Full Product Manual

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TERMS RELATED TO AC TIG FUNCTIONS
AC Balance. This refers to the amount of time that the AC wave form stays at either positive or negative polarity. In simple terms
the amount of time that the unit spends in either positive or negative polarity can be skewed one way or the other to favor more
Electrode positive, or more Electrode negative as the AC wave form cycles. This is the “balance” of the wave form. When applied
to welding, the AC wave form can be divided into penetration and cleaning (the cathodic etching which removes oxides from the
weld). Electrode positive is responsible for the “cleaning” portion of the cycle and Electrode negative is responsible for the pene-
tration portion of the AC cycle. With the Lightning MTS, the unit displays cleaning as a percent (%) of electrode positive. As
discussed, this represents the amount of cleaning achieved. For best all around results, set AC balance to 25 to 35% to begin.
AC Frequency. This refers to the number of times per second that the AC wave form cycles one full time between Electrode nega-
tive and Electrode Positive polarity. One cycle is one Hertz. On this unit AC frequency ranges from 20Hz to 200Hz.
AC Wave Form. This unit features the ability to select 4 distinct AC wave forms, which include Advanced Square-wave, Soft
Square-wave, Triangular Wave, and Sine wave. AC wave form controls many different aspects of the welding process while weld-
ing Aluminum. Typical old-style transformers feature only a sine wave form, which is the same type of wave form created by pow-
er-companies and is the wave form that powers all AC devices, including welders in the US. However, with inverter technology,
the wave form can be manipulated into different AC wave shapes. When applied to welding, these wave forms affect and control
the intensity of the arc, wet-in of the puddle, and even the sound of the arc. Typically the Advanced Square wave offers the most
heat input and the fastest wet-in of the puddle. The Soft Square wave, offers a smoother feel, but is less aggressive than the Ad-
vanced square wave. This is closer to the style of more modern square wave transformer welders. It’s a good all around wave
form, but isn’t the most efcient or powerful. The triangular is the best wave form to use for thin gauge Aluminum. The triangular
wave shape only spends a brief period at the peaks of the wave, which meets the Amperage set, but only for a fraction of the time a
Square wave does, which spends the maximum amount of time at the peak of the wave form. This offers a cooler, less aggressive
arc perfect for welding thin materials. The Sine Wave form, as mentioned offers a older transformer type feel. In terms of heat
input in the weld, it falls between Soft Square Wave and Triangular Wave forms. The sine wave welds much slower at the same
amp output than the Advanced Square wave, allowing more heat to build in the surrounding metal.
Arc Start Type. There are two basic forms of Arc starting that may be selected in manual mode, The user may select from either
High Frequency (touchless) arc starting or Lift Start (Lift Arc) . High Frequency start sends an HF impulse to the torch tip to jump
the gap between the Tungsten and the workpiece which establishes a circuit path for the welding arc to follow and ignite. Lift Start
which uses the torch switch or foot pedal to send a low current to the Tungsten tip. Once the tip of the Tungsten is touched quick-
ly to the work and raised up in a seamless motion, the welder senses the contact and sends full current through to the tip as it
breaks contact with the work, igniting the arc. (See instructions on TIG arc starting later in this manual.)
Amps. (A) Amps are the measurement of the “pressure” of the electricity. Depending upon wave form, the display may read lower
while welding than what is set, because the hall effect sensor measures and reports the average Amperage of a wave form, and not
the peaks. This includes Pulse Amperage as it reports an average Amp value. Changing the Wave-form or Changing the Pulse
settings affects the average Amperage. NOTICE: When the foot pedal mode is activated, the unit will display selected maximum
Amperage for a few seconds before defaulting to display the minimum welding Amperage. This is because the Amperage signal at
the foot pedal is at the minimum position. When the foot pedal is pressed, or the torch slider is increased, the display will continue
to reflect the Amperage dictated by the position of the pedal/slider. To recall the selected maximum Amperage, tap briefly on the
pedal, or slightly rotate the top right control knob. In 2T or 4T mode, the selected amperage will continue to display until the arc is
struck. After that the Amp display displays actual amp output, which may vary slightly from the preset Amperage.
Control. The Control setting governs the function of the torch switch and foot pedal. The control offers several modes which in-
clude 2T, 4T, Pedal, 2T Finger and 4T Finger. The Pedal mode allows the unit to be controlled by the foot pedal or a torch slider
or similar amptrol. 2T mode and 4T mode offer two modes used with the torch switch that is included with the TIG torch. This is
used to control the torch cycle through preset functions of Pre/Post Flow, Up/Down Slope, Start/End Amps. In 2T mode, the
torch switch is simply pressed and held to cycle the torch. Once arc termination is desired, the switch is released. In 4T mode,
the Torch trigger is held down to start the pre-flow and initiate the arc at the “Start Amp” setting. The switch is then released and
the unit begins up-slope until it reaches the welding current. The weld is continued without the switch being pressed. Once the
weld is nearing nish, the torch switch is once again pressed and held to down slope to the “End Amp” setting. Then the torch is
released to terminate the arc and begin post flow. The addition of the Finger 2T and 4T is simply a type of amptrol torch which
utilizes separate switches along with an amp control mounted on the torch. Rather than a slider which has the on/off switch built
into the movement like a foot pedal would have, the switch is independent from the potentiometer. (In the Power-Set mode this is
also referred to as “Remote” when selecting a start type which combines start type and control type together.)
Section 2 Setup Guide
UNDERSTANDING AC TIG FUNCTIONS