What is Duty Cycle in Welding?

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The duty cycle refers to the time you spend putting down the welding metal as a percent of the overall welding time taken to complete it.

For new welders, understanding the welding duty cycle can be challenging. Here we talk about what it means, how to calculate the duty cycle, and what forms they come in.

On a welding machine, the duty cycle is crucial. An intermittent duty device operates a large percentage of the time instead of being idle for long periods.

Essentially, this refers to the maximum time you can run a welder. Welder performance is measured over 10 minutes. Keep reading for more information.

How Is Duty Cycling Calculated?

A welding machine’s specification plate indicates the time in terms of a percentage. The duty cycle refers to a welding machine’s operation under a specific amperage. Based on the Australian Standard, the period should last 10 minutes at temperatures of 40 degrees Celsius.

For example, when welding small jobs, a DIY welder may run at a 20 percent duty cycle at its maximum amps, which may be 150 amps. 20 percent of 10 minutes is 2 minutes, so you can use 150 amps nonstop.

According to the specification plate, another duty cycle is the maximum amperage the welder can operate at 100% all the time. It lasts 10 minutes in total. If you are welding nonstop for that time frame, it helps you understand the amperage you can safely work at.

Do Duty Cycles Come in Different Forms?

Continual Duty

Duty cycles of this type are the simplest and easiest to understand. The machine’s motor is exposed to extended periods of operation to reach thermal equilibrium. During continuous duty, the machine’s operation duration will significantly influence its temperature.

Short Time Duty

Continuous duty is similar to its operation. Short-term duty operations are usually stopped before they reach equilibrium. Furthermore, a short-term duty usually requires more time for the machine to cool.

Periodic Duty

Whether there are breaks or not, duty cycles within S3-S8 are included in this category. Among the topics covered in this group are starting, swapping loads when in a break, and electric braking. Thermal equilibrium cannot be reached in this category.

How Should We Evaluate Welders Based On Duty Cycle?

Welders should not be evaluated solely based on their duty cycle. Choosing your machine also involves several other factors. The duty cycle is, however, an important specification to consider.

When you use a short-duty cycle welder at high amps and high volume, it will overheat continuously. In the same way, buying an expensive welder for amateurs or light shop welding would not be a good investment.

Aside from the duty cycle, welders should be evaluated according to their power output range, functions included, portable design, the quality of the construction, and, last but not least, warranty coverage. Welders with high-duty cycles that aren’t warranted for more than a year will likely wear out sooner than you expect.

After hitting two consecutive thermal overloads, it is unlikely that you can weld in an environment with an ambient temperature of 40°C. As a result, regardless of the machine you choose, the duty cycle is likely to be greater than that specified on the label for an AS/EN60974-1-compliant machine.

In the Case of a Duty Cycle Going Beyond, What Occurs?

The thermal overload protection is activated once the duty cycle of a welder has been exceeded. This safety measure is present in most welders. Despite this, some welding machines fail to have this feature, causing them to catch fire and causing damage to sensitive parts.

Welding machines use thermocouples to monitor their internal temperatures. When the thermocouple reaches the critical temperature, a signal is sent to the circuit that detects thermal overload, resulting in the power being shut off.

The power plug cannot be removed from the welder when the thermal overload mode is active; do not remove the power plug from the welder. The cooling fans will shut off, but they should continue to run to help push out heat from the system.

Consistently violating the duty cycle will reduce the system’s lifespan regardless of the manufacturer’s claims. At excessive temperatures, insulation and components inside the equipment deteriorate, ultimately leading to failure.

It is, therefore, important not to constantly exceed duty cycle limits. A welder’s printed circuit sheet contains thousands of tiny components, and it is possible to fry a capacitor or resistor if you push it to the limits.

Additionally, there are connections between many components that are the size of a human hair that allow them to work. Overheating these will damage them, as they are sensitive devices.


You Can Prevent Accidental Fires

If the machine exceeds its maximum operating temperature, a thermal overload safeguard will be initiated automatically. When the protection is activated, it immediately shuts down. You can perform welds with greater efficiency and productivity when taking these precautions. As a result, well-welded joints are produced and profitability is maximized.

Welding Priorities

With a firm understanding of the welding systems duty cycle, it will be possible for you to plan accordingly, for example, knowing when to stop welding so that you can meet all your goals. The welding time is significantly lowered, giving you more time to spend on essential things.


Overheating can cause the machine to catch fire. It is possible that the protection against thermal overload hasn’t been activated when the duty cycle has been compromised. There is a risk of serious damage and even death for the operator if this occurs.

The Welding Process Is Constantly Interrupted

Especially when a weld is essential, and you have limited time, frequent cuts can affect your capacity to meet goals, which may result in downtime. Low-duty machines are notorious for this problem.

The Welds Are of Poor Quality

A machine that tends to reach its duty cycle limit after a relatively short period will cause the quality of the welding to decrease. If you start to notice your welds are getting worse, this could be the reason.


Almost all welders want a machine that enhances their welding work and lasts forever. You should always be aware of the duty cycle of your machine to avoid mishaps, malfunctions, and failures. Make sure your machines are regularly checked and maintained so that you can detect problems as early as possible.

Alternatively, you can call an engineer to come in and carry out an assessment. The professionals will take care of repairs and replacements for you. Duty cycle welding is important, so ensure you are familiar with how it works before you go ahead and try it.

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