Full Product Manual

92
TIG OPERATION AND THEORY
Section 3 Basic Theory and Function
NOTICE:
• Due to the rapid switching of the inverter, High Frequency (HF) is not used for anything except starting the arc. The HF TIG only refers to
the initial arc start, and can be used for DC as well. In a transformer welder, the HF could be switched to continuous to stabilize the AC arc,
but in an inverter, this is not necessary. So, the HF switch refers only to the Start of the arc, and not to AC operation. However to reduce
tungsten contamination with aluminum, you should only operate the AC mode with the HF start selected.
• Lift start is recommended only for DC, or for AC when a copper scratch block is used and the arc is transferred. Lift start would be used in
areas that are sensitive to electronic interference such as hospitals or computer/CNC equipment.
• The addition of Helium to Argon can increase the welding capacity of the welder and alter the amount of cleaning typically needed. Do not
exceed 25% however or arc starts will be difcult and erratic.
• If arc wandering in AC is a problem, reduce cleaning percent, then if it continues, reduce gas flow and then check for drafts or for poor
work clamp connection. Also check for highly oxidized or dirty aluminum or a faulty work clamp or connection.
• AC controls only apply to AC operation, and do not affect the settings on DC.
• Too slow of travel speed will increase the etching/cleaning area.
• AC balance on this unit registers as a percent of positive! This is different from some brands which orient there units toward percent nega-
tive. The Lightning MTS unit should typically have an AC balance setting of 30%, instead of 70% used with some other brands. In refer-
ring to AC balance, it is common to refer to the “amount of cleaning” that is being achieved. Cleaning is a function of Electrode positive
and is the reason that the Everlast unit (along with several other brands) refers to AC balance as a percent of full Electrode Positive polarity.
DO NOT TRY TO REVERSE POLARITY OF TIG TORCH TO ACHIEVE THE VALUE OF 70% TO CONTROL THIS UNIT, OR OVERHEATING
AND DAMAGE MAY OCCUR.
• Do not ball Tungsten. Using a sharp or slightly blunted tapered tip offers the best arc stability and welding performance. As you weld, the
point will gradually fade into a “bullet” or “dome” shape, without a ball. If you get a ball on your tungsten, you are either 1) Using too much
amperage for the Tungsten, 2) Using too high of an AC balance setting, 3) Using the wrong polarity for the torch (TIG torch is always
negative, even in AC). 4) Using a gas mix with CO2 (Use pure argon only) or 5) Operating your unit too close to the weld area and the 4
fan cooling system is blowing the shielding gas off the weld. Move the welder at least 8 feet from the work area if possible.
• The AC port is to be used only with the work-clamp, only in AC (Aluminum) TIG. Do not forget to change the work clamp from the DC+ to
the AC port, when welding AC, or irregular operation will occur, with high potential for machine damage.