ to Ground
248-307 150-200
Ground to 120’ to Ground
505-637 315-400
Drive Speed
46-56 @ 200ft. 46-56 @ 200ft.
Table 2-5. Platform Controller Settings (Prior to S/N
38697)
Function
Settings in mA
Lo Hi
Lift 300 500
Swing 300 500
Table 2-6. Platform Controller Settings (S/N 38697 to
Present)
Function
Settings in mA
Ramp
Turns
Lo Mid Hi
Lift 200 400 1100 6
Swing 200 400 1100 6
Drive 40 70 180 10
Flow Control 170 N/A 1000 N/A