Cycle Function In Tig Welding; 4T Torch Button Function - Helvi COMPACT 400 Manuel D'instruction

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 (pos. 14) to select the wel-
ding procedure with the infusible electrode
(TIG).
• Use the button (pos. 15) to select the diffe-
rent welding modes:
(Note: Functions 2T/4T pulsed current and
the up-slope are available only on 415HF-
420HF/C generators; on 400-400C genera-
tors it is only possible to weld in direct current
in 2T mode)
• 2 Stroke – 2T LED on with fi xed light,
• 2 Stroke pulsed – 2T LED fl ashing,
• 4 Stroke – 4T LED on with fi xed light,
• 4 Stroke – 4t LED fl ashing.
• Press button pos. 16, 16B or 16A (depen-
ding on the generator) to activate the "menu"
or "set" function (depending on the generator)
to select and adjust the values (using knob
pos. 2) of the relative TIG cycle functions.
IMPORTANT: For further information on
parameter functions and regulations du-
ring TIG welding, please read the para-
graph on WELDING PARAMETER CON-
TROL PANEL.
• Wait 5 seconds. The generator will automa-
tically exit the parameter regulation menu.
• Adjust the welding current using the knob
(pos. 2; lw LED on) or the remote control
knob if the remote control has been activated
with the button (pos. 8; lw LED fl ashing).
• The set current value is subject to the ap-
plication of the welding, the diameter of the
infusible electrode and the thickness of the
pieces which are to be welded.
Note: For metal sheets up to 2 mm thick, it is
possible to work without fi ller, as long as the
edges to be welded are close to each other.
• The table below contains basic information
on the range of currents which can be used,
according to electrode diameter and to sheet
thickness:
32
1,0 30 - 60 1,0
1,5 70 – 100 1,6
2,0 90 – 110 1,6
3,0 120 – 150 1,6 – 2,4
5,0 190 – 250 2,4 – 3,2
6,0 220 – 340 3,2 – 4,0
8,0 300 – 360 4,0

CYCLE FUNCTION IN TIG WELDING

• Up-slope: Progressive increase of the wel-
ding current (limits the temperature shock of
the electrode)
• Welding current: This value is related to the
operational parameters (see Table 4).
• Down-slope: Reduces the crater at the end
of the welding.
• Final current: Refi nes the fi lling of craters
if this process was not completed in the pre-
vious phase.
• Post gas: Protects the oxidation of the pie-
ce and of the electrode when the welding is
completed.
• Pulsed current (when present): On thin
surfaces, it stabilizes the arc and reduces the
added heat.
2T/4T TORCH BUTTON FUNCTION
2T
MODE
Torch button pressed (ON)
Torch button released (OFF)
Welding current
• The advantages of the 4T function are:
• Welding is performed without the need to
keep the button pressed (automatic mode);
• The fi nal welding current (lcf) can be adju-
sted for value (manual, pos. 2) and time by
means of the torch button.
3 – 4 1,0
3 – 4 1,5
4 1,5 – 2,0
4 – 5 2,0 – 3,0
4 – 6 3,0 – 4,0
5 – 6 4,0 – 6,0
5 – 6 4 - 6
4T
MODE
Torch button pressed (ON)
Torch button released (OFF)
Welding current
Final current