Miller Electric

Help Me Choose

Home » Products » Help Me Choose » Selection Guide

6. Understand Duty Cycle

One way of classifying a welder's "size" is by how much amperage it can generate at a given "duty cycle." Duty cycle is the number of minutes out of a 10-minute period a welder can operate. For example, the Dynasty® 350 TIG unit can deliver 300 amps of welding output at a 60 percent duty cycle. It can weld continuously at 300 amps for six minutes, and then must cool down during the remaining four minutes to prevent overheating.



When considering duty cycle for a Stick machine, note that most Stick electrodes are consumed in less than two minutes. Further about 80% of all Stick welding is done with a 1/8-inch diameter electrode, which takes about one minute to consume.

To see if a machine meets your needs, consider the following power classifications.

  • Light Industrial products typically have a 20% duty cycle and a rated output of 230 amps or lower.
  • Industrial products typically have a 40-60% duty cycle and a rated output of 300 amps or lower.
  • Heavy Industrial products typically have a 60-100% duty cycle and a rated output of at least 300 amps.


Previous  |  Next


Powerline Financing