Selco SP 70 Instrucciones De Uso página 19

2.2 Using the torch
Switch on the system, ensuring the LED is working correctly.
If torch components are missing or have been assembled incor-
rectly, or the compressed air pressure is too low, or entirely lack-
ing, LEDs turn on respectively to display the fault. The generator
is shut down until the fault is removed.
"Consult the section "Commissioning" of power source's instruc-
tion manual".
2.2.1 Inclination and speed of the torch during cutting
- Grip the torch and lift the protection lever (1).
- Press for a moment the torch button (2) so as to generate the
pilot arc; release the control, checking that machine is cor-
rectly operating on the display panel. It is suggested to switch
off the pilot arc in order to prevent wear on the electrode
and the nozzle. If pilot arc is triggered without perfoming any
cutting action, the power source control unit will switch off it
after 6 seconds to prevent damage to the torch.
Position the torch near the piece and begin cutting,
moving forward steadily.
The torch is generally held perpendicular to the workpiece
during all the cutting phases; obviously, whenever it is required
to carry out chamfering or inclined cutting, the torch must be
tilted to a suitable inclination.
The speed must be adjusted so that the outflow of the arc
below the workpiece is perpendicular (5-10 degrees of slope
are acceptable).
A slow speed start is advisable to prevent spray
of material which could damage the nozzle.
2.2.2 Puncturing
In some cases it is necessary to puncture a hole in the material
using plasma cutting. In this way, the wear on the parts which
are subject to deterioration will be increased, and it becomes
very important to try to work to avoid the return of spray, which
can be dangerous, especially with sheet metal over 5 mm. thick.
We suggest starting with the torch inclined side-
ways, so as to point the spray outside the cutting
area, avoidin g damage and overheating of the
torch body.
Immediately remove any material accumulated
on the nozzle or on the ceramic hood.
Caution: plasma cutting is a process with a high
thermal element, which takes both the piece to
be cut and the end parts of the torch to extreme-
ly high temperatures.
2.2.3 Circular cutting
For the preparation of flanges and opening holes, it is possible
to use a pair of compasses, equipped with rotating heads and
movement on wheels.
Compass kit (73.04.010)
Bevel tool (73.04.011)
2.2.4 Practical advice
We advise igniting the pilot arc away from the workpiece, and
then moving near until the cutting arc is struck; striking a cutting
arc repeatedly and directly by contact with the workpiece cre-
ates an increase in temperature of the torch body.
Avoid turning off the generator before the end of the post-cut
cooling flow, to avoid overheating of the components of the
torch.
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