Scru S ste
C lin rical
Service Manual – SC8000
Scru rus
Motors
For the scrub brush motors to run:
The
Driver Box
must receive a signal from the
Drive Pedal Sensor R1
that the drive pedal has been moved
from the neutral position.
The
Driver Box
must provide a ground at pin
J2-7
to energize the
Scrub Brush
solenoid valve
S4
which
GLUHFWVWKHK\GUDXOLFÁXLGWRÁRZWKURXJKWKHVFUXEEUXVKPRWRUV
Scru i t
C lin er
For the scrub lift cylinder to actuate the scrub deck:
The
Scrub Cylinder Lock
solenoid valve
S6
PXVWRSHQWRDOORZRLOWRÁRZWRDQGIURPWKH
Scrub Lift Cylinder
.
The
Driver Box
must provide the appropriate ground signal from pin
J2-26
to the
Scrub Pressure
Proportional Down
valve
S5
, and the appropriate ground signal from pin
J2-24
to the
Scrub Pressure
Proportional Up
valve
S7
to provide the down scrub pressure selected by the Operator.
Note that the
Driver Box
ground signals to
S5
and
S7
are pulse width modulated (PWM) signals which
open the valves proportionally to produce the appropriate hydraulic pressures on both the piston and rod
ends of the
Scrub Lift Cylinder
. This combination of up and down forces on the lift cylinder, combined with
the weight of the cylindrical scrub deck, applies the correct amount of downward force on the scrub deck
to produce the desired scrub pressure.
Also note that the signals to the
S5
and
S7
valves allow the valves to “dither” (oscillate in a slight back-
and-forth motion at high frequency) to prevent the valves from sticking.
Once the scrub deck is retracted upward after scrubbing, the The
Scrub Cylinder Lock
solenoid valve
S6
FORVHVWRVKXWRIIWKHRLOÁRZIURPWKHVFUXEOLIWF\OLQGHUWRHQVXUHWKDWWKHGHFNUHPDLQVUHWUDFWHG
