How to parallel generators? Ultimate Guide

Paralleling generators, a technique often employed when a single generator’s power output is insufficient involves connecting two generators in tandem to generate a higher power output. This method is particularly beneficial in scenarios where power demand exceeds the capacity of a single generator, such as outdoor events, disaster recovery operations, or powering large homes during outages.

This article will provide a comprehensive guide on how to parallel generators, including step-by-step instructions, and tips for choosing suitable generators for paralleling.

How To Parallel Generators

What Does It Mean to Parallel Generators?

Paralleling generators refer to the action of connecting two or more power sources together to manage a supplied load more efficiently. This process involves synchronizing multiple generators’ phases, frequencies, and voltage outputs, allowing them to operate in harmony and share the power load.

The science behind it includes the utilization of a paralleling switchgear system. This system ensures all generators are in phase, have the same frequency, and are generating the same voltage. Once these conditions are met, the generators can safely be connected in parallel.

The benefits of paralleling generators are manifold. Firstly, it enhances reliability by providing a backup power source if one generator fails. Secondly, it allows for greater flexibility, as additional generators can be added to meet increased power demand. Lastly, it promotes fuel efficiency, as generators can be brought online as needed, reducing unnecessary power generation and saving resources.

When Should You Parallel Generators?

Paralleling generators is particularly beneficial in scenarios where a large amount of power is needed, such as large events, during power outages, or at construction sites.

Large events, such as concerts or festivals, often require a high power demand that a single generator may not be able to fulfill. By paralleling generators, organizers can ensure that the event runs smoothly without any power interruptions.

Similarly, during power outages, especially in critical facilities like hospitals or data centers, paralleling generators can provide a reliable power source. It allows for continuous operation while utility power is being restored, preventing the risk of significant equipment failure due to a power outage.

Construction sites also frequently benefit from paralleling generators. These sites often experience varying power demands throughout the project. By using multiple generators in parallel, constructors can scale up or down the power supply as needed, promoting efficiency and saving energy.

Not paralleling generators when needed can pose significant risks. It can lead to a single generator being overloaded, causing potential damage to the equipment. Moreover, relying on a single generator increases the risk of complete power failure, leading to potential operational disruptions and financial losses. Therefore, paralleling generators should be considered in situations where a stable and flexible power supply is crucial.

Types of Generators That Can Be Paralleled

Various types of generators can be paralleled to meet the power demand.

  • Inverter Generators: Inverter generators are particularly suited for paralleling due to their advanced technology. They produce consistent power with less voltage fluctuation, making them ideal for sensitive electronics. Two or more inverter generators can be connected together to produce a combined output.

Have A Look At How Does an Inverter Generator Work

  • Conventional Generators: Although less common, conventional generators can also be paralleled. This requires a more complex set-up and careful monitoring as they produce high-voltage power. It’s important to make sure the generators are of the same make and model to prevent power phase discrepancies.
  • Brand-specific considerations: Some brands have specifically designed their generators for paralleling. They come with built-in paralleling capabilities and special kits to make the process easier. Always check with the manufacturer before attempting to parallel generators of different brands to ensure compatibility and safety.

Equipment Needed for Paralleling

Paralleling generators require specific equipment to ensure a safe and effective setup.

Parallel Kits:

Parallel kits are designed to safely connect two or more generators without the risk of backfeeding. They include outlets for your appliances and circuit breakers to prevent overload.

Parallel Kits:


Paralleling cables are used to connect the generators together. It’s imperative to use high-quality cables that can handle the power output of your generators without overheating.


Other Accessories:

Additional equipment may include grounding rods, connectors, and surge protectors. Grounding rods can enhance safety by reducing the risk of electrical shock, while connectors and surge protectors ensure a stable connection and protect your equipment from sudden power surges. Always consult with a professional or the generator’s manufacturer for specific recommendations concerning additional accessories.

Step-by-Step Guide to Paralleling Generators

Safety Precautions

Before you begin, ensure that you and everyone involved in the process are wearing the proper safety equipment. This may include safety glasses, gloves, and sturdy footwear. Keep the area clear of any flammable materials and ensure that the generators are situated on a stable, dry surface away from any water sources.

Setting Up the Generators

Start by positioning your generators at least 6 feet apart to allow for proper ventilation and to reduce the risk of overheating. Make sure the generators’ switches are in the ‘OFF’ position and that they are not connected to any appliances or electrical loads.

Connecting the Parallel Kit

Connect the parallel kit to each generator using the provided cables. Ensure that the connections are secure, and the cables are not showing any signs of damage or wear. Remember to connect the grounding rods to each generator if required.

Testing the Connection

Before starting the generators, test the connection to ensure that it’s safe and secure. You can do this by using a multimeter to verify the correct voltage and phase alignment.

Starting the Generators

Now, you can start the generators. Turn one generator on and let it run for a few minutes. Then, start the second generator. The generators should be running at the same speed and producing the same voltage.

Monitoring and Adjustments

Once the generators are running, monitor the power output and make any necessary adjustments to ensure that the load is being shared equally. If the generators are not synchronized or there are any issues, shut them off immediately and resolve the problem before attempting to parallel again. Always refer to the generator’s user manual or consult with a professional if you’re unsure.

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Tips for choosing suitable generators for paralleling

When selecting generators to parallel, it’s important to make sure that they are compatible with each other. You should look for generators with similar frame sizes and power ratings as well as ones that use the same type of fuel like gasoline or diesel. Make sure to check the warranty conditions too so you can get repairs and replacements if needed.

It is also wise to consider the environment when selecting generators. Alternative fuel sources, like natural gas or propane, are more efficient than gasoline and diesel and create less emissions.

Finally, make sure to get enough outlets for all your equipment. If you need more power output than a single generator can provide, paralleling two or more units will be necessary. Choosing the right generators is

Common Mistakes to Avoid

When paralleling generators, there are several common mistakes to avoid:

  • Incorrect Setup – Always ensure that the setup is correct before starting the generators. An improper setup can cause the generators to fail, leading to potential damage or even a risk to your safety.
  • Using Incompatible Generators – Not all generators are designed to run in parallel. Attempting to connect incompatible generators can result in damage to both the generators and any connected appliances. Always refer to your generator’s user manual to confirm whether it can be used in a parallel setup.
  • Safety Hazards – Safety should be your primary concern when working with generators. Always ensure that generators are placed on stable, dry ground, away from water sources or flammable materials. Furthermore, never attempt to refuel a generator while it is running as this can lead to a fire risk. Practice routine maintenance and inspections to avoid potential hazards and ensure your generator operates safely and efficiently

Frequently Asked Questions

Typically, it’s not recommended to parallel generators of different brands. Each brand and model has its own specifications and design, and these differences can cause operational problems when attempting to run them in parallel. Always refer to your generator’s user manual or consult with a professional before paralleling generators.

The number of generators that can be paralleled depends on the specific model of the generators. Some models allow for only two generators to be paralleled, while others can accommodate three or more. Again, always refer to your generator’s user manual or consult with a professional for precise information.

Yes, it’s safe to parallel generators when done correctly. However, if not done correctly, it can lead to operational issues and safety hazards. Always ensure proper setup, use compatible generators, and maintain safety protocols, as outlined in the previous sections of this guide, to ensure safe and efficient operation.


In conclusion, the paralleling of generators is a viable method to increase power capacity, maintain reliability, and enable load sharing. However, it’s critical to keep in mind that not all generators are designed to be paralleled. Always refer to the specific model’s user manual or consider professional consultation before initiating the process. Remember, safety is paramount; generators should be placed on stable, dry ground, away from water sources or flammable materials, and never be refueled while running.

Paralleling different brands of generators is typically discouraged due to design and specification differences. The number of generators that can be paralleled is contingent on the particular model. When paralleling is done correctly, it’s safe and can improve operational efficiency.

In light of these points, it’s recommended to thoroughly explore your generators’ abilities and limitations before deciding to parallel. By following the guidelines provided in this document, you can safely and effectively run generators in parallel to meet your power needs.

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