Portable Generator Transfer Switch (+Installation Guide)

Portable generator transfer switches are an important part of any emergency power plan.

They allow you to temporarily connect your home’s main electrical feed from the utility company with a portable generator without switching over to it permanently.

A portable generator transfer switch kit is a handy tool during a power outage.

It allows you to easily connect your generator to your home’s electrical system and run your appliances without having to worry about back feeding the grid.

This article will go through the process of adding a transfer switch, connecting appliances, and avoiding common problems when using a portable generator for an extended time.

Most installations can be completed in four hours or less if you are handy with simple tools.

Advantages of Using Generator Transfer Switch

There are many advantages of transfer switches as:

Peace of mind

Knowing that you have a backup plan in case of an emergency.

Transferring back to the utility company is automatic once the service has been restored, so you never have to remember to do it.

Increased reliability

With two sources of power, you’re less likely to experience an outage.

This provides redundancy for keeping the lights on during emergencies like storms or hurricanes that knock out power for days at a time.

Added safety

A transfer switch can help prevent dangerous back feeds into the grid.

Transferring between utilities can help keep voltage stable and prevent surges from damaging connected appliances.

Lower energy costs

On electricity bills, you can save money by automatically switching to your generator when there is an outage.

It can save money using less fuel if you run the generator only when necessary.

Convenience and ease of use

in most cases, a transfer switch can be installed with minimal effort.

Once it is properly sized for your power needs, all you need to do is plug in your appliances.

How to Choose the Best Transfer Switch for Generators?

If you own a generator and use it quite often, it is important to purchase a transfer switch for your machine.

This will allow it to be connected directly and safely and protect both the machine and anyone using it.

The following gives you five guidelines that should help you choose the best transfer switch for generators.

1. Selecting the Type of Transfer switch

An automatic transfer switch is usually the best choice for a generator as it provides guaranteed power to appliances and electrical devices. I

t also helps prevent overloads that could occur if you connect the generator directly.

This transfer switch does not need to be reset or turned off when switching from utility power back to the generator.

Manual switches will need to be turned off when changing between power sources.

2. Selecting the Rated Amperage of the Transfer Switch

The transfer switch you buy should match the amperage of your generator’s outlet, typically either a 30 amp or 50 amp – 50 amp transfer switch for a portable generator or a 30 amp transfer switch for a portable generator.

Buying this way helps protect the generator and the appliances it is powering.

It also prevents overloads and costly repairs that could occur in the future.

3. Selecting the Size of the Transfer Switch

If possible, you should size your generator’s output to match the rated amperage of the transfer switch.

This way, you are not introducing voltage problems to the system, which may cause damage to appliances over time.

This directly relates to safety and potential problems that can arise from overloads.

4. Selecting the Type of Load Transfer Switch

The type of load transfer switch will depend on what you use it for and how often you need to connect and disconnect between power sources.

There are two primary types: Vertical style switches offer a better fit in some spaces, while horizontal ones are better for larger areas.

It is important to choose the style that best fits your generator and its location.

The style you select should be based on your preference, plus what will fit in the space where it will be located.

There are three styles of transfer switches that are typically available: Vertical style switches offer a better fit in some spaces, while horizontal ones are better for larger areas.

It is important to choose the style that best fits your generator and its location.

Best Portable Generator Transfer Switch Kits/Units

For up to 7500 watts Generators

Reliance Controls 31406CRK 30 Amp 97500W

reliance controls 31406crk 30amp
Reliance Controls 31406CRK 30amp

This kit has a starting wattage of 9500 and a running wattage of 7500. Again this means it will work with virtually any generator on the market.

This generator transfer switch kit is perfect for smaller homes, apartments, or cabins where you can shut down one circuit at a time.

It comes with a remote wireless power inlet box (PB30).

As you can see, the price is really low, but the quality of this product is excellent, and it allows you to install a generator in your home without any additional costs.

The installation is pretty straightforward and can be done by most homeowners with average skills and knowledge in electrical work.

This usually means it takes around 1-2 hours to complete the installation process.

It comes with the 10 feet long power cord. This means it is easy to install even in areas where this cable length might not always perfectly match your needs.

The kit comes with wire nuts and the male plug for 20 amp generator outlets.

It has an amperage of 30 amps which makes it ideal.

This transfer switch is from Reliance Controls Corporation and comes with a 5-year limited warranty, a money-back guarantee, and a one-year free replacement warranty.

The manual is pretty easy to understand and has clear instructions on how to wire the transfer switch.

An additional benefit of this transfer switch is that it fulfills the latest National Electric Code (NEC) requirements.

That means you are getting a quality product that will not create any problems or accidents with your local authorities or inspectors.

The transfer switch also has got an automatic on/off feature, which allows it to turn off during power failures or emergencies automatically.

This is a great safety device that will protect not only you but your appliances as well.

Why its Great
  • Easy Installation
  • This only allows 6 circuits
  • Watt Meters Keep You Safe
Flaws but not the Deal Breakers
  • No wires from the switch box to socket
  • AFCI Breakers Issues

For up to 12000 watts Generators

Reliance Controls 51410C Pro

reliance controls 51410c pro
reliance controls 51410c pro

The Reliance Controls 51410C Pro is a great option for anyone looking for a heavy-duty transfer switch.

This kit is specially designed for the handling of Power watts up to 2,500 watts of power, making it perfect for powering nearly the entire household.

It features a rugged steel cabinet, resettable circuit breakers, and double-throw switches, making it ideal for residential and commercial applications.

Additionally, the 18-inch flexible conduit whip easily attaches to a load center, and the maximum generator running watts is 12,500W.

This heavy-duty transfer switch also features 10 single-pole circuits and 5 double-pole circuits, with a maximum of 10 single-pole circuits and 5 double-pole circuits.

Why its Great
  • Built strong
  • 12,500 Watts Peak Running Generator
  • Installation is quick and simple
Flaws but not the Deal Breakers
  • The only problem was identifying the wiring

Installation of Generator Transfer Switch

The transfer switch is installed on the line going into the main panel (a.k.a. ‘sub-panel’), where your electric meter is located, and it installs between that line and all of your home’s electrical boxes.

If you have an existing sub-panel with breakers, then the transfer switch will plug into that; otherwise, you’ll need to install one before you can get started.


In most cases, you’ll need a platform that’s at least 3ft x 4ft to set the generator on while it is operating and enough space around it to get several people safely around it when in operation (generators produce carbon monoxide fumes which can be deadly if combined with insufficient ventilation).

The transfer switch is mounted on the base, and the generator is plugged into it with special cords designed to minimize noise.

The system requires an interlocking connection which means you can’t operate the generator until the cord is properly connected to both devices.

One of the important steps while installing the transfer switch is to make sure that your home’s main electrical feed (the wire coming from the utility company) is properly disconnected before working around it.

This means switching off all of your home’s breakers at the main panel and pulling out any fuses protecting lines to appliances on that circuit.

Your utility company will typically provide a disconnect switch near the meter, which you’ll need to pull out and use near your sub-panel.

It’s important to double-check that all appliances are unplugged before working on this line.

If you have an older home with knob & tube wiring (wires wrapped in cloth insulation), or if your generator has an open frame design that doesn’t shield the exhaust from your home, you should disconnect this line at the main breaker inside of your house as well.

The next step is to connect a length of heavy-duty 10/3 type SOOW cord from the shutoff switch, which you pulled out near the meter box, to where you’ll have room to operate the generator.

If you are using a sub-panel for this project, ensure your new cord runs from that shutoff to the transfer switch (not directly into the main panel).

The Company provides a ‘super socket’ that connects these lines and allows them to disconnect quickly in an emergency. Make sure it is correctly wired before continuing.

At this point, you’re ready to set your new transfer switch in place (make sure it’s facing the right direction so you can access the plug receptacles) and start hooking up your appliances.


Most modern transfer switches have three duplex outlets for connecting appliances, typically labeled ‘1’, ‘2’, and ‘GEN.’

Before plugging in any appliances, flip the system’s main breaker to the ‘On’ position.

Ensure that your appliance cords have been installed securely to their respective plugs before operating them from the generator.

Now add a few drops of oil to each motor before turning it on for the first time to help prevent overheating.

Once everything is hooked up and ready, go back inside of your home and flip the main breaker (near your meter box) OFF again.

This will be the ‘Master Disconnect’ for this system, which means that every appliance will immediately stop drawing power from your home when you disconnect it.

You only need to do the above steps once since you’ll hook up your generator in exactly the same manner every time after that point.

Now that everything is installed and ready to go, you can plug in your generator using the special cords designed for this purpose.

The red cord should be plugged into the ‘1’ slot on the generator, and the black cord should be plugged into the ‘GEN’ slot.

Make sure that you keep them unplugged from anything else during this process.

It’s possible to accidentally reverse these two plugs if they aren’t disconnected first, which would mean your appliances will still think they are running off of your house’s current instead of the generator.

Once you’re plugged in, switch your generator’s circuit breaker on (preferably with its own transfer switch); now press the start button to get it up and to run.

Once everything is going smoothly, flip either of your home’s main breakers back to the ‘On’ position, followed by each successive appliance.

You may need to go back outside and toggle the generator’s breaker switch a few times before everything runs again, but it should be smooth sailing.

Types of Portable Generator Transfer Switch

There are two types of portable generator transfer switches: manual and automatic.

Manual Transfer Switch

This type of apparatus is only found in smaller engine generators, like those used for RVs and small cabins.

It’s typically mounted on top of the generator (or sometimes inside) and allows you to control every stage of the transfer process manually.

Manual Transfer Switch for the whole house must be operated with extreme caution since it is possible to lose power to the entire system if you aren’t careful.

Unless you drill down into the nitty-gritty details of how these switches work (such as with some on/off toggle), it’s highly recommended that you leave this kind of operation up to a professional who is well-versed in its proper use.


  • Convenience – manual units are very simple to use. Just switch over the power source, and that’s it! No worrying about your house lights automatically switching on or having to control the generator manually. The process will be fully automated.
  • Flexibility – automatic transfer switches let you choose when you want electricity; however, manual switches do not give you that liberty.
  • Cheap – manual transfer switches are a fraction of the price of automatic ones. If you don’t need to swap from one power source to another frequently – this could be a great option.
  • Easy to Install – as mentioned earlier, manual transfer switches need minimal work and effort to install, making them a lot cheaper than their automatic counterparts. It’s recommended a whole house manual transfer switch.


  • Not suitable for frequent generator usage; if you frequently engage your generator throughout the year, a manual switch will not work as you will have to switch things over every time. This is a real inconvenience and might make the whole process of temporary power very stressful.

Automatic Transfer Switch

A more advanced transfer switch allows the generator to toggle between incoming power and its source automatically.

A few models can even completely disconnect themselves from everything while their motor is running, which allows people to continue using power for things like refrigerators while they’re operating on backup power.

The most common failure mode with generators that use automatic transfer switches is for the pneumatic switch inside to get stuck in the middle, leaving everything connected between them and the source without power.

This typically happens when people try cleaning their generator’s filters right after turning it off (by disconnecting one side or another), which can cause problems if they don’t take care of it immediately afterward.

Automatic Transfer Switch-Pros

This type provides a more convenient and easy solution

  • Suitable for standby generators
  • It saves you from knuckle-biting transfer switch wiring

Automatic Transfer Switch Cons

  • Expensive as compared to manual transfer switches.
  • It is not recommended for portable generators. It’s not a whole-house transfer switch for a portable generator.

Conclusion: The choice between an automatic and manual transfer switch is mostly a matter of personal preference.

Try thinking about what you need from your generator and how often you plan on using it, and that should be the deciding factor in choosing between one or the other.

So long as you take all safety precautions into account, either switch type is fine.

Precautions & Safety Tips

No matter which type of transfer switch you have, you should know that the best way to avoid accidentally causing electrical overloads is never to disconnect anything from a generator when it’s still running.

This is why they rely on automatic switches. The only time you’ll need to do this with any regularity is when you’re using their internal motor for some other purpose and not powering something from the outlet.

If you’re worried that you may not have been thorough enough in keeping track of whether or not your inverter‘s internal outlets were still on when you turned the machine off, the best thing to do is gather everything back together and plug it all in at once. If there are any problems, one of three things will occur:

  1. The generator will continue working as it should, and you’ll know that you just need to be more careful next time.
  2. If the entire system continues running, but something happens to stop working, then you’ll know that leaving one of the outlets on was what caused the damage (and it’s likely something that’s easy enough to fix).
  3. If the whole system shuts off, then you’ll know that everything was off, and it’s likely something unrelated to the transfer setup.
  4. If you connect a portable generator to your household power lines without a transfer switch, it could back-feed the electrical lines in your home. This could hurt people and damage property. For this reason, you must always connect generators directly to your house wiring using special equipment called a “transfer switch.”
  5. Never use an indoor extension cord when connecting a generator because the cord could overheat and start a fire.

You should always start your generator outside of any building or structure to help prevent an explosion should there be a gas leak, and allow everything time to run for at least 10 minutes before turning it off.

This will help prevent carbon monoxide poisoning (inhaling this stuff can cause nausea and fatigue and make you feel like you have a hangover even if everything else is fine), as well as wear and tear on your generator.


What are the benefits of a generator transfer switch?

The benefits of a generator transfer switch are that it allows the power from your house’s utility company to be transferred onto the backup generators.

This way, you can access electricity when there are outages in service, so you don’t have to lose what you need most.

Why would I need a generator transfer switch?

A generator transfer switch is needed when you need to move the electric power coming from your home’s grid and run it through a backup generator.

These devices can be necessary during emergencies where there are outages in service and your community cannot provide electricity for homes and buildings.

Where would I place a generator transfer switch?

A generator transfer switch can be placed anywhere in the building where it is readily accessible.

It should not be far away from your backup generator, preferably right next to it or very close by—the more accessible the transfer switch, the better.

How to wire a whole house transfer switch?

A whole house transfer switch is pretty similar to a manual transfer switch, and it should be wired in the same manner.

Before installing your generator, you will need to gather all the information about setting up this device properly.

How to install a whole house generator transfer switch?

A whole house generator transfer switch is not that difficult to install because you just have to follow all the instructions provided in the manual.

It should be pretty straightforward for anyone to do without much hassle.

We have added some videos in our article to help explain how it works and how to install it.

How much electricity can they handle per hour before failing to work properly?

A generator transfer switch can handle up to 10,000 watts per hour.

This is usually enough for most homes. If your home requires more than the usual running power, you will need a bigger generator with more wattage capacity.

Final Verdict

Portable generator transfer switch kits are important for generators as they allow the power from your house’s utility company that runs through your home to be transferred onto the diesel or gas-powered backup generators.

This way, you can still have access to electricity when there are outages in service.

It is important to note that these devices do not need any kind of external source to work because they rely on existing electrical currents already running within the walls of homes and buildings.

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