Nilfisk-Advance 56397010 Service Manual

38 - FORM NO. 56043056 ConvertaMAX™ 20/26 / BA 550/650WHEEL DRIVE SYSTEM-+ 123456R1R2A1F3P1B-B+P2BLKMWHT/YELRED/BLUM2+24VVIOREDS5F1S1RED BRN/BLKRED/BLKBRN/RED-24VVIOORNGRNYEL(T1) (T2)(T3)(T4)M1M2GENERAL FUNCTIONAL OVERVIEWA 1/2 horsepower permanent magnet 24V DC motor drives the ConvertaMAX™ models 20/26 & BA 550/650. See Figure 3. The motor outputis delivered to a single front mounted drive wheel driven by a chain. See Figure 1. The speed of the motor is regulated by a solid-state speedcontrol (A1), located in the rear handle electrical compartment. The potentiometer (R2), mounted in the drive paddle, regulates both machinedirection and variable speed demands. A second pot (R1) is mounted in the control panel and its knob can be adjusted to control the machinesmaximum transport speed.Drive Motor System FunctionSee Figure 1. With the key switch S1 closed the violet wire inputs 24V to the A1 speed controller to make it operational (power it up). The F3 (30Amp) circuit breaker supplies the (Pos.) 24V power input to the T1 or B+ controller terminal (Brn/Blk wire). The black wire from the battery Negativestandoff supplies the (Neg.) 24V power input to the T2 or B- controller terminal. Moving the 5K Ohm R2 speed pot off its centered balanced neutralsetting activates the operator input to the speed control. Forward or reverse movement of the drive paddle rotates the pot shaft and its variableresistance changes causing internal voltage input signal changes within the controller. These pot voltage related signals then energize the Fwdand Rev directional relays that selects the motor polarity and final voltage level outputs at the M1 & M2 terminals.FIGURE 1Electrical Diagram*For complete description of all callouts see Electrical System Wiring Diagram.-+ 123456WHTR1R2A1(Partial)VIOORNGRNYEL BRN*YELWHT*GRN*ORNGRNP1Key Switch25K Ohms5K OhmsFIGURE 2This drawing shows additional controller input circuit detail. The R1 pot is shown at the Max speed limiting setting and the R2 pot in neutral.*Handle wiring harness changed. Machines built after December 1, 2000 have different wire colors at R2 pot. Green wire changed to GRN/YEL,brown wire changed to BLK #2 (wire with the number 2 printed on it) and white wire changed to BLK #1.revised 7/02