Telwin 54 XT Manual De Instrucciones página 9

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
compared to the original diameter or is deformed. If the surfaces are
particularly oxidised, clean them with very fine sandpaper (FIG. N).
3 - Air distributor ring / diffuser.
Check there are no burns or cracks and that the airflow holes are not
blocked. Replace immediately if damaged.
4 - Electrode.
Replace the electrode when the depth of the crater that forms on the
emission surface reaches about 1.5 mm (FIG. O).
5 - Torch body, handgrip and cable.
Normally these components do not require any particular
maintenance except periodic inspection and thorough cleaning
without using solvents of any nature. If the insulation is damaged
showing cracks or burns or the electric conductors are loose, the
torch can no longer be used due to lack of conformity with the
required safety conditions.
In this case, repairs (extraordinary maintenance) can not be
performed on-site, as they must be performed by an authorised
service centre capable of conducting the special tests after the repair.
To maintain the torch in good working condition, some fundamental
precautions must be taken:
- Do not bring the torch or cable in contact with hot or scorching
parts.
- Do not apply excessive strain on the cable.
- Do not lay the cable on sharp corners, points or abrasive surfaces.
- Wind the cable into regular coils if it is longer than required.
- Do not allow any vehicle to drive over the cable and do not tread
on it.
WARNING! Before carrying out any work on the torch
leave it to cool for at least the complete "post air" time
- Except in special cases, we recommend changing the electrode
and nozzle at the same time.
- Assemble the torch components in the correct order (the reverse
of the order for dismantling).
- Make sure that the distributor ring is fitted the right way round.
- When re-assembling the nozzle holder, screw it down manually,
forcing it slightly.
- Never ever fit the nozzle holder before you assemble the
electrode, distributor ring and nozzle.
- Do not keep the pilot arc struck in air for no reason as this will
increase electrode, diffuser and nozzle wear.
- Do not tighten the electrode too much as this could damage the
torch.
- Prompt, correct inspection procedures for the consumable parts
of the torch are essential for safe, correct operation of the cutting
system.
- If the insulation is damaged, with breakages, cracks or burns
etc., or if the electric leads are loose, the torch may not be used
because it does not satisfy safety requirements. In this case repairs
(extraordinary maintenance) cannot be done on the spot and the
torch must be sent to an authorised service centre, which will be
able to carry out the special tests needed after the repair has been
done.
Compressed air filter (Fig. G).
- The filter has an automatic condensate exhaust that is activated every
time it is disconnected from the compressed air supply.
- Inspect the filter regularly; if there is any water in the glass, try bleeding
it manually pushing the exhaust fitting upwards.
- If the filter cartridge is particularly dirty, it must be replaced to avoid
excessive load losses.
EXTRAORDINARY MAINTENANCE
EXTRAORDINARY MAINTENANCE
CARRIED OUT ONLY AND EXCLUSIVELY BY SKILLED OR AUTHORISED
ELECTRICAL-MECHANICAL TECHNICIANS AND IN COMPLIANCE WITH
THE TECHNICAL STANDARD IEC/EN 60974-4.
OPERATIONS SHOULD BE
WARNING! BEFORE REMOVING THE MACHINE PANELS AND
WORKING INSIDE IT MAKE SURE THAT IT HAS BEEN
SWITCHED OFF AND DISCONNECTED FROM THE MAIN
POWER SUPPLY.
If checks are carried out inside the machine while it is live, this may
cause serious electric shock due to direct contact with live parts.
- Inspect the inside of the machine regularly, with a frequency depending
on the amount of use and dust in the environment, and remove
dust that has deposited on the transformer, rectifier, inductance and
resistors, using a jet of dry compressed air (max 10 bar).
- Do not direct the jet of compressed air onto the electronic boards;
these can be cleaned with a very soft brush or suitable solvents.
- Take the opportunity to make sure the electrical connections are tight
and there is no damage to the wiring insulation.
- Make sure the compressed air circuit hoses and connections are intact
and leak-free.
- When these operations have been completed, re-assemble the panels
on the machine and tighten the fastening screws right down.
- Never ever carry out cutting operations with the machine open.
- After having carried out maintenance or repairs, restore the connections
and wiring as they were before, making sure they do not come into
contact with moving parts or parts that can reach high temperatures.
Tie all the wires as they were before, being careful to keep the high
voltage connections of the primary transformer separate from the low
voltage ones of the secondary transformer.
Use all the original washers and screws when closing the casing.
8. TROUBLESHOOTING
IF OPERATION IS UNSATISFACTORY, AND BEFORE CARRYING OUT MORE
SYSTEMATIC CHECKS OR CONTACTING OUR SUPPORT CENTRE, CHECK:
- The led is not on, signalling intervention of the safety thermal switch for
over or undervoltage or short circuit.
- Ensure you have observed the nominal duty cycle ratio; in the event
of intervention of the thermostatic protection, wait for the machine to
cool naturally, check the fan is working.
- Check the line voltage: if the value is too high or too low, the machine
remains blocked.
- Check there is no short circuit on machine output: in this case, proceed
to eliminate the problem.
- The cutting circuit connections are carried out correctly, particularly
the earth cable clamp is actually connected to the piece and without
inter-positioning insulating materials (e.g. paint).
MOST COMMONLY OCCURRING CUTTING DEFECTS
During cutting operations it is possible that defects occur, which are
not normally caused by operating faults in the system but by other
operational matters such as:
a - Insufficient penetration or excessive slag formation:
- Cutting rate too high.
- Over-inclined torch.
- Piece too thick or cutting current too low.
- In appropriate compressed air pressure-flow.
- Worn electrode and torch nozzle.
- Inappropriate nozzle-holder tip.
b - Arc transfer failure:
- Worn electrode.
- Poor contact of the return cable terminal clamp.
c - Interrupted cutting arc:
- Cutting rate too low.
- Torch-piece distance too high.
- Worn electrode.
- A safeguard has triggered.
d - Inclined cut (not perpendicular):
- Incorrect torch position.
- Asymmetric wear on nozzle hole and/or incorrect assembly of
torch components.
- Inappropriate air pressure.
e - Excessive nozzle and electrode wear:
- Excessively low air pressure.
- Contaminated air (humidity, oil or other contaminants).
- Nozzle holder damaged.
- Excessive pilot arc start in air.
- Excessive speed with smelted particles return on the torch
components.
- The average length of the cut.
- The air quality (presence of oil, humidity or other contaminants).
- Perforation of the metal or cut starting from the edge.
- The torch-piece distance is not appropriate when cutting.
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