What is Duty Cycle on a Welder? Preventing Overheating

what is duty cycle on a welder

One of the crucial factors to know when using a welding machine is duty cycle. The duty cycle in welding is used to define the number of minutes (within 10 minutes) during which the welder can safely produce a particular welding current and how long it can work before it overheats.

Cucial Factors: The Duty Cycle

One of the crucial factors to know when using a welding machine is the duty cycle. The duty cycle in welding is used to define the number of minutes (within 10 minutes) during which the welder can safely produce a particular welding current and how long it can work before it overheats.

Duty Cycle Welder Definition: How to Calculate The Duty Cycle

The duty cycle is calculated by dividing the pulse width (pulse active time) by the total period of the signal and then multiplying the outcome by 100%.

So, if the active time is 0.02 seconds, and the entire signal period is 0.05 seconds, the duty cycle equals 0.02/0.05 = 0.4, multiplied by 100, is 40%.

In other words, if the duty cycle is rated at 60%, the machine works 60% of the time and turns off for 40%.

Popular Example: The Miller Millermatic 211 MIG Welder

One of the most well-known welders is the Miller Millermatic 211 MIG Welder, which has a 30% duty cycle welding with an output of 150 A at 230 VAC.

Although the machine’s name suggests that it can weld up to 210A, its duty cycle is measured at 150 amps. According to the duty cycle formula, it can weld for 3 minutes and rest for 7.

Factors That May Affect the Duty Cycle

However, some people have reported that it cuts off before 3 minutes, which may have been caused by several factors:


The welding voltage is a significant factor that many don’t consider. If the voltage of a 30% duty cycle is increased from 23.5 to 25 volts, then the duty cycle would be lower, which means the welder may shut down after 2 minutes.

Environmental Temperature

Most duty cycles operate at an ambient temperature of 70 degrees Fahrenheit. However, suppose the temperature where you’re working is higher, at say 100 degrees, while you’re welding at 150 amps and 23.5 volts. In that case, the duty cycle will be much lower than 30%, despite the built-in cooling fan.


The machine must be in a well-ventilated area to operate at full capacity. The airflow generated by the built-in cooling fan will decrease. There must be at least 10 to 12 inches of space between the welder and the wall to ensure that it won’t overheat.

What Type of Welder is Best for Beginners?

If you’re an absolute beginner, then we’ve compiled a list of some of the easiest welding machines you can use:

Miller Electric 120/240v AC Welder for MIG Welding

Miller Electric is one of the most prominent companies in the industry, so it makes sense that it’s our top choice. This is one of the best welders for beginners due to its efficiency and dependable wire feed. The machine can weld various projects with different materials and thicknesses.

Unfortunately, it isn’t cheap, but it more than makes up for its power and versatility.

Hobart 500559 Handler Wire Welder

Hobart is another big company in the industry. This is a more affordable welder, perfect for beginners in the field. It’s great because it’s tuned to use any standard household current. It also has a range of 25 to 140 amps. It’s praised for its versatility as it’s capable of welding from 24-gauge to ¼” steel so that it can handle light household welding, as well as heavier jobs.

Lincoln Electric 140c MIG Welder

The Lincoln Electric 140C MIG welder it’s not cheap. Still, it’s definitely worth the price thanks to its high power and ease of use. It also has a range of 30-140 amps, just like the Hobart, which makes it perfect for any project, either simple household work or heavy-duty jobs.

Although it’s one of the most versatile machines on the market, the Lincoln Electric 140c MIG Welder only has a 20% duty cycle rating.


What is the thermal overload protection on a welder?

When the welder’s duty cycle exceeds the limit, the overload protection system interrupts the power supply to prevent damage from excessive heating to the machine.

What MIG welder has the best duty cycle?

One of the highest duty cycle welding machines is the Hobart Ironman 230 MIG Welder, which has a 60% duty cycle.

Alternatively, The Hobart Handler 190 has been announced as the best welder of 2019 in value for money. With a duty cycle of 30%, it’s easy to install and has seven voltage selections to choose from. It comes with a 5-year warranty as well.

What’s the best cheap welder?

Suppose you’re looking for a welder that won’t cost you much money regardless of its specs. In that case, you should try the Amico Dual Voltage Stick Arc MMA Welding Machine or the Super Deal Black Commercial MIG Welder, both of which are relatively cheap compared to other welding machines.

However, keep in mind that they won’t offer you the same power and efficiency as their more expensive counterparts.

What’s the best welder for home use?

The Lincoln Electric Handy MIG is commonly believed to be the best welder for home use. This lightweight welder can work on mild steel from 24 gauge to 1/8″ thick and can be plugged into the standard 115V, 20A outlet. It comes with a wide array of accessories for different uses.

What do the amps mean on a welder?

The correct amperage is essential to the quality of your welds. Amps are basically the welder’s heat to weld thin or thick materials.


This article provided you with some information you need to understand about the duty cycle and why they should always be considered when purchasing a welder machine.

Make sure to plan out your project and select your equipment according to your needs; otherwise, you will end up with an expensive purchase that you have no use for at all.

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