Doosan DX700LC Operation And Maintenance Manual page 44

Welding Repairs
When you connect or disconnect connectors between ECU
and Engine or connector between ECU and the machine,
always disconnect the source power to protect damage of
the ECU.
If you don't observe this procedure, the ECU would be
damaged or the engine would operate abnormally.
When carrying out welding repairs, carry out the welding in a
properly equipped place. The welding should be performed by a
qualified worker. During welding operations, there is the danger
of, generation of gas, fire, or electric shock, so never let an
unqualified worker do welding.
The qualified welder must do the following;
• To prevent explosion of the battery, disconnect the
battery terminals and remove batteries.
• To prevent generation of gas, remove the paint from
the location of the weld.
• If hydraulic equipment, piping or places close to them
are heated, a flammable gas or mist will be generated
and there is danger of it catching fire. To avoid this,
never subject these places to heat.
• Do not weld on pipes or on tubes that contain
flammable fluids. Do not flame cut on pipes or on
tubes that contain flammable fluids. Before you weld
on pipes or on tubes or before you flame cut on pipes
or on tubes, clean the pipes or tubes thoroughly with
a nonflammable solvent.
• If heat is applied directly to rubber hoses or piping
under pressure, they may suddenly break so cover
them with a fireproof covering.
• Wear protective clothing.
• Make sure there is good ventilation.
• Remove all flammable objects and provide a fire
extinguisher.
Safety
1-38
CAUTION
OP001120