Generator for Welder | Which One is Right for You?

Last Updated on April 30, 2021 by Antonio H. Johnson

Besides using the mainline power, welders can also use generator welding. Although it’s recommended to use the mainline, we can also use a generator for welding if we can choose the correct equipment and the proper generator. Generator for a welder can allow them to work in the field. Generators allow good portability for welders. The generators and the welding machines today are very powerful and also quite user-friendly. These allow welders to work in more remote locations and make it easier for them to work effectively.

This article will try to look at the good sides and the limitations of using generators for welding. We will observe how to choose the perfect generator for you, the things to consider while buying a generator, and so on. So, let’s get started.

Inverter welding machines

These welding machines can be used using generators, so we need to know about them before discussing the generator for the welder.

Inverter welding machines are welding machines that can be used by plugging into a generator. Inverter welding machines convert the AC to DC. They invert the DC current into a step-down transformer, which provides the required current for welding.

Comparison of generator power and mainline power

Ideally, the mainline power is the best power source for welding. But with the proper generators and the right inverter welding machine, you can work smoothly and without problems.

Mainline power offers an excellent power draw. Welding machines can function under full capability when plugged into the mainline. There is no potential risk of damaging the welding machine’s equipment if plugged into the mainline. There is no primary need for inverter welding machines for welding using mainline power.

If we are to use generators for welding, we have to ensure that we have chosen the perfect generator based on our usage. We have to provide an excellent inverter welding machine. Without using the proper generator, we can damage our equipment.

Small generators might be portable and easy to handle, but they seldom damage the welding equipment. Due to inconsistent power draw from generators, sometimes welding machines can be damaged. A proper generator for welder offers excellent mobility. It will help you weld in places where it is impossible to gain access to mainline power.

Make sure you read this article thoroughly to know what type of generator you should use.

Understanding the values of a generator for welding

The output power of a generator will be expressed in Watts. Remember a simple formula,

Watts= Amperes x Volts

For example, a generator marked with 5000 Watts can provide 25 Ampere at 200 Volts or 20 Ampere at 250 Volts.

If the output is written using kVa (kilovolt-ampere), you can convert it to watts by multiplying by 800. Therefore,

Watts= kVa x 800

For example, a generator marked with 3 kVa can provide 2400 Watts.

There will be two output data given in a generator. One indicates the Surge Watt, and the other shows Running Watt. When a generator starts, it provides about 25-30% more power than the running Watt; it is known as the Surge Watt or start-up watt.

Before purchasing any generator, make sure to check the output values. The running Watt and surge watt values positions vary for the manufacturer. Check which value represents the running watt value and which one represents the surge watt value.

In this way, through consideration, you need to select your generator for welding carefully.

Knowing your watt requirement as a welder

One of your primary tasks is to understand how many watts you need to draw from the generator as a welder. What will be your task and how much power is required to run your equipment smoothly for that task is crucial for you to understand.

It would be best to give a clear description of your watt requirements to the person who will hire you. You should know the minimum watt requirement of your equipment to make it function at 100% capability.

Understanding the power requirement of your welding equipment

  • The volt requirement: You can find generators of 120V or 240V. The welding machines, however, sometimes require 110, 115, or 230 volts. To understand the correct volt requirement, look for the U₁ manufacturer number on the data table. This volt is the volt the manufacturer used to rate the welding machine.
  • The ampere requirement:  On the manual of the welding machine, find the I1max  number. That number indicates the maximum current draw of your welding machine. It might be marked as “surge” or “inrush “current draw.
  • The watt requirement: After finding out the volt and the ampere requirement, multiply both of these values. The value you will obtain will be the maximum watt requirement of your welding machine. For example, if your welding machine’s watt requirement is 3876W, it is recommended to use a generator of 4000W.

In this way, you can find out what type of generator you require for your welding equipment. Be careful, make sure you meet the requirements or have a very high risk of damaging your machine.

The effect of high altitude on generators

Suppose we go high above the surface; if the altitude increases, the density of air decreases. As the density of air decreases, the power of the generator also starts to decrease. It decreases about 3.5% power with the increase of every 1000 feet altitude.

This is an important thing to consider if you’re looking to weld in high places using a generator.

Types of welders and their power requirements

Based on the power sources used, welders can be divided into two categories. Their power requirements also vary. Let’s describe them below:

  • Conventional Transformer-based Welders: These machines contain massive transformers made of aluminum and copper. They act as step-down transformers, which convert high voltage AC to low voltage/high ampere DC. These devices are very well suited for any and can handle the dirty power of generators with ease. Conventional welders work excellently with different generators.
  • Inverter Style Welders: Inverter welding machines weigh half of the conventional welding machines. They use smaller transformers than conventional ones. They provide a more stable output because of the high voltage storing capacitors in them. Generators produce unpredictable ups and downs in voltage values; this is known as Dirty Power. It can cause damage to the inverter welding machines.

Older inverter welding machines that use “MOSFET Technology” are impacted dramatically by this.

Newer inverter welding machines using “IGBT” can handle the impacts better.

Types of generators

There are mainly two types of generators based on power draw. They are as follows:

  • Traditional Generators: These types of generators generate power in one step. Rotating the alternator creates energy. But sometimes, when the RPM fluctuates, there can be fluctuations in power as well. This distortion is very harmful to inverter welding machines. It would be best if you didn’t use these generators for inverter welding machines.
  • Inverter Generators: The same tech used in inverter welding machines is used in these generators. Inverter generators allow very stable power outputs and cause fewer fluctuations. This generator is best for welding.
Generator for Welder

Frequently Asked Questions

1. Can a welding machine be run using a generator?

Answer: Yes, but you should use the proper generator of proper watt output.

2. How many watts do I need for my welding machine?

Answer: Multiply the I1max   and U value of your welding machine. You will find the watt requirement.

3. What is the best welder generator?

Answer: The generators vary with the demand of the welders. However, the Miller Bobcat 250 offers the best value for the price.

4. Which size generator is ideal for 120V welding?

Answer: A generator of 5000 watts is perfect for welders operating at 120V.

5. Is it possible to run a welding machine using solar power?

Answer: Theoretically, it might be possible. But the quality of the welds will be very cheap.


So, through our article, we have taught how to pick the correct generator for the welder. We’ve taken you through how to figure out your welding machine’s watt requirement, which welding device you should use under what circumstances.

Welding using generators is quite effective in the modern age. Welders have been able to work in more isolated and complicated positions. With time generators are becoming smaller and more effective. Thus, with the proper generator, you can hope to become a high demanding welder.

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