For your RED TIG welding machine to work optimally, the torch and ground cable must be connected correctly.
The material to be welded determines whether you weld with direct current (DC) or alternating current (AC).
Here you will learn how to properly connect the hose package and the ground lead:
DC Welding (Direct Current)
DC welding (Direct Current) is used for most metallic materials – e.g. steel, stainless steel, copper or titanium.
The connection always remains the same:
Torch / electrode to negative pole (–)
Ground cable to positive pole (+)
This polarity ensures a concentrated arc, deeper penetration and a long electrode life.
Typical applications:
Structural steel
Stainless steel
Copper
Titanium
AC Welding (Alternating Current)
AC welding (Alternating Current) is mainly used for aluminium and aluminium alloys.
Aluminium forms a stubborn oxide layer on the surface that hinders the welding process.
This oxide layer is automatically removed during AC welding, because the machine constantly switches the current flow between positive and negative poles.
In the negative phase (electrode –), the workpiece is heated and penetration is created.
In the positive phase (electrode +), the oxide layer is cleaned.
Important:
Whether in DC or AC mode – the torch is always connected to the negative pole (–),
the ground cable to the positive pole (+).
The phase-wise polarity reversal in AC is automatically controlled by the machine.
Manual polarity switching is not necessary.
Notes
Make sure the ground connection is firm and cleanly connected to the workpiece to ensure good contact.
Ensure that the ground connection is as close as possible to the welding point to avoid voltage losses.
For aluminium, the surface should be clean and metallic to support the cleaning effect of the AC function.
Please note
Not all TIG welding machines support both types of welding current.
Pure DC machines – such as the RED TIG 180 DC – are designed exclusively for direct current welding (DC).
With these machines, you cannot use alternating current (AC), which means they are not suitable for aluminium welding.
If you want to weld aluminium or aluminium alloys, you need an AC/DC TIG welding machine that supports automatic switching between positive and negative poles (AC operation).
If you are unsure which process or setting you need for your material, you will find guidance in the user manual of your RED TIG device or you can contact us directly via the contact form.