Elliott Traffic Safety Service L60, Руководство оператора

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PQ Controller Adjustment
PQ Controller adjustment – Hi Reach Cranes
Correct adjustment of the PQ controllers on Elliott cranes is crucial to the smooth operation of the boom.
Elliott uses a dual range, dual coil controller. The following procedure can be followed for adjusting the
PQ electronic controllers:
1)
Verify that the pilot pressure is correct. The pilot pressure on a standard Elliott Hi Reach with
Parker /Apitech valve should be set at 215 – 220 psi. The pilot pressure test port is located on the
inlet section 90 degrees from the Pressure Reducing Valve. See below:
2) There are four trim pots located on the circuit board on each individual PQ controller. The
following procedure can be used when adjusting these trim pots should they be mis-adjusted or if
a controller is replaced:
LO – This trim pot should be adjusted first so that the appropriate amount of dead band is set in
the joystick or the amount that you have to move the joystick before you get function
engagement. Clockwise will turn up the decrease the joystick dead band. Turning it
counterclockwise will decrease the joystick dead band. Joystick controller dead band should be
set to operator’s preference. (NOTE: THIS ACTS AS THE THREASHOLD)
HI A&B – You should adjust this trim pot next. This is the maximum PWM signal out of
controller outputs “A” and “B” that is applied to the pulsar coils on the control valve. The “HI”
trim pots should be adjusted so that the control valve spool reaches full stroke at the same time
the joystick controller reaches full stroke. When adjusting controllers from the platform, a helper
may need to be utilized to watch the valve spool while the other adjusts the controller. Large
adjustments to the “HI” trim pots may affect the setting of the “LO” and visa versa.
MID – This trim pot should be adjusted after the “LO” and HI Range adjustments are made. The
trim pot should be adjusted so that there is a noticeable difference in function speed when you
select “low range” on the control panel and the joystick is at its full stroke. The joystick is
normally in low range and is shifted into high range when 12 VDC is applied to the “HI ENA”
terminal on the bottom of the joystick. (NOTE: THIS ACTS AS THE LOW RANGE)
RAMP
– This trim pot is an operator’s preference adjustment also. The more you turn the ramp
function up (clockwise) the less sensitive the joystick becomes. If the ramp is turned too high, a
noticeable delay in function engagement may be experienced upon activation of the joystick.