helvi COMPACT 300 Betriebsanleitung Seite 30

• Hs/Af LED (or Af only) flashing or fixed
(depending on the generator) – The display
shows "A": rotate the adjustment knob pos.
2 to adjust the Arc Force value. The display
will show the set value.
• Use button 15A, 15B or 16A (depending on
the generator) to activate or exclude the VRD
function.
IMPORTANT: For further information on
parameter functions and regulation in
MMA welding, please read the paragraph
on "WELDING PARAMETER CONTROL
PANEL".
• Wait 5 seconds. The generator will exit the
automatic parameter regulation menu.
• Adjust the welding current using the knob
pos. 2 (lw LED on) or with the remote control
knob if the remote control has been activated
with button pos. 8 (flashing lw LED).
• The set current value depends on the ap-
plication of the welding, the type of electrode,
its diameter and on the instructions provided
by the electrode manufacturer (and present on
the packaging of the electrodes themselves).
• The table below contains basic information
regarding the range of currents used for each
diameter of electrode.
Electrode diameter Welding current
1.5mm
2.0m
2.5m
3.25mm
4.0mm
5.0mm
6.0mm
• The following instructions can be useful for
good welding results:
• Delicately use the electrode (to avoid deterio-
ration of the coating) to touch the piece which is
to be welded, to trigger the electric arc.
• After triggering the arc, keep the electrode
in position at an angle of about 45° and move
it from left to right to control the arc and the
welding range.
• The length of the arc is a function of the
electrode/piece distance.
• Variations on the welding angle may incre-
ase the size of the welding area, improving
the covering capacity of the slag.
• When the welding is completed, allow the
residue to cool down before removing it with
a toe-ended brush.
30
30A - 50A
50A - 65A
70A - 100A
100A - 140A
140A - 180A
180A - 240A
240A - 270A
Table 4
Warning:
• Protect your eyes;
• Avoid injuries to you and other personnel
when removing the residue with the toe-
ended brush.
Warning!
A bad start can be caused by dirt on the
material to be welded, by the incorrect
connection between the earth lead and
the piece to be welded, or by the impro-
per fixing of the electrode holder.
WELDING QUALITY
The quality of the welding depends mainly on
the skill of the welder, the type of welding (pi-
ping, plates etc) and the quality of the electro-
de. Prior to welding, select the most suitable
model and diameter of electrode, being par-
ticularly careful regarding its thickness, the
composition of the metal to be welded and
the welding position (flat, front, descending/
ascending vertical etc).
WELDING CURRENT
If current intensity is too high, the electrode
will burn too fast and the welding will be ir-
regular and difficult to control. If the current
is too low, you will lose power and the wel-
ding will be narrow, irregular, with easy at-
tachments 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