When evaluating a plasma system, power is a cut above amperage

By Vince Tucker, Hypertherm District Sales Manager
Posted on 10/27/2020 in SPARK the blog, Plasma cutting

When it comes to designing and manufacturing plasma cutting machines, Hypertherm puts the emphasis on cutting POWER, so much so that we even named our line of air plasma cutters the “Powermax®". ...So why does Hypertherm care so much about power, and why should power be important to you?

Plasma cutting amperage

People in welding and cutting industries often talk about machine output in terms of amperage and purchasing decisions are regularly based on amperage numbers. If two cutters made by different manufacturers have the same amperage, then the assumption is they must be equal. This is reasonable thinking; however, amperage is only part of the story.

A true apples-to-apples comparison between plasma cutters will also consider the design of the machine because it impacts what can be done with those amps. Unfortunately, two plasma cutters with the same amperage will cut and perform differently. That’s because amperage by itself does not equal power.

So, what is power?

Simply put, power is measured in kilowatts (amperage x voltage). The number of kilowatts is what truly qualifies a plasma cutter for the job. If a manufacturer is only talking about amperage, they’re not giving you the whole story. That’s why Hypertherm includes all these numbers (amperage, DC voltage output, and kilowatt output) in our product specifications in our brochures, operator manuals, and on our website.

Take Hypertherm’s Powermax65® for example (amperage x voltage = kilowatts/power). It’s a 65-amp system with 139 volts of output power. When you multiply these two numbers (65 x 139), you’ll get 9,035 watts. That’s more than nine kilowatts of pure cutting power! This means the Powermx65 actually has more output power than a competitor’s 80-amp system (only 8,960 watts).

How does the Powermax65 compare to a competitor’s plasma cutter with a 60-amp output? For the full story, multiply the amperage by the DC volts. The competitive system when dialed to full output has 60-amps available for cutting at 126 DC volts (60 x 126). It yields only 7,560 watts while the Powermax65 has 9,035 watts of cutting power. The Powermax65 has 16% more power.  

Operating costs

Having more power at a lower amperage will have a positive impact on operating expenses. A plasma cutter with a lower amperage could cost less and it will consume less power.

The 80-amp plasma cutter from the example above requires 72-amps of input power at 240 volts to operate at full power, while the Powermax65 only requires 44-amps of input power at the same voltage. This difference of 28-amps of input power between the systems means the Powermax65 will use less electricity, operate more efficiently, and save you more money over time.


Some plasma systems provide more power than their competition. Hopefully, this post makes it clear as to why purchasing decisions should not be based on amperage alone, and that wattage is the better indicator of machine capabilities and performance. 

If you still have questions, email the Hypertherm team at information@hypertherm.com.