Würth MIG 180-5S Mode D'emploi Original page 31

ground cable to "-". Secure leads tight with fasteners.
(see fig. D (b) on page 8)
6.2. The gas hose, regulator and gas cylin-
der connection
Attach one end of the gas hose to the gas solenoid
valve (gas inlet) located on the back panel of the
welder. Attach the other end to the gas regulator
which is attached to the shielding gas cylinder.
a. Cylinder valve: Controls gas tank flow
b. Cylinder pressure gauge
c. Gas flow gauge, set at 570 lit./min
d. Adjustment knob (controls gas pressure)
e. Regulator
f. Gas hose
g. Gas cylinder (tank)
(see fig. E on page 8)
NOTE:
Slowly open the cylinder valve by turning it counterclock-
wise until the cylinder pressure gauge registers pres-
sure increase on the first gauge of the regulator. Turn
the adjustment knob clockwise (to the right) slowly to
increase gas flow to 570 lit./min. To reduce the gas flow
turn the adjustment counterclockwise (to the left). The gas
inlet valve is located on the back panel of the welder and
activated by the trigger on the torch. Gas flow should
be heard when the trigger is activated. No gas flow will
result in a harsh arc with excessive spatter, and smooth
weld bead will be difficult to obtain. Avoid unnecessary
gas loss by closing the tank valve when finished welding.
6.3 Gas selection
Different materials require different shielding gas
when MIG welding; refer to the set up chart pro-
vided inside the wire feed compartment.
Mild steel: Use 75% Argon and 25% CO
reduced spatter and reduced penetration for thinner
materials. Do NOT USE Argon gas concentrations
higher than 75% on steel. The result will be extremely
poor penetration, porosity, and brittleness of weld.
Mild steel: use 100% CO
but increased spatter.
Stainless steel: use gas mixture consisting of
Helium, Argon and CO
Aluminium or bronze: use 100% Argon gas.
Before use
WARNING!
High voltage danger from power source!
Consult a qualified electrician for proper installa-
tion of needed socket. This welder must be grounded
while in use to protect the operator from electric
shock. If you are not sure that your outlet is properly
for
2
for deeper penetration
2
gases.
2
grounded, have it checked by a qualified electri-
cian. Do not remove grounding prong or alter the
plug in any way. Do not use any adapters between
the welder's power cord and the power source
socket. Make sure the POWER switch is in OFF posi-
tion when connecting your welder's power cord to
a properly grounded 220/230VAC, 50/60Hz, 20
amp, single phase mains supply.
THE MIG WELDING OPERATION
1. Main controls
Power switch – The power switch supplies elec-
trical current to the welder. Whenever the power
switch is in the ON position, the welding circuit is
activated. ALWAYS turn the power switch to the OFF
position and unplug the welder before performing
any maintenance.
Voltage selector – The voltage selector controls
the welding heat. This unit has infinite voltage con-
trol. Refer to the label inside the welder side door for
recommended voltage selector settings required for
your welding job.
Wire speed control – The wire speed control
adjusts the speed at which the wire is fed out of the
welding torch. The wire speed needs to be closely
matched (tuned-in) to the rate at which it is being
melted off. Some of the few things that affect wire
speed selection are the type and wire diameter
being used, the heat setting selected, and the weld-
ing position to be used.
Note: The wire will feed faster without welding arc
established. When an arc is being drawn, the wire
speed will slow down.
2. Holding the torch
The best way to hold the welding torch is the way
that feels most comfortable to you. While practicing
to use your new welder, experiment holding the torch
in different positions until you find the one that seems
to work best for you.
3. Positioning the torch onto the workpiece
There are two angles of the torch nozzle in relation to
the workpiece that must be considered when welding.
3.1. Angle A can be varied, but in most cases the
optimum angle will be 60 degrees, the point at
which the torch handle is parallel to the work piece.
If angle A is increased, penetration will increase. As
angle A is decreased, the penetration is decreased
as well.
(see fig. F (a) on page 8)
3.2. Angle B can be varied for two reasons: to
improve the ability to see the arc in relation to the
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