OM2041 9/11 Safety - Section 20 Page 20-17 Precautions Before Welding or Performing Maintenance 6. Power cables and wiring harnesses must be protected from weld spatter and heat. 1. Open the access panel at the right front side of the control cabinet. Verify that the green link voltage light is illuminated and the DC bus voltage gauge reads 0.0 V. Notify qualified drive system maintenance personnel if the green link voltage light remains off longer than five minutes after engine shutdown. Always fasten the welding machine ground (-) lead to the piece being welded. The grounding clamp must be attached as near as possible to the weld area .
Avoid laying welding cables over or near the truck electrical harnesses. Welding voltage could be induced into the electrical harness and cause damage to components. 2. Locate the alternator cutoff switch access panel at the right front side of the control cabinet. Place the CUTOFF switch in the ON position. This will prevent the alternator from re- energizing and creating system voltage until the switch is returned to its former position. Before welding on the truck, disconnect the battery charging alternator lead wire and isolate the electronic control components. Also, disconnect the negative and positive battery cables of the truck.
Failure to do so may seriously damage the battery and electrical equipment. 3. Before doing any welding on the truck, always disconnect the battery charging alternator lead wire. 4. Do not weld on any drive system components! Consult your Komatsu service representative before attempting any welding procedures. Never allow welding current to pass through ball bearings, roller bearings, suspensions or hydraulic cylinders. 7. If the green link voltage light is off and the DC bus voltage gauge reads more than 0.0 V after following the precautions, a fault has occurred. 5. Power cables must be cleated in wood or other non-ferrous materials.
DO NOT repair cable cleats by encircling the power cables with metal clamps or hardware. Always inspect power cable insulation before servicing the cables and returning the truck to service. Discard cables with broken insulation. Leave all cabinet doors in place. Do not touch the retarding grid elements. Do not disconnect any power cables or use them as hand or foot holds. Notify your Komatsu service representative immediately. Only qualified personnel who are specifically trained for servicing the AC drive system should perform this service. 8. After welding or maintenance is complete, install all covers and close all access doors.
Place the alternator cutout switch and battery disconnect switches in their original positions. Reconnect all harnesses before starting the truck. NOTE: Leave the drive system in the “rest” mode until the truck is to be moved.