Nilfisk-Advance SC6000 36C Service Manual

Also see for SC6000 1050D: Instructions for use

Contents

Nilfisk-Advance SC6000 36C Service Manual Manual pdf 49 page image

49Service Manual – SC6000 20 - Wheel System, TractionDrive ControllerThe KSI relay provides logic power to the drive controller When the main machine controller is notenergizing the KSI relay, the drive controller has no power However, the drive controller has control of itsown power relay (K3) This provides separate high-current power output for the motor control The drivecontroller also monitors the E-stop switch and seat switch, so that either one can disable the drive outputOutput is disabled if either the seat switch or E-stop is open The drive controller also receives many of itsoperating parameters from the main machine controllerThe motor contains an electromechanical brake, that releases only when power is present The drivecontroller releases the brake when the wheel motor is commanded to turnE2 Main Control BoardE4 Wheel Drive ControllerK1 KSI RelayControlK3 Relay ControlPowerCAN Bus3Ø PWMTemp/PosFeedbackFoot PedalMain Battery PowerWheel MotorE-Stop SwitchBrakeThe drive motor is controlled from a Curtis 1232E drive controller, which is an AC induction motor controllerfor battery operated equipment The controller generates a square wave, 3-phase, pulse-width-modulatedoutput to the motor. The speed controller is designed specifically for DCmotors with remote commutation Pulse-width-modulation (PWM) is aform of motor speed control that alters the power to a motor by rapidlyturning the power on and off. The ratio (also called “duty cycle”) betweenthe On and Off states determines how much power the motor receivesThe shorter the “off-time” the closer to full power the motor will receive.This switching occurs so fast (15kHz for this controller) that the motorsimply sees it as a reduction in power (voltage) instead of the rapid on/offPWM is a standard motor control technique because it is easier to turnpower all the way on and all the way off, than it is to vary the magnitudeof the power Varying the magnitude would create a lot of heat thatwould need to be dissipated25% PWM Duty Cycle50% PWM Duty Cycle75% PWM Duty Cycle100% PWM Duty Cycle1-Cycle(15kHz)