Migatronic PI 200 AC/DC HP Manuel D'instruction page 16

Start Amp [A%]
Immediately after the arc has been 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 parameter 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.
Please note:
The secondary current function will be deactivated at a
current value of 100%.
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.
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 percentage 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
slope-up
Set welding
current
Set the timer before igniting the arc. The torch trigger,
depending from the selected torch mode can interrupt the
spot welding time. Variable 0,01-20 sec: steps of 10 msec up
to 0,5 sec, over in steps of 0,1 sec. 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 suitable 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.
AC-frequency
The AC frequency can be adjusted from 25 to
150 Hz for TIG welding. A low frequency during TIG
welding increases the tendency for the formation of a large
ball at the end of the tungsten electrode. Increasing the
frequency will reduce this tendency. The frequency for MMA-
welding can be adjusted from 25 to 100 Hz. Forcing the
frequency to 0 Hz in MMA just reverse the polarity of
electrode (+/-), avoiding the need of exchanging electrode
clamp and ground cable.
Maximum AC frequency as function of welding current
16
spot
welding time
slope-down
time
trig down ( ) / up ( )