Welding With Infusible Electrode (Tig); Completing The Tig System With An Air Cooled Torch - Helvi COMPACT 246HF Manual De Uso

WELDING CURRENT
If current intensity is too high, the electrode
will burn too fast and the welding will be irre-
gular and difficult to control. If the current is too
low, you will lose power and the welding will
be narrow, irregular, with easy attachments
between the electrode and the piece.
ARC LENGTH
If the arc is too long, it will result in dripping
and in a small fusion of the piece being wor-
ked. If the arc is too short, the heat will not be
sufficient and the electrode will attach to the
piece being worked.
WELDING SPEED
Using a suitable welding speed, according
to the parameters employed, will allow for a
welding seam of the right size and with the
proper penetration.
WELDING WITH INFUSIBLE
ELECTRODE (TIG)
TIG welding with direct current is specifical
ly used to weld steel and stainless steel. For
these types of welding, it is advisable to use
non pure tungsten electrodes (not green).
The tip of the infusible electrode is tapered so
that the arc is stable and the energy is con-
centrated on the contact point/area which is
to be welded. The length of the tapering will
depend on the diameter of the electrode: with
low current, tapered tip with tapering length
l = 3 x d; with high current, rounded tip with
tapering length l = 1 x d.
The triggering of the arc in TIG may be per-
formed with peaks of high voltage at high fre-
quency; this solution (HF system) does not
require contact between the electrode and
the piece in order to trigger the welding arc.
To trigger the arc without HF the electrode
must come into contact with the piece (Lift
Arc system).
COMPACT 246HF comes with HF.
Triggering the electric arc in Lift-Arc requi-
res contact between electrode and the piece
EN-14
Fig. 15
when the torch trigger is pressed.
The operational phases of the Lift Arc system
are:
• Lightly press the electrode on to the piece
which is to be welded (1).
• Press the torch button. The gas will flow
and the current will pass through the electro-
de.
• Move the electrode away from the piece,
rotating it so that the nozzle of the torch re-
mains in contact with the piece (2-3).
• The arc has now been established and the
current will reach the level of welding set be-
fore (4).
Fig. 16
COMPLETING THE TIG SYSTEM
WITH AN AIR COOLED TORCH
• Connect the ground lead to the positive
(+) socket of the generator (pos. 5) and the
ground pincer to the piece which is to be wel-
ded.
• Connect the power cable of the torch to the
negative (-) socket of the generator (pos. 4)
and connect the torch button cable to the 12-
pole socket on the generator (pos. 7) (PIN 1
& 2).
• Connect the gas tube to the "gas connec-
tion" located on the rear panel of the gene-
rator (pos. C) and to the pressure reducer
assembled on the suitably fixed cylinder.
(Note: The gas which must be used is pure
argon; for further information on "PROTEC-
TION GAS CONNECTION", please read the
relative paragraph).
• Hold the torch without pushing the trigger;
supply voltage to the generator using the
start/stop (ON/OFF) switch assembled on the
rear panel (pos. A) of the generator (Warning:
The welder will suggest the settings used in
the previous welding).
• Use the button T2 to select the welding pro-
cedure with the infusible electrode (TIG).
• Use the button T4 to select the different
welding modes:
• 2 Stroke – LED L7 on with fixed light,
• 2 Stroke pulsed – LED L7 flashing,
• 4 Stroke – LED L8 on with fixed light,
• 4 Stroke – LED L8 flashing.