Telwin SUPERIOR PLASMA 160 Manual Del Usuario página 8

5. INSTALLATION
ATTENTION! CARRY OUT ALL INSTALLATION AND
ELECTRICAL CONNECTION OPERATIONS WITH THE PLASMA
CUTTING MACHINE RIGOROUSLY SWITCHED OFF AND
DISCONNECTED FROM THE MAINS.
THE ELECTRICAL CONNECTIONS MUST ONLY BE CARRIED
OUT BY EXPERT OR QUALIFIED TECHNICIANS.
Assembling the clamp-return mass cable (Fig. G)
POSITIONING THE MACHINE
The machine must be installed in a place where there are no
obstructions to the cooling air input and output apertures; at the same
time, make sure that there is no possibility of conductive powder,
corrosive vapour or moisture etc. being sucked into the machine.
Allow at least 250 mm of free space all around the machine.
WARNING! Prevent the machine from tipping up or
shifting dangerously, by positioning it on a level surface that is
able to support its weight.
CONNECTION TO THE MAIN POWER SUPPLY
- Before making any electrical connection whatsoever, check the
power source rating plate to make sure that the mains voltage and
frequency correspond with those at the place where the machine is
to be installed.
- The power source must be connected only and exclusively to a
power supply system with a neutral conductor connected to earth.
- In order to guarantee protection against indirect contact use RCD's
of the following types:
- Type A (
).
- In order to satisfy the requirements of the EN 61000-3-11 (Flicker)
standard we recommend connecting the power source to interface
points of the main power supply that have an impedance of less
than Zmax = 0.2 ohm.
- The plasma cutting system does not fall within the requisites of
IEC/EN 61000-3-12 standard.
Should it be connected to a public mains system, it is the installer's
responsibility to verify that the plasma cutting system itself is
suitable for connecting to it (if necessary, consult the distribution
network company).
Plug and outlet
Connect the power supply cable to a standard (3P + T) plug of
appropriate capacity and prepare a power supply outlet fitted with
fuses or an automatic circuit-breaker; the corresponding earth
terminal should be connected to the (yellow-green) earth conductor
of the power supply. Table 1 (TAB.1) shows the recommended sizes
(in amps) of the delayed mains fuses, to be chosen according to the
maximum rated current output from the power source, and to the
rated power supply voltage.
ATTENTION! Failure to comply with the above rules
renders the safety system (class I) ineffective, with resulting
serious risks for people (e.g. electric shock) and for property
(e.g. fire).
CUTTING CIRCUIT CONNECTIONS
ATTENTION! BEFORE
FOLLOWING CONNECTIONS, MAKE SURE THE CURRENT
SOURCE IS OFF AND DISCONNECTED FROM THE MAINS.
Table 1 (TAB. 1) gives the recommended values for the return cable
(in mm
2 ) according to the maximum energy supplied by the machine.
Compressed air connections (Fig. H).
- Prepare a compressed air distribution line with a working pressure
and minimum capacity indicated in table 2 (TAB. 2).
- Pressure reducer connected as indicated (Fig. E).
IMPORTANT!
Do not exceed the maximum input pressure of 8 bar. Air containing
CARRYING OUT THE
large quantities of humidity or oil can cause excessive wear of
consumable parts or damage the torch. If in doubt concerning the
quality of the compressed air available, it is recommended to use an
air dryer to be installed downstream of the inlet filter. Use a flexible
hose to connect the compressed air line to the machine, using one
of the fittings supplied to be mounted on the air inlet filter at the back
of the machine.
Connecting the cutting current return cable.
Connect the cutting current return cable to the piece to be cut or the
metal support bench taking the following precautions:
- Check that a good electric contact is established especially when
cutting sheet metal with insulating, oxidised coatings etc.
- Connect the mass as close as possible to the cutting point.
- Do not use metal structures that are not part of the workpiece as a
cutting current return conductor; this can endanger safety and give
unsatisfactory cutting results.
- Do not connect the mass on the section of the piece to be removed.
Connecting the plasma cutting torch (Fig. F) (were available)
Insert the male end of the torch in the central connector on the front
panel of the machine, making sure the polarisation key is aligned.
Fully tighten the locking ring nut clockwise to guarantee there are no
leaks in the air and current flows.
In some models, the torch is supplied already connected to the
current source.
IMPORTANT!
Before commencing cutting operations, check the consumable parts
are assembled correctly, inspecting the torch head as indicated in the
"TORCH MAINTENANCE" chapter.
WARNING!
USING THE PLASMA CUTTING SYSTEM SAFELY.
Only the torch model as envisaged, coupled with the
corresponding power source as indicated in TAB. 2, are able to
guarantee effective protection by the safety system provided by
the manufacturer (interlocking system).
- DO NOT USE other makes of torch and related consumable
parts.
- DO NOT ATTEMPT TO COUPLE THE POWER SOURCE with
torches built for cutting or welding procedures that are not
contemplated in these instructions.
Failure to comply with these rules may cause serious hazards,
endangering the physical safety of the user and damaging the
apparatus.
6. PLASMA CUTTING: PROCESS DESCRIPTION
The plasma arc and plasma cutting application principle.
Plasma is a gas heated to an extremely high temperature and ionised
so that it becomes an electrical conductor. This cutting procedure
uses plasma to transfer the electric arc to the metal piece that is
melted by the heat and separated. The torch uses compressed air
supplied by a single source, both for plasma gas and for cooling and
protection gas.
Starting the pilot arc
The cycle is started by a pilot current that flows between the
electrode (polarity -) and the torch nozzle (polarity +) and the start
of the air flow.
Approaching the torch to the piece to be cut, connected to the current
source polarity (+), the pilot arc is transferred and creates a plasma
arc between the electrode (-) and the piece itself (cutting arc). The
pilot arc is excluded as soon as the cutting arc is established between
the electrode and the piece.
The factory setting stay time of the pilot arc is 2 seconds (4 seconds
in GOUGING mode); if the arc transfer to the piece is not effected
within this time, the cycle is automatically blocked, maintaining the
cooling air.
To start the cycle again, release the torch button and press it again.
Preliminary procedures.
Before commencing cutting operations, check the consumable parts
are assembled correctly, inspecting the torch head as indicated in the
"TORCH MAINTENANCE" paragraph.
- Turn on the current supply and set the cutting current (Fig. D-1)
according to the thickness and type of metal material to be cut.
TAB. 3 shows the cutting rate according to the thickness of
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