Saf-Fro PRESTOTIG 200 AC/DC, Operator'S Manual, Page: 13 / 436

English 9 English
Output:
This section is designated to allow the operator to set the
desired output control method
1. 2
STEP
2. 4 STEP
3. ON: no trigger required to start.
Pressing the button assigned to OUTPUT selection will
toggle the illumination of the icon from left-to-right
AC Wave Shape:
These icons allow the operator to customize the arc-
performance for TIG welding in AC polarity only.
AUTO and Expert Mode:
By default the AUTO icon is lit. This means that AC
waveshape parameters are automatically managed
depending on the welding current. The only available
parameter is AC-Frequency.
AC-Frequency: This function controls the frequency of
the AC Wave shape in cycles per second
When AUTO is selected the relationship between
Amperage and Balance is shown in table below:
Table 2.
Amperage AC Balance %
I <= 50 60%
50 < I <= 93 65%
93 < I <= 120 65%
120 < I <= 155 70%
155 < I <= 200 70%
To enable Expert mode:

Push the AC WAVESHAPE button twice: The AUTO
icon will start to blink and the display will show the
message AUTO ON.

Turn the encoder to select AUTO OFF

Confirm the selection by pushing the AC
WAVESHAPE button again. The AUTO icon will turn
OFF and all the AC WAVESHAPE parameters will
become available.
To revert to AUTO mode perform again the steps above
pushing several times until AUTO icon will start blinking,
then select AUTO ON with the encoder.
In Expert mode the following parameters are available:
1. AC-Frequency: This function controls the frequency of
the AC Wave shape in cycles per second.
2. AC-Balance: AC balance controls the amount of time,
as a percentage, that the polarity is electrode
negative.
3. Electrode Negative/Positive offset: This function
controls the amperage setting for the negative and
positive side of the wave when TIG welding in AC
polarity.
The voltage display screen shows an abbreviated
description of the icon selected. The amperage display
screen shows the value to be adjusted.
Sequencer Functions:
The sequencer allows for the customization of the TIG
welding operation both in AC & DC- polarities. Pressing
the “Sel” button will cycle through the process graph.
Table 3.
Pre-Flow : Sets the time in
seconds gas will flow prior to
arc-start initiation
Starting Current: Sets the
starting amperage for the
process.
Initial Slope : Sets the time in
seconds it takes the starting
current to reach normal
operating amperage.
Operating Amperage : Sets the
amperage for all welding
process permitted.
Final Slope: Sets the time in
seconds it takes the operating
amperage to ramp down to the
Finishing current.
Finishing Current: Sets the
finishing amperage for the
process.
Post Flow: Sets the time in
seconds gas will flow after the
arc is terminated