Service And Maintenance; General; Safety And Workmanship; Oem Controller Electronics Information - Skyjack SJ 3215 Service Manual

Section 5 - Procedures

General

The following information is provided to assist you in
the use and application of servicing and maintenance
procedures contained in this chapter.

Safety and Workmanship

Your safety, and that of others, is the first consideration
when engaging in the maintenance of equipment.
Always be conscious of weight. Never attempt to move
heavy parts without the aid of a mechanical device. Do
not allow heavy objects to rest in an unstable position.
When raising a portion of the equipment, ensure that
adequate support is provided.
Platform
5.1-1

OEM Controller Electronics Information

Flow Control
Single coil or solenoid for single direction. The coil
has two connections; one is wired to the P .C. Board
(A) terminal and the other is wired to (-), or the
negative side of the supply voltage. Switches to control
directional valves may be provided on the controller.
Adjustment Procedures
Adjustments are made by turning a trimpot adjustment
screw. The trimpots are multi-turn, end-to-end devices.
It may be necessary to turn the adjustment screw
several turns to observe a change in output.
Clockwise (CW) adjustment of the trimpot increases
the output.
Counter-clockwise (CCW) adjustment of the trimpot
decreases the output.
Adjustments affect output current, voltage or percentage
of duty cycle to the coil. The minimum and maximum
output is preset at the factory. However, for optimum
performance, they must be adjusted while the
equipment is operating.
Although the following adjustments affect the current/
voltage or percentage of duty cycle, the best way
to adjust the function is to observe the response or
speed of the function. The following adjustments affect
function response, or speed. There may be some
interaction between adjustments, making it necessary
to repeat the adjustment in order to achieve the desired
response.
SJIII Series

Service and Maintenance

"Threshold" Adjustments
Adjust the initial current flow or duty cycle, affecting
the function response or speed when the handle is
first moved from the off position. Deflect the handle
slowly to the position where the controller first turns on.
Adjust the threshold trimpot screw to the point where
the controlled function just starts to move, then turn
the trimpot screw one, full turn in the counterclockwise
direction. This adjustment should be done first.
"Maxout" Adjustments
Adjust the full stroke current or duty cycle affecting the
maximum function response, or speed when the handle
is deflected to its full travel. Fully deflect the handle,
and adjust the maxout trimpot for maximum desired
function response or speed. To obtain proportional
resolution, it is important that the function starts to slow
down as soon as the handle is moved back from the
fully deflected position.
The ideal adjustment occurs when the function just
begins to move when the handle is deflected, and the
output increases until it reaches its maximum desired
response or speed at the end of handle travel.
SKYJACK, Page 3