3.0 Plasma Cutting Components
3.1 Plasma Cutting Power Sources
The plasma arc cutting power source changes the relatively high voltage,
low amperage primary power into low voltage, high amperage secondary
power suitable for plasma cutting.
The size of the power source depends on the cutting amperage it is
expected to deliver. Cutting of heavy section materials requires more
amperage than does cutting of thinner sections.
3.2 Plasma Cutting Capacity
Rated Output (A)
Cutting thickness (mm)
Steel
Stainless Steel
Aluminium
40A Single phase
10
9
4
60A Three phase
20
18
6
80A Three phase
25
22
8
100A Three phase
32
25
12
160A Three phase
50
35
20
3.3 Air Supply
The supply of air to the cutting process plays an important role. The force
of the air is used to blow the molten material (created by the plasma arc)
away from the cut area thereby creating separation. Air pressure and
amperage are two variables that are changed when increasing the
cut thickness.
Compressed air from compressed air lines is often contaminated with
moisture and oil residue. Contaminants such as these shorten the life of
the consumable torch parts, it is therefore recommended that an inline
filter drying system is fitted to all air delivery lines.
When air is supplied from a portable air compressor it is important
to ensure that the compressor has adequate pressure and airflow
rate capacity.
Typical air supply requirements
Pressure
4.5–6 bar
Draw‑off rate
150–200 L/min
8
BOC Smoothcut Plasma 40 Operating manual
24799 Smoothcut Plasma 40 OP Manual CC D7.indd 8
16/04/2014 1:00 pm
