Migatronic PI 250 DC HP Manuel D'instruction page 17

TIG tack welding TIG-A-TACK
The machine offers one tack welding function in the
individual program to allow quick switch-over from
welding to tack welding. In TIG DC the following features will
be available:
Arc ignition HF 2-times
-
- No slope-up/slope-down
- No pulse
- Reuse of pre-gas/post-gas values from the current
program
- Spot TIME from 0.01 to 2.5 secs in steps of 0.01 sec.
Set the value by selecting the parameter "spot time"
.
Electrode welding (MMA)
Is used for selection of electrode
welding. It is not possible to change
welding process during welding.
Hot start
Hot start is a function that helps to establish the arc
at the beginning of MMA welding. This can be
achieved by increasing welding current (when the electrode
is applied to the workpiece) in relation to the set value. This
increased start amp is maintained for half a second, after
which it decreases to the set value of welding current.
Amp
0,5 s
Set welding
current
Welding
start
The hot start value reflects the percentage value by which
initial current is increased, and can be set between 0% and
100%.
Arc-power
The arc power function is used to stabilise the arc in
MMA welding. This can be acheived by increasing
welding current during the short-circuits. The additional
current ceases when the short circuit is no longer present.
Amp
Set welding
current
Arc power can be adjusted between 0 and 100% of the
welding current setting.
E.g. If the welding current is set to 40 A and arc power to
50% the additional current is 20 A equals 60 A when
doing arc power. If the arc power is set to 100% the
additional current is 40 A equals 80 A when doing arc
power.
TM
Additional
current supply
from hot-start-
function
time
Additional current
supply from the arc
power function
short-
time
circuit
Torch adjustment /
remote control – 7-poled plug
The regulation of welding current is made by means
of the torch potentiometer (optional). The maximum current
reachable is the level previously adjusted on the front panel.
The minimum current is 5A.
External adjustment –
8-poled plug (optional)
Can be used for foot pedal (optional) and remote
control units (optional) that use a 8-poled plug. The function
is used for arc ignition and adjustment of the current. The
maximum current reachable is the level previously adjusted
on the front panel. The actual current is shown on the
display. Start amp can be used as a setting of minimum
current as a percentage of maximum current.
Please note: The machine will automatically start in two-times in this
function when the machine uses a software version before 1.12.
Ignition methods
It is possible to choose between 2 different methods
of ignition for TIG welding: High-Frequency (HF) and
LIFTIG ignition. The ignition method cannot be changed
during welding. The LIFTIG ignition is active when the
indicator is illuminated. The HF is automatically active when
the LED is switched off.
HF-ignition
In HF-TIG ignition the TIG arc is ignited without contact. A
high-frequency (HF) impulse initiates the arc when the torch
trigger is activated.
The HF will not arise and the machine will stop if the
electrode is in contact with the workpiece. Detach the
electrode and start again.
LIFTIG-ignition
In LIFTIG ignition the TIG arc is ignited after making contact
between the workpiece and the tungsten electrode, after
which the trigger is activated and the arc is established by
lifting the electrode from the workpiece.
Trigger mode
Selection of trigger mode. Four-times trigger mode is
active when the LED is illuminated, and two-times
trigger mode is active when the LED is turned off. It is not
possible to change trigger method during the welding
process.
Two-times
The welding process begins by pressing the torch trigger.
Welding continues until the trigger is released again which
effects the slope-down period.
Four-times
The welding process begins by pressing the torch trigger. If
the torch trigger is released during the slope-up period
welding continues with the adjusted welding current. In order
to stop the welding process the trigger must be pressed
again for more than 0.5s after which the slope-down period
begins. The slope-down period can be stopped by releasing
the trigger. Thereafter the post-flow starts.
It is possible to configure the machine to work in 4 different
ways when this mode is selected.
For detailed information read the section "USER MENU"
conc. "4t.o."
Anti-freeze
This machine is provided with an anti-freeze control. The
anti-freeze-control reduces the current when the electrodes
stick to the weld piece. This makes it easier to break off the
electrode and welding can continue.
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