Determining the duty cycle of a plasma cutter can be quite tricky because there is actually no universal standard among manufacturers. But the duty cycle is not something that is complicated, a sound understanding of it can really keep you with your machine.
The plasma cutter duty cycle of a given unit can be defined as the amount of time in an hour the plasma cutter can safely operate without the unit or torch shutting down from overheating or just overheating.
This is usually given as a percentage and is calculated by the amount of amperage the unit draws.
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Importance of the duty cycle of a plasma cutter
The mode of using a plasma cutting influences the importance of the duty cycle. Question yourself: “What types of jobs will be done by my plasma cutter mostly and the thickness of metals I will commonly be cutting and also where will I be cutting?” Most times, a higher or longer duty cycle demands larger power requirements as well as a larger price tag.
However, if it happens that you are working on long, time-consuming cuts or you are working in an automated set-up such as a CNC type of setup, know that the starting/stopping or downtime is costly.
If you are in need of a plasma cutter for your personal fabrication shop, you might need a duty cycle of 50% or higher for production purposes. Getting a plasma cutter with a large percentage and higher amp, therefore, implies that you are cutting more, generating more revenue and having less idle time.
So therefore, if you’re utilizing your plasma cutter for shorter periods of time, which might be small DIY jobs, artistic jobs or just general cutting, the duty cycle might be less important for your needs. If it is just for home usage or occasional use, it is possible to easily get by with a model that has a 35% duty cycle at the same rated output.
Furthermore, the plasma cutter duty cycle is dependent on a defined speed of cutting. The manufacturer usually provides cutting speeds for all thicknesses of metals. You can measure it in IPM (inches per minute). If the metal you cut most frequently says quarter inches, a machine that offers a higher amperage will be able to cut through the metal much faster than another that has a lower amperage rating even though the two can get the job done.
A good rule of thumb to ensure for production cutting is ensuring that you choose a machine that can handle about twice your normal cutting thickness. The amperage requirement is dependent on the thickness of the metal and this can influence your duty cycle.
In addition, there is one more factor to put into consideration the duty cycle that many people don’t talk about which is the ambient temperature. Hence, the plasma cutter duty cycle makes up the amount of time in one hour the cutter can safely operate.
To know how you should utilize your cutter in relation to the duty cycle is of great importance due to the fact that if you go above your duty cycle, you risk damage to your plasma cutter system else you get to take a break while the plasma cutter cools down.