20 - FORM NO. 56043056 ConvertaMAX™ 20/26 / BA 550/650
SCRUB BRUSH SYSTEM
-
+
1
2
3
4
5
6
5
12
4
3
10
6
1
11
9
8
7
2
-
+
S6
D2
L1
R1
R2
S2
K1
F2
A2
Battery Switch
LIQ
.
GEL
.
A1
F3
P1
B-
B+
P2
+24V
-24V
S1
M
M
M3
M4
S3
BLK
VIO/BLK
#10
#14
BLK
#12
#16
BRN
ORN/BLK
WHT/RED
#8
BRN/WHT
GRA
VIO
GENERAL BRUSH SYSTEM FUNCTIONAL OVERVIEW
The ConvertaMAX™ 20 / BA 550 models use (1) scrub brush (20 inch Dia.) driven by a single 1HP 24VDC-combination motor/gear unit. The
ConvertaMAX™ 26 / BA 650 models use (2) scrub brushes (two 13 inch Dia.) driven by two 3/4HP 24VDC combination motor/gear units. The
scrub deck is raised and lowered manually by a rear mounted foot pedal.
Control Module Scrub System Functions
The ConvertaMAX™ 20/26 / BA 550/650 scrubbers have an electronic timer module (A2) that controls the activation of the scrub brush motors,
special scrub brush removal feature and a low voltage cutout function.
Scrub Brush Removal Function
For removal of the scrub brush(es) automatically the scrub deck must be in the up position and the drive system in neutral. To remove the scrub
brush(es) simply depress the control panel remove switch (S3). The timer module will momentarily run the brush motor and then stop it quickly,
where the brush inertia causes the brush to easily spin it’s self off of the scrub brush motor drive cap.
Low Voltage Cut-Out Function
The purpose of the special low battery voltage cutout function is to help prolong battery life. The brush motor(s) and solution solenoid valve will
turn off automatically and cease to function when the batteries discharge to 1.75 volts per cell or 1.83 volts per cell on alternate setting. Note: See
the battery system section for instructions for selecting (setting) the two different thresholds (wet cell, lead acid or gel, maintenance free). Special
Service Note: On all the 24V and 36V machines a minimum recharge voltage of 2.09 volts per cell must be reached to allow the scrub brush and
solution systems (to reset) function again. A 24V-battery pack must increase to a 25.1-volt minimum and a 36V battery pack to 37.6 volts.
Scrub Brush Motor Function
See Figure 1. To turn ON (energize) the K1 brush motor solenoid the operator must lower the brush deck to close the S6 brush switch and move
the drive paddle (Fwd or Rev) to activate the wheel drive.
These two operator functions described above deliver the required control circuit inputs, one positive and two negative, to start and stop the scrub
brush motor(s). The Pos. control circuit-input starts with the S1 key switch closed and a Pos. voltage input to the pin 11 on the A2 timer module.
The pin #11 is connected directly to pin #3 inside the module. The BRN wire from pin #3 sends the required Pos. control circuit input to the K1
coil terminal. One of the two Neg. circuit inputs is triggered when the machine is put in motion. The A1 speed control’s P1 connection sends a
Neg. input signal to the timer module pin #4. The second Neg. input is initiated when the S6 brush switch is closed sending a Neg. voltage signal
to the timer pin #9. With the two Neg. inputs completed the timer circuit closes an internal relay that sends from pin #2 (ORG/BLK wire) the needed
Neg. control circuit voltage to the K1 coil terminal. This then completes the K1 coil circuit (Pos. & Neg.) and pulls in the load contact making the
brush motor(s) run.
Electrical Diagram
*For complete description of all callouts see Electrical System
Wiring Diagram
.
FIGURE 1
revised 7/02
