What Size Generator to Run 140 Amp Welder?

Welding isn’t always confined to your garage or shops. You might need to pick up a welder and dive into the sanity or chaos of construction sites or other places. Where do you get power from to run your welder?

The answer is obvious, from a generator. But, do you get enough power from just any generator? This answer is also obvious, no, you don’t. For running a 140-amp welder, you need a generator having a minimum running wattage of 5000 watts.

Let’s get into more detail and find out what size generator to run a 140-amp welder?

What Determines the Size of the Generator for Welding?

Two simple things, though many find them difficult, determine what will be the size of a generator to run a welder. First, you need to check the power type of the welder.

Some units run on 120 volts and some others run on 240 volts. Certain welders can run on both voltages. You just need to determine the wattage of the welding unit to find out the right sized generator for the welder.

The general rule is to multiply input voltage and output amperage to find out the wattage of the welding unit. Say you have a welder with an input voltage of 240 volts and an output current of 24 amps. It will give you a maximum wattage of 5760 watts.

This figure will be the running watt of the generator you are going to buy. But this is not all you need to take care of. Let’s move on.

What to Consider When Choosing a Generator to Run a 140 amp Welder?

Other than just the wattage, you need to consider some other crucial factors as well. We will take a quick look at some of those factors here.

Low THD

Unlike AC power we use at home; traditional generators produce DC power that directly goes into appliances like welders. In some cases, the produced power isn’t streamlined.

So, it causes a deviation in the usual supply or the power, which is known as Harmonic Distortion. If the total harmonic distortion of a generator is higher than 6%, the generator is considered to produce dirty power.

Make sure the total harmonic distortion value is less than 5-6% to get a good generator for welders.

Visible Fuel Gauge

As soon as the fuel of any generator goes under a certain level, output power drops drastically. It can affect the performance of your welder. So, it is crucial to ensure consistent fuel levels all the way through.

A generator with a visible fuel gauge will help you monitor and adjust the fuel level all the time. This way, you won’t impose any risk on your generator or welder.

Proper Safety Margin

Once you have determined the required running watts of a generator, consider keeping at least a 30% safety margin. For example, if your welder needs a generator with a running wattage of 5000 watts, you need to take a generator of 6500 watts so that it starts smoothly.

DuroMax XP5500EH Dual Fuel Portable Generator can be a good choice if your welder fits it.

The altitude of Your Workplace

In case you don’t know about it, generators tend to lose about 3.5% of their power for every 1000 ft of altitude. So, if you are working somewhere higher than usual, remember to take a generator with more power.

Portability

As you will need to weld in many different places depending on your jobs, you need a generator that can be taken to the job site quite easily. But portability comes in very handy when it comes to moving the generator from one place to another within the job site.

A portable generator is a must if you don’t want the hassle of lifting the heavy machine over and over again.

Generator Size Chart to Run 140 amp Welder

Though you will be running a 140 amp welder, this detailed chart of what should be the size of the generator based on your welder will help you every now and then.

This is just a basic idea. But it is a safe idea too. You can experiment a bit but don’t go too far from expert opinions.

What Is the Best Generator to Run 140 Amp Welder?

Giving a direct answer to this question is quite difficult. Depending on the requirements of the welder and your personal choice, you can go for many different brands and sizes.

But according to many experts in the industry, the Westinghouse WGen6000 Portable Generator with a running wattage of 6000 watts and surge wattage of 7500 watts will be the best solution to run your 140 amp welders.

You will get a 6.6-gallon fuel tank on this model to provide power to your welder for about 13 hours. A fuel gauge will make it easier for you to maintain the fuel level.

It comes in a wheelbarrow design for easy carrying.

Tips for Running Welder with A Generator

Here are some pro tips from our side to make your welding jobs easier.

• Always search for the welder’s specifications like max voltage and amperage to determine the right wattage of the welder. It is crucial to find the right generator for it.
• Keep at least 30% of the safety margin for smooth operation.
• While you turn the generator on or off, never keep the welder plugged in.
• Don’t run the generator in fuel-saving mode. It will affect the power output.
• Always maintain a safe fuel level to ensure consistent power delivery.
• Don’t run a lot of accessories on the generator.

Final Thoughts

Plugging the welder into the generator and starting welding right away is easy. The difficult part is to decide what size generator to run a 140 amp welder? We have tried to give a brief overview of how you calculate these things.

Please be extra careful while choosing the right generator. If you go too offset from the standard, you will be risking your life in the first place. Stick to the standard and keep welding safe.