What Size Breaker For A Welder?

If you are a welder, then you know how hectic it is to use a low-powered breaker. The wiring of the device should be strong enough to support the device’s current requirements. Welding needs substantial wiring since it consumes a large amount of current. Therefore, you will have to know “what size breaker for welder” for your welder. 

More so, you have to understand the amperage required to operate the MIG welder smoothly. I hope that this article will help you know the right size circuit breaker you need for a welder. As said, these devices are powerful and are associated with taking a large number of volts. 

What size breaker you require for the welder? 

We can use some factors to determine the size of the circuit breaker for a welder. The amount of current needed by devices is the top way to detect the right size breaker for your welder quickly. For example, a tool that needs 27 amps will require a circuit breaker of 30 amps.

Furthermore, the gauge of the wire used in wiring a circuit should also have to support a specific current. The supported wind should be fully allowed by the breaker. For instance, a 12-gauge wire will require a circuit breaker with 20 amps. 

Welders need a breaker size of not less than 220V, which requires at least 30 to 40 amps breaker. For smaller welders, 115v with a 20 to 30 amp breaker is just enough. For the three-phase, you will require a breaker with a maximum amp of 50 based on its voltage.

Depending on the outlets you require, a smaller 115v device will encourage a standard home three-prong outlet. Also, using a 30 amp or 220v welder plug, there is a need to have a 3-prong heavy-duty or 4-prong outlet. 

Welder circuits and conductor sizes

Many conductor sizes that have insulation also accommodate several amounts of currents. For that case, an eight-gauge wire can comfortably sustain at least a 40-amp current. On the other hand, a six-gauge wire is suitable for 50 amps current.

Additionally, it is advisable to size the welder circuits and wiring depending on your welder’s requirement input current. Therefore, a 240v, 40 to 50 amps input welder will require a 50-amp circuit breaker and 6-gauge wiring. 

Furthermore, welders that use less than 30 amps can be compatible with a circuit breaker of 30 amps and a 10-gauge wire. So, it is good to know the type of job you plan to use the welder for.

Other factors in determining what size breaker for a welder

Knowing the number of amps also determines the size of the circuit breaker for your welder. Remember, these factors are close to each, separating them can be challenging. Therefore, you can only determine the number of amps depending on the job you want to work on with the welder.

Below are some of the primary questions that you can employ in determining the size circuit breaker for a welder;

  1. The thickness of the material to weld

If you intend to weld heavy metals, then you need a welder with a 220v circuit breaker. The reason behind this statement is that such a welder can enable you to penetrate through the material with the aid of high temperature. This welder can appropriate for welding ½-inch metals. 

However, if you will be handling ¼-inch thick metals, you need just a small welder with 110 volts. This will allow you to take metals that are lighter comfortably. 

  1. Welder application

If you intend to operate production for a small enterprise or use the welder within the farm, you will have to use a 220v welder. On the other hand, if you plan to run the welder for high-end and more efficient production, a 3-phase welder can make a perfect choice for such situations. This will provide you with 300 to 600 amps or more. 

Remember, a 3-phase welder will only run under a 3-phase power. More so, most homes operate a 200-amp welder. Therefore you will require converted wiring to run such a welder. 

However, if you intend to utilize the device on small jobs, a 110v welder, 30 amps is enough for you. You can use the welder around your home or small shop since the unit will provide not less than amps. 

  1. Power 

This is another consideration you should be keen on. If your welding job is within the garage, 115 volts will hinder you from what you can achieve. Smaller farms or shops require 220v welders to allow you to get a machine with higher amperage. Moreover, if you operate a small-medium size enterprise, then a 3 phase power can be suitable for working with bigger welders. 

  1. Duty cycle

This is another critical consideration that can help you determine the circuit breaker’s size for a welder. It usually involves the exact time that your welder can clock at a particular amp. Generally, the duty cycle is displayed in percentages. 

For example, if your welder has 30% at 90 amps-duty cycles, it means that the device can continuously weld for not less than 3 minutes. Such a welder requires 7 minutes to rest before the next welding. 

On the other hand, if the welder features a 20-percent duty cycle, amps will be 90 and allow you to weld for less than 2 minutes and give it 8 minutes for cooling. 

Frequently asked questions

What is the benefit of welders with higher amperage?

These welders provide you with many advantages like; welding thicker materials, deeper penetration, and consistent and cleaner welds.

How can I determine the size breaker for a welder based on the outlets?

Depending on the outlets you require, a smaller 115v device will encourage a standard home three-prong outlet. Also, using a 30 amp or 220v welder plug, there is a need to have a 3-prong heavy-duty or 4-prong outlet. 


From the above discussion, it is clear that the type of job you plan to work on can determine the circuit breaker’s size. For instance, a 30-amp circuit breaker is suitable for a 110-volt welder. On the other hand, a 40-circuit breaker is appropriate for bigger welders like a 220-volt welder. Hopefully, this article sheds some light on what size breaker for a welder.

Leave a Comment