Can you Run a Stick Welder on a Generator? -What size Needed to Run Welder?

Stick welding is one of the most used welding techniques for arc welding. A Stick welder uses a solid metal electrode (stick) and electric current to join metal pieces together. This welding technique is relatively simple to learn, and its versatility has contributed to its popularity, especially for beginners.

One of the first questions welders ask before considering purchasing is a stick welding machine is: ”can you run a stick welder on a generator?”

The correct answer is not always a straight yes.

Here’s why

While you can use an inverter stick welder with a generator and operate it at the same level as the main power supply, not all machines are equipped to have the protection needed against inconsistent generator power supply.

The stick welder is connected to a power source to create the electric current (either DC or AC) that forms an arc between your metals. While it is always a good idea to use mains power to run your machine, running a welder off a generator offers a couple of advantages to users who need to use the machine out in the field or worksites where it is impossible to access electricity.

However, generator power is often characterized by sudden peaks in voltage (voltage spikes) and voltage surges, and this is the main reason it is often referred to as “dirty power”. This occurs due to several reasons, including;

  • Poor quality generators: The market is flooded with cheap and poor quality generators that are unsuitable for running inverter-based welding machines. Using such generators might lead to unacceptable voltage fluctuations.
  • Poor maintenance: Lack of proper maintenance is likely to affect generator performance to a great extent
  • Fluctuations during start up/shut down: The voltage is also likely to fluctuate or spike when starting off or stopping the engine.
  • Interruption in the fuel supply: When the fuel supply is cut short or there some hiccups, the engine will generally run irregularly, leading to power fluctuations
  • Overloading the generator: It is a no-brainer that an over-loaded generator will work extra hard to maintain a constant power supply. While this happens, it might cause the voltage to fluctuate or spike to severe levels. Running the welder and other machines, e.g., a grinder or cut-off tool, off the same generator can cause power fluctuations, especially if the generator is small-sized.

Tips for generator use with a stick welder safely

Determining the right generator to use with your stick welder can be a tricky process, and there are important considerations you need to keep in mind to ensure both the welder and generator perform to their full capacities, as highlighted below.

What size generator for welder?

The first thing you’ll need to do is to determine the correct size of the generator needed to run the welder safely. Consider the rated output of your generator to determine if it is compatible with your stick welder. Most manufacturers provide the total watts required by the welder, which is quite helpful in determining the minimum generator size recommended.

The minimum recommended size is the smallest generator you can use without risking voltage spikes or fluctuations, but it may not be the ideal size to achieve optimal performance from the welder. Although the welder can run to some extent using a smaller-sized generator, using the ideal size will help minimize chances of power problems while allowing you to achieve maximum output from your welder. An under-sized generator is not recommended for the following reasons;

  1. The generator will be forced to work extra hard to meet the welder’s demands, which might increase the risk of serious voltage fluctuations that could damage your equipment severely.
  2. Using a small generator will greatly reduce your output and that of the welder, and it might lender the machine literally useless.
  3. You might need to use the generator to run other power tools, which might overload your generator further.

Getting a larger generator might be costly at first, but it will get the job done without struggling. It will also minimize the risk of damaging your equipment which might cost you more in the long run. As a rule of thumb, the ideal generator for a stick welder or any other welding machine should have a higher output than the requirement of the welder to safeguard against overloading, fluctuations, and tripping.

Watt requirements for the stick welder

The next consideration you’ll need to keep in mind is the maximum number of watts the welder needs to operate efficiently. You can easily get this data from the product specs in the user manual or the company’s website. The information provided by the manufacturer is the minimum wattage required in order to run. For instance, if your welder is rated for 5000 watts, you’ll need to get a generator that can at least output 5000 watts and possibly more.

Quality of the generator

When choosing a generator for welder, ensure it has a low Total Harmonic Distortion (THD) output to ensure consistent power production. A generator with a reasonable THD rating will produce a fairly “clean” power making it suitable for running a stick welder and inverter machines in general. Generators with high THD ratings, i.e., 6% and above, are not ideal for running welders.

Extra loads

Other than the number of watts that the welder will draw, you’ll also want to consider whether there are other power devices that will be running off the generator at the same time. For instance, if you intend to run a grinder or any other power tool of the same generator, you’ll need to add their power consumption in your calculations and increase the size of the generator accordingly.

The Bottom Line

The inverter technology has made it possible to run various power equipment, including welders off a generator. The technology helps generators create clean and stable power output that is ideal for stick welder and inverter welders in general. When choosing a generator for your welder, it is always a good idea to get one that’s capable of delivering at least 1.5 times more watts than the input voltage that your welder needs for best results.

This also minimizes power supply problems that might lead to costly damages or cause the welder to shut down sporadically. The bottom line is; ensure to check the wattage of your welder when choosing a generator.

Leave a Comment