Setting At Work - Cebora Plasma Prof 35 Manual De Instrucciones

This machine is suitable for CEBORA torches type P.70
and P.150 only, either manual or straight, and CEBORA do
not assume any responsability in case that a different kind
of torch is used.

SETTING AT WORK

The unit must be installed by skilled personnel. All
fittings must be in conformity with the existing rules and
in full compliance with safety regulations.
Connect the air feed to fitting B making sure that pressure is
88PSI (6bar or KPa X100) at least with a minimal capacity
of 420 CFH (200 liters/min.)
Should air feed come from a pressure reducing unit of a
compressor or of a centralized plant, the reducing unit should
be adjusted at the highest output pressure which should not
exceed 120 PSI (8bar or KPa x100). Should air feed come from
a compressed air bottle, this should be provided with a
pressure regulator; never connect compressed air bottles
directly to the reducing unit! Pressure may exceed the
reducing unit capacity and then explode!
Check that the mains power supply matches that indicated on
the rating plate attached to the power supply cable. If this is not
the case, change the connections on the change voltage
terminal board inside the equipment.
Connect supply cable A: the yellow-green wire of cable must
be connected to an efficient earth plug of the system, the
remaining wires should be connected to the feed line by means
of the switch placed, if possible, close to the cutting area so
as to switch the unit off quickly if necessary.
The magnetothermic switch capacity or of fuses in series with
switch should be equal the current I
Current I absorbed is known by reading the technical
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specifications on the unit i.e. feed voltage U
Any extensions should have adequate sections for current
absorbed I .
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USE
Switch the unit on by turning knob C of the mains switch; this
is shown by light D which is on.
By pressing for a second the torch button, the compressed air
flow is opened. Check that, under this condition, the pressure
shown on gauge F is about 75 PSI (4,5"4,7 bar or KPaX100),
otherwise adjust it by means of knob E of reducing unit, then
lock this knob by pressing it down.
Connect work clamp H to the piece to be cut.
Set the cutting current by means of the knob M.
Use the > 1 mm nozzle up to 45"50 A and the > 1,2 mm one from
45 to 70 A.
N.B. Cut quality is greatly improved if the nozzle is kept at
a distance of approx. 2 mm from the workpiece. Often for
practical reasons, however, cutting is performed with the
nozzle in contact with the workpiece. Cutting with the
nozzle in contact with the workpiece must not be performed
at currents above 45A as this leads to rapid (sometimes
even instantaneous) destruction of the nozzle hole; this in
turn leads to poor cutting quality.
When the red warning light (O) lights up this indicates that
cutting must be performed using the spring (part no 1394)
or the spacer (part no 1405).
Clean the work piece to ensure good electrical contact of the
work clamp.
Do not connect work clamp to the material to be removed.
Press torch button to start pilot arc, if cutting does not start
after 2 or 3 seconds, the pilot arc turns off and the button should
be pressed again to repeat the operation.
When possible, the torch should be pulled. Pulling is easier than
pushing.
Keep torch in vertical position when cutting.
Once cutting is over and after releasing button, air continues to
flow out of the torch for about 40 seconds so it enables torch to
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absorbed by the unit.
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available.
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cool down. It is recommended not to turn the unit off before that
time.
Should holes be drilled or should the piece be cut starting from
its center, torch should be tilted and then slowly straighten to
prevent molten metal from being spread on nozzle (see picture
4). This operation should be carried out whith material thick-
ness above 1/8"(3 mm). If you have to cut near angles or
recesses (see picture 5) it is recommended to use extended
electrodes and nozzles.
Should circular cut be done it is recommended to use caliper
(supplied on request).
N.B. : Avoid keeping pilot arc uselessly on, in air to avoid
electrode, diffuser and nozzle consumption.
CUTTING TROUBLE
1) Insufficient penetration
This may be due to:
• high speed. Always make sure that arc thoroughly passes
through the piece to be cut and that it is not tilted, when going
forward, by a percentage above 10 " 15° (see picture 6). It is
thus avoided to wear nozzle (see picture 7) out and to burn
the nozzle holder (see picture 8).
• Excessive thickness of piece (see graph of cutting speed and
thickness)
• Work clamp H not properly in electric contact with piece
• Worn nozzle and electrode
• Too low cutting current.
N.B. : When the unit does not thoroughly pass through, nozzle
is clogged by scums.
2) Cutting arc switches off
This may be due to:
• worn nozzle, electrode or diffuser
• too high air pressure
• too low feed voltage
3) Tilted cutting
When cutting is tilted (see picture 9) switch the unit off, loosen
nozzle holder and turn nozzle by a quarter turn, then lock and
try again.
Repeat until cutting is straight (see picture 10).
4) Excessive wear of consumable parts
This may be due to :
a) too low air pressure with respect to the recommended one
b) excessive burns on the end part of nozzle holder.
PRACTICAL RECOMMENDATIONS
• If the system air contains much humidity and oil it is required
to use a drying filter to avoid excessive oxidation and wear of
consumable parts, to avoid torch damage or to reduce speed
and quality of cutting.
• Impurities of air favour oxidation of electrode and nozzle
and make it difficult to start pilot arc. If this occurs, clean the
end part of electrode and inside the nozzle with fine abrasive
paper.
• Make sure that new electrode and nozzle to fit are clean and
degreased.
• To avoid damage of torch always use original spares.
TORCH MAINTENANCE
Always disconnect the unit before any repair of torch.
1) Replace wear parts (picture 11)
The parts subject to wear are electrode A, diffuser B and nozzle
C.
Either part may be only replaced after loosening nozzle holder
D.
Electrode A should be replaced when a 1/16"(1.5 mm) deep
crater is created in the middle (see picture 12).
ATTENTION! Do not make sudden stresses when
unscrewing the electrode, but gradually force so as to