How arc initiation works for plasma cutting

How arc initiation works for plasma cutting


When it comes to plasma cutter start functions, you always get two answer:

When it comes to plasma cutter start functions, you always get two answer:

There are two methods used to create the plasma arc for plasma cutting, High Frequency ignition and Non High frequency ignition.

1. The most common is High Frequency, cause it’s very easy to build the arc and very economical. To generate plasma, this method uses a high frequency, high voltage spark. When the plasma torch touches the material to be cut, thereby closing the circuit, the spark fires into the torch head and plasma is created.

However High Frequency plasma cutter will produce a lot of Electro Magnetic Interference (EMI), so it is not good for CNC(Computer Numeric Control)plasma cutting operation.

2. Another method of arc ignition is Non High Frequency, It is called blow-back start technology, In this case contact start does not refer to the torch coming in contact with the work. With blow-back torches, before the trigger is pulled, the electrode and the grounded part of the torch are in contact. When the trigger is pulled the machine turns on the air flow while turning on the regular welding cutting voltage. The airflow causes the electrode to blow back out of contact, striking the arc.

These systems can be used around computers and sensitive electronic devices without causing electrical noise interference. But Non-HF plasma cutter will be a bit expensive than HF plasma cutter, cause Non-HF machine need to be equiped with high quality Non-HF torch.

When you are willing to buy a plasma cutter, you will    always met a option,HF with pilot arc or Non-HFwith pilot arc, So there comes a question, what’s the pilot arc?

A pilot arc is a non transferred plasma arc (seen as a bright blue flame when the torch is triggered in the air) that helps to transfer the main arc to the plate when the surface is painted, dirty, or has masking material that renders the surface non conductive.


For the home hobbyist or light construction applications, the CUT-40DI HF/Non-HF  Air plasma cutting system is ready to go for fast and precise cutting. Pilot Arc makes it easy to use even for first time operators.

· Extremely portable at only 34 lbs. (15 kg)

· Auto-reconnects for single phase 115/230V 50/60Hz input (CUT-40MV)

· For fast and quality cutting: 0.4in (10mm) at 500mm/min