Komatsu 960E-1 -, Shop Manual, Page: 41 / 51

00 Index and foreword CEN00002-05
23
Precautions for welding on the truck
NOTE: Before welding or repairing an AC drive truck,
notify a Komatsu service representative. Only
qualified personnel, specifically trained for servicing
the AC drive system, should perform this service.
If it is necessary to perform welding on the truck
without the field engineer present, the following
procedures and precautions must be followed to
ensure that the truck is safe for maintenance
personnel to work on and to reduce the chance for
damage to equipment.
• Before opening any cabinets or touching a
retarding grid element or a power cable, the
engine must be shutdown and any red drive
system warning lights must not be illuminated.
• Always disconnect the positive and negative
battery cables of the truck before doing any
welding on the unit. Failure to do so may
seriously damage the battery and electrical
equipment. Disconnect the battery charging
alternator lead wire and isolate the electronic
control components before making welding
repairs. (It is not necessary to disconnect or
remove any control circuit cards on electric drive
dump trucks or any of the AID circuit control
cards.)
• 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. Never allow welding current to
pass through ball bearings, roller bearings,
suspensions or hydraulic cylinders. Always avoid
laying welding cables over or near the vehicle
electrical harnesses. Welding voltage could be
induced into the electrical harness and possibly
cause damage to components.
• Drain, clean, and ventilate fuel tanks and
hydraulic tanks before making any welding
repairs on the tanks.
• Before welding on the truck, disconnect all
electrical harnesses from the modules and
controllers inside the auxiliary control cabinet
behind the operator cab.
• Do not weld on the rear of the control cabinet!
The metal panels on the back of the cabinet are
part of capacitors and cannot be heated.
• Do not weld on the retarding grid exhaust
louvers!
They are made of stainless steel. Some
power cable panels throughout the truck are also
made of aluminum or stainless steel. They must
be repaired with the same material or the power
cables may be damaged.
• 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.
• Power cables and wiring harnesses should be
protected from weld spatter and heat.
• 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.
• Always avoid laying welding cables over or near
the vehicle electrical harnesses. Welding voltage
could be induced into the electrical harness and
cause damage to components.
• Before doing any welding on the truck,
disconnect the battery charging alternator lead
wire and isolate electronic control components.
• Also, always disconnect the negative and positive
battery cables of the vehicle. Failure to do so may
seriously damage the battery and electrical
equipment.
• Never allow welding current to pass through ball
bearings, roller bearings, suspensions or
hydraulic cylinders.