Xcel-Arc VIPER CUT 30Mk II, Operating Manual

Page: 17 / 24

Electrode condition
A fixed gap is established between the electrode and the inside of the cutting tip — electrons arc across the
gap, ionizing and superheating the air creating the plasma stream. The electrode contains an insert at the end
made of a highly conductive material called hafnium. This insert erodes with use and develops a pit at the end
of the electrode when the pit becomes too much poor-quality cuts will result and necessitate replacement of
the electrode.
Air pressure and volume
Air pressure, flow rate and air quality are critical to quality plasma cutting and consumable life span. The
required air pressure and volume can vary from model to model, and the manufacturer will provide the specs.
The VIPER CUT 30MkII air pressure must be adjusted and set to 0.5MPA (75psi) and requires a flow rate of 190
L/min. The volume capacity of your compressor is important. If you have a small compressor with precisely the
same L/min rating as the plasma, then the compressor will run continuously when you are plasma cutting. A
compressor with a L/min rating slightly higher than the plasma would be more than adequate.
If you are doing a lot of cutting, cutting thick plate (same air consumption but slower cut speeds = longer cut
time), then choose a compressor at 1.5 to 2 times the plasma system requirement.
Air quality
Good air quality is essential to quality plasma cutting and consumable life span.
Compressors take in air at atmospheric pressure and increase the pressure and store it in a tank. Humidity in
the air is condensed in the tank and the airlines producing water, more so in humid environments. Moisture
that forms in airlines tends to condense into larger drops when the air pressure decreases as it is entering the
plasma torch. When these droplets enter into the high temperatures (as much as 11,000°C) in the plenum of
the torch, they immediately break down into oxygen and hydrogen, which alters the regular chemical content
of the air in the torch. These elements will then dramatically change the plasma arc which causes the torch
consumable parts to wear very quickly, alters the shape of the nozzle orifice, dramatically affecting cut quality
in terms of edge squareness, dross formation, and edge smoothness.
Minimising the moisture in the air supply is absolutely critical to quality plasma cuts and longevity of
consumable parts. As a minimum be sure to drain the receiver (tank) on the air compressor at least daily.
Most air plasma systems from reputable manufacturers have an onboard particulate filter and or a coalescing
filter with an auto drain that will remove some moisture from the air supply. For home workshop and light
industrial users, the onboard air filter is adequate. Most situations, however, will require additional filtration
to prevent moisture from affecting the quality of the plasma cutter and in most cases, it is recommended to
install a submicronic particulate filter that is designed to trap water through absorption. This style of filter has
a replaceable filter cartridge that absorbs water and must be changed after it is near saturation; it should be
installed close as possible to the air intake of the plasma cutter.
Technique Tips
• It is easier to pull the torch through the cut than to push it.
• To cut thin material, reduce the amperage until you get the best quality cut.
• Use the correct size tip orifice for the amperage being used.
• For straight cuts use a straight edge or cutting buggy as a guide. For circles, use a template or circle cutting
attachment.
• Check that the front end consumable parts of the plasma cutting torch are in good condition.
Plasma Cutter Air Filter
AT1000 Plasma Air Filter Complete with Filter Cartridge
AT50505 Spare Filter Cartridge
Most situations, however, will require additional filtration to prevent moisture from
affecting the quality of the plasma cutter and in most cases, it is recommended to install a
submicronic particulate filter that is designed to trap water through absorption.
PLASMA CUTTING TIPS & TECHNIQUES
17