Torch Maintenance - ELLETRO PLASMA Manual De Instrucciones

3.6 GOUGING
This operation permits to remove faulty welding, to divide welded
pieces, to prepare edges, etc. and is almost exclusively used
with manually-controlled torch. Nozzle D. 3 mm should be used
and spacer be fit into the nozzle holding bush. Spacer prevents
molten metal from burning the insulating material covering the
nozzle holding bush, while gouging. The power value to be used
is from 80 to 150A. This operation is carried out by keeping torch
tilted and advancing towards the molten material thus moving it
away by means of the out flowing compressed air. Torch is tilted
depending on the penetration to be obtained. As molten slag
tend to stick on spacer and nozzle it is recommended to clean
them often to prevent effects (double arc) destroying nozzle in
few seconds. Because of intense radiation emission (both
infrared and ultraviolet) the operator as well as persons nearby
are recommended to use proper protection.

3.7 TORCH MAINTENANCE

Always disconnect the unit before any repair of torch.
1) Replace wear parts (picture 11).
The parts subject to wear are electrode (2), diffuser (3) and
nozzle (4). Either part may be only replaced after loosening
nozzle holder (5).
Electrode 2 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 have the thread
unlocked. Lubricate the thread of the new electrode with
silicone lubricant (on supply with the unit). This new
electrode is required to be screwed in its housing and
locked without tightening.
Nozzle (4) should be replaced when its central hole is damaged
or enlarged with respect to the new part (see picture 13). Use of
worn electrode quickly wears out the nozzle. Excessive use of
electrode causes overheating and reduces the life of diffuser (3).
Make sure that after replacing it, nozzle (5) is tight enough.
ATTENTION Nozzle holder (5) should be only screwed on
head when electrode (2) diffuser (3) and nozzle (4) are
assembled.
2) Replace torch body 1 (see picture 11).
Withdraw the screw. Withdraw handle (9) from body (1) by
swaying it and making sure that button wires are not torn when
separating both parts. Withdraw the safety contacts wires.
Withdraw the contact. Unscrew fitting after cutting the insulating
hose. Assemble the new body of torch making all above
operations inversely. Fitting is insulated by shrink hose stuck to
the fitting when heated by a small source (ex. a lighter).
Before replacing handle make sure that cables are far away from
each other and that fittings are tightly secured.
3) Substitution of adapter 12 (see picture 11).
Remove ring nut and cut the clamps locking cable (10).
Loosen screw and extract cover. Extract the control cable pins
i and a and the red cable pins for pilot arc e and f. Cut the
insulating sheath and loosen the adapter body (12) from
connector (11). Fit the new adapter body carrying out all
previous operations in reverse order. Use sealing adhesive for
threads in order to lock the adapter body thread (12) on
connector (11). Pins i and a of the control cable should be
connected to contacts i and a of adapter body (12). Pins e and
f of the red cable for pilot arc should be connected to contacts
e and f of adapter body (12). Sheath acts as insulating
material and adheres to connector (11) after warming it up.
4) Replacement of cable (10) (see picture 11).
To replace cable follow instructions as per pos.2 and 3 and
connect.
N.B.: Fitting should be properly insulated.
5) Replacement of handle with button.
To replace handle with button it is required to follow
instructions as for pos. 2.
3.8 MAINTENANCE AND CONTROL
It is recommended to keep nozzle free from slag.
Avoid using sharpened bodies thus avoiding damaging the
nozzle hole. Even if the unit is provided with an automatic
device for water discharge, working whenever air feed is
closed, it is recommended to check from time to time that no
water remains in trap I of reducer. It is required to clean from
time to time the unit inside and make it free from metal dust by
means of compressed air. Operations to be carried out inside
the unit must be effected after disconnecting feed cable.
4 GUIDE TO POSSIBLE FAILURES
Failures that could occur during machine operation are listed
below, this list being by no means exhaustive.
Repair, if any, should only be carried out by qualified
personnel.
Primary and secondary windings of the service transformer are
protected by fuses. In case of failure, first action to be taken
will be checking if any fuse is burnt.
1) Starting:
A If turning the switch A on (picture 2), the net pilot lamp
lightens but the machine does not start and nothing happens
when the torch push-button is pressed, verify :
The efficiency of the service transformer and the continuity
−
of the electric circuits.
The efficiency of control circuits.
−
The presence of all the three phases in the machine's plug.
−
That the flange 1 (picture 3) is correctly assembled.
−
B If turning the switch A (picture 2) on the net pilot lamp
lightens, the machine does not start but air flows out of the
torch when the push-button is pressed, ensure:
That plant pressure is sufficient. The lamp signalling
−
insufficient pressure may be faulty.
− That the microswitch of the air pressure switch or the
rectifier, or control circuit are efficient.
That spare parts: electrode (2, fig. 11), diffuser (3, fig. 11),
−
nozzle (4, fig. 11), nozzle holder (5, fig. 11) are correctly
assembled.
2) Pilot arc :
The duration of the pilot arc in air is approx. 2/3 sec., even
holding the torch push-button.
8