20
- FORM NO. 56043071 CMAX
™
28/34ST / I-MAX
™
28/32C, BA 750/850ST, BA 750C
SCRUB BRUSH SYSTEM
FUNCTIONAL OVERVIEW
• Disc Brush System Overview
See Figure 2. The machine models CMAX 28ST, CMAX 34ST, BA 750ST & BA 850ST (model #’s 56396010, 56397403, 56396011 & 56396012)
use the disc type scrub system.
• Cylindrical Brush System Overview
See Figure 4. The machine models I-MAX 28C, I-MAX 32C & BA 750C (model #’s 56397400, 56397401 & 56397402) use two cylindrical brushes
that counter rotate to sweep up light debris and scrub at the same time. Each scrub brush is powered on opposing ends by 3/4 HP permanent
magnet motors attached to separate poly-V belt/pulley drives.
• General Brush Overview
On all models the scrub deck platform is raised & lowered automatically by a vertically mounted electric lift actuator motor. The operation of the
machine’s scrub functions are activated when the operator selects (presses) the scrub (mode) panel buttons. The scrub pad or brush pressure
ranges (1-9) are selectable allowing the operator the choice to vary the scrubbing effort (pressure) while operating the machine. Note: See the
Main Control Board Special Program Options
section in this manual for more detailed operation and instructions to change scrub pressure settings.
See Figure 1. The machine’s main scrub system input and output operating functions are regulated (managed) by the display panel and combined
main control board A1. The major scrub system functions are…
• Scrub Brush Motor Run Function
Control Circuit Overview Scrub Brush Motor
+(Positive) Circuit input starts with:
•
A closed S3 key switch supplies the needed positive voltage to the K1 brush solenoid coil and the A1 control board #1 terminal (Brn wires).
Note: The A1 control board scrub-on/pressure increase button must also be depressed (enabled). This operator command lowers the brush
deck.
-(Negative) Circuit input starts with:
•
A battery negative ground input at the A1 control board terminal #4 and at the A2 speed controller terminal B- (T2).
•
A negative voltage output from the A2 speed controller’s P1 (pin #1) to the A1 control boards yellow wire (#3 terminal). Note: The A2 speed
control auxiliary output (pin #1) occurs whenever the R1 directional/throttle pot is moved off its neutral setting. This operator command
happens when the drive paddle is pushed or pulled to run the wheel drive motor in Forward or Reverse.
•
A negative voltage output from the A1 board’s terminal #5 Vio/Blk wire completes the K1 solenoid coil circuit (Pos. & Neg.) and pulls in the
load contact making the brush motors run.
• Scrub Brush Actuator Lift Motor Function
The A1 control board outputs (terminals 11 & 12) activate (raise and lower) the scrub-deck for installing, removing and controlling the scrub brushes’
selected current load. The large BLK negative (-) scrub brush motor wire is specially designed so that it has a known (specified) resistance value.
As brush motor current passes through the negative wire that is, in effect, a low value resistor, a small voltage drop is developed across it which
is proportional to the motor current. This voltage change is inputted to the A1 control board at terminal pins 8 and 2 (sense wires WHT/GRA &
GRA/BLK). Any surrounding temperature change in this large Neg. motor wire affects its resistance so the temperature is sensed by a thermistor
(*) built into the control board A1. This allows the controller to provide error correction for the temperature resistance changes. When the controller
senses a current draw out of the desired range it automatically turns on the M5 actuator motor to raise or lower the scrub deck. This process is
on going in maintaining the operator’s selected scrub motor current load setting to sustain the desired brush working pressure.
• Low Voltage Cut-Out Function
The purpose of the special low battery voltage cutout function is to help prolong battery life. The scrub deck will be raised and the brush motors
and solution solenoid valve will turn OFF automatically and cease to function when the batteries discharge to the selected cutout level. The cutout
level is adjustable between two settings. The standard setting (wet cell/lead acid) is 1.72 volts per cell and alternate setting (gel/maintenance free)
is 1.81 volts per cell. Note: See the battery system section for instructions for selecting (setting) the two different thresholds.
SPECIAL SCRUB SYSTEM FUNCTIONS
• Optional Scrub Brush Removal Function (Disc only)
For removal of the scrub brushes automatically, the scrub deck must be in the up position and the drive system in neutral. To remove the scrub
brushes simply depress the control panel scrub-off/pressure decrease button
(H)
for 1 second. The A1 control board will momentarily run the brush
motor and then stop it quickly, where the brush inertia causes the brush to easily spin itself off of the scrub brush motor drive cap.
• Control and Load circuit detail.
-
A closed S3 key switch supplies the needed positive circuit inputs (Brn wire) to the K1 brush solenoid coil, K3 brush remove solenoid coil
and A1 control board.
Содержание BA 750/850ST
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