Migatronic PI 250 MMA, Instruction Manual

Page: 9 / 50

9
CONTROL UNIT
Control knob
All parameters are set by the use of only
one control knob.
This control knob is positioned in the right
side of the control panel. The digital display
shows the value of the parameter being set. The unit
of measurement of the parameter is shown on the
right side of the digital display.
A parameter can be selected by means of the relative
keypad in the relevant section. A bright indication light
indicates the parameter selected. The control knob is
then used for setting a new value.
Welding current/Arc voltage
The key pad can be used to display the
welding current. Adjustable from 5A to 500A
depending on the model. After the welding process
has stopped, the adjusted current is shown on the
display. During welding, however, the actual welding
current is shown.
Press the key for 3 seconds to display the arc voltage.
Press again “A” to display the welding current
.
Units for parameters
Units of measurement of the selected
parameter.
Welding voltage indicator
The welding voltage indicator is illuminated for
reasons of safety and in order to show if there is
voltage at the output taps.
Overheating error indicator
The overheating indicator is illuminated if
welding is interrupted due to overheating of the
machine.
Mains error indicator
The mains error indicator is illuminated if the
mains voltage is more than 15% lower than the rated
voltage.
Ignition method
It is possible to weld in TIG by LIFTIG ignition.
The procediment LIFTIG is active when the
indicator is illuminated.
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.
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.
Set welding
current
Welding
start
0,5 s
Additional
current supply
from hot-start-
function
time
Amp
The hot start value reflects the percentage value by
which initial current is increased, and can be set
between 0% and 100%.