7. Restriction caused by components: Correct and make adjustments to wheel brakes and parking brakes that drag. Make changes to tires with less restriction. Check and correct wheel bearing torques. Problem 7: Lift truck moves faster in one direction than the other direction with the same amount of accelerator pedal movement in Bypass mode (speed). Problem 5: Low resistance to ground [battery polarity either positive (+) or negative (-) or a medium voltage is in direct contact with truck frame (body) or drive motor body]. Probable Cause: 1. Motor brushes not located in the correct electrical position (brush neutral settings):
If the holes in the brush holder are not extended, make them longer so that brush holder can have a little rotation. When the holder is in the correct position, lift truck speed will be the same in both directions. Probable Cause: 1. Dirty battery, electrolyte on top of cells and is in contact with the frame. Current flows through battery box, which places a voltage on the truck frame: Clean the battery with baking soda and water solution. 2. One directional contactor worn more than the other or loose connection on one contactor: Check contactor for wear and tighten any loose connections. 2. Battery or control panel wire connections in contact with truck frame:
Make a continuity test and move the wire from contact. Remove wires in sequence until the fault is cleared. The fault will be in the wire last disconnected. Problem 8: Lift truck will not get to top speed. Probable Cause: 1. Battery not fully charged or battery has bad cells: Charge the battery. Check for bad cells. Replace battery if necessary. 3. Dirty motor: Remove metallic or carbon dust with air pressure. 2. A fault either in the drive motor, control panel or drive train: Check lift truck speed in both directions. If the MicroController panel needs tuned up, make adjustments as shown in the respective MicroController System Operation module.
If the drive motor is at fault, make the tests of the motor components in Testing And Adjusting. 4. Wet motor: To dry the motor, heat it to 90ЎC (194ЎF). Problem: 6. Commutator surface has groove or extra wear. Problem 9: Lift truck does not have enough power to position itself under a load. Lift truck does not have enough power on ramps or towing trailers. Probable Cause: 1. Brushes are worn too low, brush wires caused arcing on the commutator: Replace the brushes. See Brush Inspection in Testing And Adjusting and the method to make the Brush Lift Estimate in Testing And Adjusting. Probable Cause: 1. Current limit (C/L) set too low:
Set current limit (C/L) to specification in the MicroController System Operation module. 2. Dirty motor; and possibly salt water got inside: Disassemble motor, remove the debris with air pressure. If necessary, dry the motor with heat to 90ЎC (194ЎF) 3. Grades of brushes mixed: Make sure all the brushes are of DAEWOO standards. Do not use other brands of brushes. Power Train Testing And Adjusting 12