Weldclass CutForce CF-40p, Руководство по эксплуатации

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24 © Weldclass 2019 | E.&O.E.
10 GENERAL GUIDE TO PLASMA CUTTING
10.1 How does Plasma Cutting work?
Plasma technology works by ionising air such that it can conduct electricity. This ionized gas is used to
produce an intense arc capable of cutting any electrically conductive material (i.e. all metals).
Plasma cutting only requires electricity and compressed air supply.
In simpler terms, Plasma cutters use an electric arc to cut or gouge metal, similar to Oxy cutting.
10.2 Duty Cycle Rating
CutForce machines are fitted with thermal overload protection which means the machine will cut out when
it reaches a certain temperature, to prevent damage to components. The machine will then re-start when
it returns to a safe temperature.
Duty cycle is a measure of the percentage of time a machine will operate within a certain time period at a
given amperage. For example a duty cycle of 40A @ 30% means that a machine will operate at 40A for 3
minutes in a 10 minute time period. The machine will have to rest for the remaining 7 minutes to enable it
to cool down.
The international standard for duty cycle rating is based on an ambient air temperature of 40°C with 50%
humidity, over a 10 minute period. In an environment with temperatures exceeding 40°C, the duty cycle
will be less than stated. In ambient temperature less than 40°C, duty cycle performance will be higher. There
are numerous other factors that can influence actual duty cycle performance.
10.3 Pilot Arc System
This machine uses a pilot arc system to establish the main cutting arc.
A pilot arc system is a circuit where the return is back through the torch head and cable. This means it can
create a small arc with some cutting power without making any electrical connection with the main
machine earth. This is especially useful for starting cuts on material that does not have a good initial earth
connection, such as paint, rust, scale.
Once the pilot arc is established and power is flowing back through the main earth, the pilot arc is switched
off and the main arc started. Please note the pilot arc circuit is only designed to operate for short periods
of time as an auxiliary starting system, so it has a safety protection that only allows the pilot arc to run for
short periods at a time.
In addition to this, this machine has a pilot arc controller system. If the main arc cuts out and the torch
remains to be triggered, the pilot arc will reignite. This is useful for cutting discontinuous workpieces like
mesh or grids.