Nilfisk-Advance BRX 700 Service Manual

Also see for 56314019: Instructions for use

Contents

28 - FORM NO. 56043089 / AquaRide ™ / BRX 700SCRUB BRUSH SYSTEMFUNCTIONAL OVERVIEW• Cylindrical Brush System OverviewSee Figure 6. The machines AquaRide SE and BRX 700 use two cylindrical brushes that counter rotate to sweep up light debris and scrub at thesame 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 OverviewOn all models the scrub deck platform is raised & lowered automatically by a vertically mounted electric lift actuator motor (M1). The operation ofthe machine’s scrub functions are activated when the operator selects (presses) either the scrub maintenance or restoration (mode) panel buttons.The scrub brush pressure ranges (light through heavy) are programmable allowing the operator the choice to vary the scrubbing effort (pressure)for numerous carpet cleaning requirements. Note: See the Main Control Board Special Program Options section in this manual for more detailedoperation 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 combined membrane switchdisplay panel and main control board E1. The major scrub system functions are…• Scrub Brush Motor Run FunctionTo turn On (energize) the K1 brush motor solenoid either the scrub pressure maintenance or restoration buttons (location E1 panel) must be pressedand the (foot activated) drive pedal moved off its neutral position triggering an output from the R1 directional throttle potentiometer. These two-operator functions deliver the required E1 control board and A1 speed control circuit inputs.Detailed Explanation of the scrub motor functionA closed E1 membrane panel switch input (either maintenance or restoration) enables the E1 microprocessor automatic functions for the brushlift, brush solenoid, solution solenoid and vacuum solenoid. The next step is the movement of the foot pedal for the needed R1 throttle output tothe A1 speed controller, which causes either FWD or REV motor action. At the moment of R1 throttle input the A1 controller closes an internal coildriver and outputs a POS. 36V signal from pin #6 (wire color Red/Blk) to the E1 J4-10 connection. This positive input signal causes the controllerto output a NEG. 36V signal from J2 pin #1 (wire Wht/Red) and completes the K1 negative solenoid coil pulling in the high current contactor makingthe brush motor(s) turn on (run). Note: The positive K1 control circuit voltage is supplied by the E1 board’s J2 pin #8 wire (Wht/Brn).• Scrub Brush Actuator Lift Motor FunctionThe control board outputs activate (raise and lower) the scrub-deck for installing, removing and controlling the scrub brushes’ selected pressurelimits (current load). The negative (-) brush motor wire is specially designed so that it has a known (specified) resistance value. As brush motorcurrent passes through the negative wire that is, in effect, a low value resistor, a small voltage drop is measured across it which is proportional tothe motor current. This current measurement shunt circuit is made up of two small diameter sense wires (J4-12 Yel/Vio & J4-8 Blk) and are theinputs used by the control board to calculate the exact current level of the scrub brush motor(s). Any temperature change to the large (Neg.) motorwire affects its resistance so the circuit temperature is sensed by a thermistor (*) built into the control board. This allows the controller to providea level of error correction for the temperature resistance changes. When the controller senses a current draw out of the desired range (selectedpressure limit) it automatically turns on the M1 actuator motor to raise or lower the scrub deck. This process is on-going in maintaining the operator’sselected scrub motor current load (setting #) to sustain the desired brush working pressure.• Low Voltage Cut-Out FunctionThe purpose of the low voltage cutout function is to help prolong battery life. The main control board E1 is programmed to monitor the machine’sbattery pack voltage to prevent over discharging of the batteries. The brush motors, brush lift actuator and solution solenoid valve will turn OFFautomatically and cease to function when the batteries are discharged to the selected cutout level. The cutout level is adjustable between twosettings. The standard battery type (wet cell) is 31.5 volts (1.75 volts per cell) and maintenance free battery (gel) is 33 volts (1.83 volts per cell).Note: See the Electrical System for instruction in selecting (setting) the two different thresholds.* Thermistor: A special semiconductor resistor whose resistance value varies with temperature.Note: See the “Know Your Machine” section in this manual for a complete explanation for all scrub system operational modes.