Nilfisk-Advance 56397010 Service Manual

FORM NO. 56043056 ConvertaMAX™ 20/26 / BA 550/650 - 39WHEEL DRIVE SYSTEMFRONTChainDrive WheelDrive Wheel MotorR1 Potentiometer(25,000 Ohms)R2 Potentiometer(5,000 Ohms)WHEEL DRIVE TROUBLESHOOTING GUIDEProblem Possible Cause• No forward or reverse wheel drive. See Electrical Troubleshooting Flowcharts A & B.• No wheel drive in one direction, Controller can’t change electrical polarity to wheel motor.loss of either forward or reverse. Replace the (A1) speed control.• Machine creeps (moves) in forward or • Check movement of the drive paddle spring centering devicereverse with only the key switch ON. (auto dead-man return to neutral components). Repair or replaceneeded parts.• The R2 drive pot is out of adjustment. Reset to neutral the 5000Ohm drive paddle potentiometer (*).• During normal machine transporting with the 5K The R1 (25,000 Ohm) speed limiting pot wiper is either opendrive paddle pot activated the operator also adjusts where the machine runs at minimum speed or the pot wiperthe control panel maximum speed limiting R1 pot and is shorted and runs at maximum speed. Replace the R1 pot (**).does not affect the desired maximum machine speedoutput.* See Potentiometer Installation and Adjustment instructions in this manual section and reset the (5K) pot to neutral.** See 25K Wheel Drive Speed Limit Potentiometer Testing instructions in this manual section.FIGURE 3revised 9/01