What Size Generator Do I Need to Run a Welder?

If you live in an area with frequent power outages or if you want to get your welding job done while away from a wall power outlet, you’d need to find an alternative way to power your electric welding machine.

The best and the most reliable solution for this problem is to use a portable generator.

In case you’ve never had experience using a portable generator to run a welder, you might find yourself unsure whether a specific model is able to run an electric welder of your choice.

The main reason for you to approach the task of choosing the best generator for a welder seriously is that not every portable generator can provide enough peak power for welding to operate normally. You’d need to get yourself a portable power generator that can produce enough starting Watts to let you start up an electric welding device.

Even if your generator has a decent number of running Watts, you’d still need to keep in mind the starting Watts should be greater or equal to those required by a specific welding device.

In this article, we’re going to find out how many Watts are required to successfully start and run a 220V and 110V welder.

Can I run a 220V welder off a generator?

The quick answer is yes, this welder can be powered by a portable generator. Make sure to get a generator that can output 220 or 240V. Most generators you can find on the US market only output 120V.

The most important part, however, is to choose a generator that is powerful enough to give your welder an initial boost and then, continue running it.

You may also want to power additional electric devices from the same generator, so, it is best to get the one with some extra power.

Besides the wattage requirements, the generator for the welder needs to provide you with at least 4 hours of continuous running. This will allow you to complete your welding projects without the need to refuel that generator constantly.

Keep in mind that the power generator’s engine needs periodic maintenance and oil change to continue running on a regular basis. Therefore, it is best to choose a portable generator with long service intervals.

Can I run a 110V welder off a generator?

Absolutely yes. Both 240 and 120V portable generators are able to run a 110V electric welder. Most 240V generators can also power 120V devices, so, it is hard to find one that will not work with your welder. Just make sure your generator can provide enough wattage for a welder that you own.

What Size Generator Do I Need to Run a Welder?

There are 2 main specifications that will help you decide on the generator size that you need for your welder: voltage and wattage. Now, the voltage part is easy, if you’re using a 110V welder you can either get a 240V or 120V portable generator. They both will run your welder just fine. If, however, you’re using a 220V welder, make sure to run it from a 220 or 240V generator.

The wattage required for a welder

What about wattage? This part is a bit less straightforward, but, here is the simple calculation that you need to perform to find out how many Watts your generator must output if you want to run your welder.

W = V x A (wher W stands for Watts, V – for Volts, and A – for Amperes)

Most likely you already know how many Volts your welder operates on. So you just need to find your welder’s input current in the owner’s manual or from the welding equipment dealer.

Once you know how many input amperes (A) your welder consumes, you just need to multiply it by the input voltage of that welder and you’ll get the number of Watts it will draw.

For example, let’s say we have a 110V welder that requires 40A (amperes) input current. Then with the above equation, we have 110 x 40 = 4,400W, or 4,400 Watts required from your generator. Best if you get a 5,000W generator so you can run additional equipment too.

Power socket amperage

There is one more thing. When you know your welder’s wattage and you know which generator can produce this amount of Watts, you also need to make sure your generator has an outlet that can withstand greater or equal amperes than your welder requires.

For instance, most generators come with 30A and 50A power outlets. In the scenario of using this generator for a welder that requires a 40A input current, you need to make sure your generator has a 50A power outlet and you always plug your welder into that outlet. The good news is when you’ve calculated the wattage for your welder and found a suitable generator, in most cases, it will have at least one outlet that can offer enough input current for your welder to run smoothly.

For example, a 7,000 Watts portable generator will always have a 50A outlet so you can run your 40-50A welder on it.

Do not mess welder’s input current and output Amps. You will likely have a 180 Amps welder that only requires a 40A input current.

Will a 3,000-Watt generator run a welder?

Such a small generator can run a welder, but, the welder must also be small enough. More specifically, you can run a welder with input current requirements from 13 to 25A.

Will a 7,000-Watt generator run a welder?

This size of generator can already run a medium-sized welder that requires 31 to 63A input current. In most households, you will not want a bigger generator for hobbyist welding projects. This generator, though, might not be enough for commercial welding tasks with a big welding machine. In this case, consider a 10,000W or even 12,500W portable generator.

What size generator do I need to run a 180-amp welder?

It depends on the specific welder input current draw. Most 180 Amps welders on the market require 30 to 45A input current. In this case, you should be fine running those from a 5,000W to 7,000W generator.

What size generator do I need to run a Lincoln 225 welder?

The Lincoln 225 ARC welder is a wonderful and expensive device that requires quite some power from your portable generator. This welder is offered in 2 variations that require an input current of 50A and 60A. Since this welder runs on 230V, you’re going to need a big power generator of 11,500W or 13,800W respectively (depending on if your Lincoln 225 is a 50A or 60A model).

Be sure to get a generator with running Watts of 11,500 or 13,800, while its starting Watts will be even higher.

What size generator do I need to run a 220-V welder?

Similar to a 110V welder, the first step is to find out the input current of a specific welder. Then, when you know the amperage, you can easily calculate the minimum power required from your generator by multiplying the number of amperes by the number of volts of your electric welder.

For instance, let’s say your 220V welder requires 45 amperes input current. Then, when multiplying 45 by 220 yields 9,900 running Watts required from your generator. While you can’t find 9,000W generators on the market, you can easily find 10,000W.