Connection To The Mains; Maintenance - Telwin PLASMA 41 XT Bedienungsanleitung

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. H) (where applicable).
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.
ATTENTION!
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.

CONNECTION TO THE MAINS

- Before making any electrical connection, check the rating plate on
the source of current corresponds to the mains voltage and frequency
available in the installation location.
- The source of current must only be connected to a power supply
system with neutral conductor connected to earth.
- To guarantee protection against indirect contact, use the differential
switches type:
Type A ( ) for mono-phase machines.
- 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 is not within the requirements of standard
IEC/EN 61000-3-12.
If it is connected to a public power mains, the installation technician
or user is responsible for checking the plasma cutting system can be
connected (if necessary, consult the mains provider).
Plug and socket.
Connect a standard plug (3P + E) to the power supply cable with adequate
capacity and use a mains socket equipped with fuses or an automatic
switch; the specific earth lug must be connected to the earth conductor
(yellow-green) of the power supply line.
Table 1 (TAB. 1) provides the recommended values in amperes of the line
slow blow fuses chosen based on the maximum nominal current supplied
by the source of current, and at the power supply nominal 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).
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 by activation of the air
flow which opens the short circuit of these two elements.
Then, 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 maintenance time of the pilot arc set in the factory is 2sec (4 seconds
in GOUGING mode).
If the arc transfer to the piece is not carried out within this time, the cycle
is automatically blocked, except maintenance of the cooling air.
To start the cycle again, release the torch button and press it again.
Preliminary procedures.
Before starting the cutting operations, check correct assembly of the
consumable parts by inspecting the torch head, as indicated in the
"TORCH MAINTENANCE" paragraph.
- Turn on the current supply and set the cutting current (Fig. C1-1 and
C2-1) according to the thickness and type of metal material to be cut.
- Where planned, press the air button (Fig. C-2) to start the air flow.
- Adjust the air pressure to the pressure value required for the type of
torch being used (TAB. 2).
- Turn the knob: pull upwards to release and turn to adjust the pressure
to the value indicated in the TORCH TECHNICAL DATA.
- Read the required value on the pressure gauge and then press the knob
to lock the setting.
- Allow the air flow to end spontaneously to make it easier to remove any
condensate accumulated in the torch.
In the absence of the air button this adjustment phase should be
carried out by pressing and releasing the torch button to allow air flow.
Cutting operation (Fig. I).
- Keeping the torch perpendicular to the material to cut, bring the nozzle
of the torch in contact with the piece.
- Press the torch button, after approx. 1 second the pilot arc starts.
- If the distance is suitable, the pilot arc is immediately transferred to the
piece giving rise to the cutting arc.
- Move the torch on the surface of the piece along the ideal cutting line
at a regular pace.
- Adjust the cutting rate according to the thickness and selected current,
checking that the arc exiting the lower surface of the piece is inclined
by approx. 15° in relation to the vertical line, in the opposite direction
to the operating direction.
Perforation (Fig. L).
To perform this operation or start cutting from the piece centre, start
with the torch inclined at an angle and move it progressively to a vertical
position.
- This procedure prevents the arc or smelted particles returns from
ruining the nozzle hole which will rapidly compromise its performance.
- Perforation of pieces with a thickness of up to 25% of the maximum
foreseen for the range of use can be performed directly.
Grid cutting procedure (where applicable).
This function may be useful to cut perforated sheet metal or grids.
Use the "select mode" knob (Fig. C-2) to select the grid cutting mode.
On completing the cutting cycle, keeping the torch button pressed, the
pilot arc will restart automatically.
Only use this function when required to avoid unnecessary use of the
electrode and nozzle.
ATTENTION! In this mode you are advised to use standard
sized electrodes and nozzles. In particular conditions,
using elongated electrodes and nozzles could cause
interruption of the cutting arc.

7. MAINTENANCE

WARNING! BEFORE
OPERATIONS, MAKE SURE THAT THE PLASMA CUTTING
SYSTEM IS SWITCHED OFF AND DISCONNECTED FROM THE
MAIN POWER SUPPLY.
ROUTINE MAINTENANCE
ROUTINE MAINTENANCE CAN BE CARRIED OUT BY THE OPERATOR.
TORCH (Fig. M)
Check the wear level of the torch parts used by the plasma arc regularly,
depending on the level of use.
The replacement frequency of the consumables depends on various
factors: as indicated in the paragraph "MOST COMMON CUTTING
DEFECTS".
1 - Nozzle holder.
Unscrew it from the torch head by hand. Clean thoroughly or replace
it if damaged (burns, deformation or cracks). Check the condition of
the upper metal section (torch safety actuator).
2 - Nozzle / Hood.
Check the wear level of the plasma arc flow hole and the internal
and external surfaces. Replace the nozzle if the hole has widened
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CARRYING OUT MAINTENANCE