Migatronic PI 250 AC/DC HP Manual De Instrucciones página 19

TIG welding
TIG welding
The parameters can be adjusted with the
control knob after they are shown on the
display. Press the relative key to select the parameter.
The relevant LED will illuminate.
Pre-flow [s]
Pre-flow is the period of time for which gas
flows after the torch switch is pressed and
before the HF arc is established, or until the torch is
lifted away from the workpiece in the LIFTIG process.
Variable 0-10 sec.
Start Amp [A%]
Immediately
established, the machine regulates the
welding current to the value stated in the Start Amp
parameter. Start Amp is set as a percentage of the
required welding current and is variable between 1-
200% of the welding current. Please note that values
higher than 100% generate a Start Amp bigger than
welding current.
Slope-up [s]
Once the arc has been established, the
welding process enters a slope-up stage
during which the welding current is increased in linear
fashion from the value stated in the Start Amp para-
meter to the required welding current. The duration of
this slope-up time is variable 0-20 sec in steps of 0.1
sec.
Second current level
Adjustable from 10 to 200% of welding
current. It is activated in four-times only by
pressing and releasing quickly the torch trigger.
Please note that values bigger than 100% generate a
second current bigger than welding current.
Slope-down [s]
When welding has stopped by activating the
trigger, the machine enters a slope-down
stage. During this stage current is reduced from
welding current to Final Amp over a period of time
called the slope-down time and variable 0-20 sec in
steps of 0.1 sec.
after the arc has
Final Amp [A%]
The slope-down stage is completed when
the current level has fallen to the value
stated in the Final Amp parameter. In 4-times it is
possible to continue in Final Amp mode until the
trigger is released. Final Amp is stated as a per-
centage of the required welding current and is variable
between 1 - 90% of the welding current.
Post-flow [s]
Post-flow is the period of time for which gas
flows after the arc is extinguished and is
variable 0-20 sec.
Spot time
The spot time in TIG is the time from the end
of slope up to beginning of slope down.
Therefore, during spot time the machine is welding
with the adjusted current. The LED flashes on and off
when the function is active.
Amp
Set welding
current
been
Set the timer before igniting the arc. The torch trigger,
depending from the selected torch mode can interrupt
the spot welding time. Variable 0,01-20sec: steps of
10msec up to 0,5sec, over in steps of 0,1sec. The
function is disconnected when the time is set to 0 sec.
When used during tack welding, the timer can be set
from 0.01 sec to 2.5 secs (See TIG-A-TACK).
Current type
It is possible to select either AC (alternating
current) or DC (direct current). In the TIG-
welding process, AC is used for welding of aluminium
and its alloys, while DC is used for the welding of other
materials.
AC-t-balance (based on time)
Adjustment of the refinement function during
the AC TIG welding of aluminium and its
alloys. The function is a balance based on time
between the positive and negative halfperiod.
Adjustment is possible between 20 and 80 percent as
the statement in percent is based on the negative part
of the period time. Adjustment continues until a suit-
able refinement zone is established around the molten
pool. Forcing the balance to 100% the machine will
execute one "preheating" action in positive polarity,
followed by standard continuous negative welding.
This function is intended to "clean" the material at the
beginning of each welding.
19
spot
welding time
slope-up slope-down
trig down ( ) / up ( )
time