Urrea CP1040 Manual De Usuario página 18

CAUTION: The Torch handle is now ener-
gized. Be careful not touch anything else with
the Torch except the workpiece to be cut.
WARNING: Never look at the ignited arc
without the approved, arc shaded, eye protec-
tion in a full face shield. Permanent eye dam-
age or blindness can occur, also Skin burns can
occur. Never breathe arc fumes.
14. Bring the Electrode (4A) of the Torch close
to the staring point of the cut. The Working
Indicator Light will come on.
15. Slowly move the Torch at a slight angle
along the cutting line with the Torch tip trail-
ing. The air causes the molten metal to fall
away from the workpiece being cut. If proper
cutting is not achieved, adjust the Power Sup-
ply Controller to a higher level, and/or increase
air flow. To increase air flow, press the Power
Switch to the Off (O) position, then adjust the
air pressure at the Air Pressure Regulator. The
air will continue for a few seconds once the
trigger is released.
NOTE: If too much current is drawn from the
Plasma Cutter (i.e., short circuit),the Thermal
Switchman overload protector, will activate
and the red Thermal Overload Indicator Light
will light. The Plasma Cutter will turn off un-
til it cools down. To reset you must turn the
power OFF then back ON. Press the Trigger to
begin cutting again.
16. When finished cutting:
a. Release the Torch handle trigger and lift
the Torch handle from the workpiece,
b. Press the Power Switch to the Off (O) posi-
tion.
c. Set the Torch handle down on the metal
workbench,
d. Turn the air supply off,
e. Unplug the line cord from the electrical
outlet.
PLASMA CUTTING TECHNIQUE
Using a plasma cutter is a skill that requires
time and effort to do well. Practice striking and
maintaining an arc on scrap work pieces before
beginning work. This will help you gauge the
best settings for the plasma cutter for the ma-
terial at hand.
18
1. You can cut metal that will conduct electric-
ity up to approximately 1/2" thick mild steel or
equivalent. Very thin or very thick metals are
more difficult to cut cleanly.
2. Generally set the air pressure between 60
and 80 psi. Increased air pressure will increase
plasma speed and cutting pressure. Air pres-
sure and amperage should be adjusted in
tandem.
3. Generally start with a mid-range amperage
setting (32-33 amps) and adjust up or down
from there. Increased amperage will increase
cutting heat. This is needed with heavier and
harder metals. However, increased amperage
will reduce Duty Cycle time.
4. Move the cutting head more slowly for
thicker and harder metals, and more quickly
for thin or soft metals. Keep the cutting head
moving while cutting.
HOW DO PLASMA CUTTERS WORK?
Plasma cutters work by feeding an inert gas
(air) through an electric arc. The air is then
heated to an extremely high temperature
which converts the gas to plasma which cuts
the metal.
High temperature and pressure are required
to create a plasma. The electric arc provides
the temperature, and by exhausting the air
through a very small orifice, the pressure is
increased far beyond the 60-80 PSI operating
pressure of the air supply.
Plasma cutters work by sending a pressurized
gas through a small channel. In the center of
this channel, there is a negatively charged
electrode. When power is supplied to the
negative electrode, and the tip of the nozzle
contacts the work metal, the connection cre-
ates a circuit. When the nozzle is lifted away,
the arc will continue. As the inert gas passes
through the channel, the arc heats the gas
until it becomes ionized. This reaction creates
a stream of directed plasma, approximately
30,000°(16,649˚C) and moving at approximate-
ly 20,000 feet per second (6,096 m/sec),that
reduces metal to molten slag.
The plasma itself conducts electrical current.
The cycle of creating the arc is continuous as
long as power is supplied to the electrode and