You’re probably quite familiar with the working of a plasma cutter by now. Compressed air is passed through a channel containing an electrode that is negatively charged. An electric power is applied to the electrode and when the pilot arc or the nozzle tip touches the metal, a circuit is completed and a spark is produced. The inert gas passing through the channel is heated by the spark and a plasma arc is formed, which has the capability to melt metal or cut through it.
The arc is produced continuously as long as the plasma is touching the metal being cut and the power is being supplied to the electrode. The plasma arc is very powerful and can slice through metals effortlessly. However, this also results in the consumables wearing out quickly. Many times, operators face problems with their plasma cutting machines which may not produce an arc or the plasma arc may behave erratically when cutting. In this article, we will examine some aspects that may help you diagnose any issues with your plasma cutter that can help you save time and further problems.
Slow Speed When Cutting
When you are using the plasma cutter, if the speed of cutting is very slow, especially if the amperage is high, the torch gets overheated and this can cause the consumables to wear out too soon. This can also cause the arc to stop completely.
Pulling the Nozzle Along the Workpiece
Many beginners make this mistake very commonly and drag the nozzle along the metal being cut. This may result in the nozzle getting overheated and the nozzle also gets exposed to slag causing the nozzle to wear out very quickly.
Attempting to Produce an Arc with Inadequate Air Pressure
The plasma arc can overheat the electrode and burn up the tungsten element present in the middle of the electrode if there is no air present to help cool the consumables in the torch. If you operate the plasma torch without turning on the air supply valve, you can damage the electrode instantaneously.
Ineffective Water Separation
The fire in the torch will be extinguished if there is water present in the air stream. This causes the plasma arc to be unstable and behave erratically. You must ensure that your compressor is equipped with an in-line water separator or has a desiccant system. The plasma cutter’s internal water separator must be inspected and drained out regularly.
Length of the Extension Cord
If the length of the extension cord being used with the plasma cutter is too long or short, the quality of the cord is very low, or the gauge of the extension cord is too thin, then you may have a problem with producing a plasma arc or it may not be able to cut the required thickness of metal.
If the nozzle of your plasma torch has an enlarged or distorted centre, the focus of the plasma arc will be lost and the cutting will not be precise. If you do not replace a worn-out nozzle, it will burn the electrode and can also the tungsten element that produces the plasma arc. Finally, if the torch is operated without any air or the torch becomes too hot, then it can melt the diffuser or the swirl cup and the arc that is produced will be very unstable.
To ensure that your plasma cutter works efficiently and produces precise cuts, all the parts of the torch must be inspected on a regular basis. You must make sure that all the worn-out consumables are replaced immediately in order to get the best performance from your plasma cutter.
For any advice or to see how we can help, please don’t hesitate to get in touch. We’re always happy to help.