How does a Plasma Cutter Work?

As you know, a plasma cutter is a machine designed for cutting mainly metal materials. Rather than cutting with oxy-fuel, it transfers energy from a power source to a conductive material using an electrically conductive gas. When compared with oxy-fuel, cutting with a plasma cutter is not only faster but also cleaner thanks to this process. The inventors of this machine took the idea from the ability of matter to change from one state to another when heat is applied to it. There are a number of gases that can be used in plasma cutter. Typical examples of gases that can be used are oxygen, argon, shop air or nitrogen.

When any of these gases are released forcefully via a nozzle orifice inside the torch, the plasma arc begins to form. An external power supply is used to generate an electric arc which will be introduced to this high pressured gas flow which will give rise to what is called the plasma jet. The temperature of the plasma jet will rise up to 40,000 F degrees making it possible for the gas to get to a plasma state (which is the fourth state of matter). With this high temperature, it will be able to cut through the work material. The molten material generated is also blown away due to the force. The metal material being cut is a conductor and thus it becomes part of the circuit. The arc is transferred to the work material thanks to the electrical conductivity of the plasma.

Plasma cutters come with a number of parts that have to function together for the plasma to cut. It is important that you know these parts and their functions to be able to understand fully the working mechanism of plasma cutter. Below are the important components of the plasma cutter that you should know.

Components of a plasma cutter

Plasma torch

The plasma torch is the part that keeps the consumables in alignment. It also cools them. The consumables come with parts required for the generation of the plasma arc. These parts are the nozzle through which the air is released, the swirl ring and the electrode. They have inner and outer retaining caps that are used to hold the parts together.

plasma torch parts

Arc starting console (ASC)

The AC voltage of about 5,000 VAC is generated by the ASC circuit at 2 MHz. The spark inside the plasma required for the creation of the plasma arc is generated by this voltage.

Power supply

The power supply of a plasma cutter is the source of power. The plasma cutter uses both AC and DC voltage. The AC line voltage is converted by the plasma power supply into DC voltage which ranges from 200 to 400VDC. The current output is also regulated by the DC voltage.

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