How To Connect Generator To House Without Transfer Switch?

The best way to connect a portable generator to your house is to use a transfer switch, but if you don’t have one, the directions below detail how you can still have power during emergency situations.

Keep in mind that you should only attempt this if you’re comfortable with the procedure and you’re willing to take full responsibility for any damages that may result.

In the event of a power outage, a generator can keep your home’s essential appliances and electrical system up and running.

But to do so, you need to connect the generator to your home in the safest way possible. Fortunately, this is not as difficult as it may sound.

The good news is that in most cases, you can connect a generator to your home without having to install a transfer switch.

Is a Transfer Switch for a Generator Required?

A transfer switch is used to change the power sources in your home.

Basically, it’s the mechanism that helps keep the power running smoothly after a power loss.

Although a transfer switch is not technically required for your generator, it is highly recommended by specialists.

Any generator with a power output of 5000 watts or more is required to incorporate a transfer switch for safety reasons.

Power at this level necessitates the installation of a regulator to prevent surges and grid back feeding. A portable generator, however, does not require one.

With a transfer switch, you can rest certain that your power will not cause any issues or put anyone in danger.

The power from your generator should never be sent via your central unit’s primary channel when switching back from your generator to a central device.

This phase is crucial because if the generator fails, the power it produces might be exceedingly harmful.

An automatic transfer switch instantly switches power from the main power to the backup power or backup generator.

Automatic transfer switches are always ready to relay the power over to the generator. Whilst with manual transfer switches you have to flip the lever on your own.

Learn about the restrictions in your state and avoid doing anything that can be illegal due to safety concerns.

However, there will come a moment when you will have no choice but to do without one.

Let’s have a look at the best methods to use your generator without requiring a transfer switch.

How to Use a Generator Without a Transfer Switch?

Connecting a generator to your house without using a transfer switch isn’t an easy task.

The first thing you need to do is to make sure that your generator is grounded properly.

If it isn’t, then there’s a risk of electrocution if the power lines come into contact with the metal frame of the generator.

Please keep in mind that you will need to employ a transfer switch for your generator to work securely.

Using a generator without a transfer switch is never the best option. It will, however, be OK if you find yourself in a situation as I did.

When working with electricity, you need the correct tools. Half the task is already done when you have everything in front of you.

Of course, you’ll need the necessary guidelines, but having everything ready to go is a terrific approach to get started.

Here are a few tips: First, make sure that the generator is properly grounded. Then, connect one end of a heavy-duty extension cord to the generator’s output terminal.

The other end of the cord should be connected to an appropriately sized outlet on the outside of your house.

Step 1 – Having the Right Tools Available to You

  • The Interlock Kit: The interlocking kit allows you to connect your generator without using a transfer switch.

Make sure you get one that matches your generator’s model. They are one-of-a-kind for each version, although they are affordable and widely available.

  • Breaker: Select the main breaker that is compatible with the generator you possess.

You should also select one that meets your home’s requirements. A two-pole double breaker with 30 Amp power will work for most generator specs.

  • Electrical Wires: It’s a good idea to acquire at least three sets of wires because they differ based on the property.

10 feet of 10 gauge wires should be used. Working with electrical cables is difficult for a rookie.

But if you’re prepared to put in the effort and be patient, you’ll be OK on your own. Get wires of different colors so you can readily recognize them while working.

  • Safety Measures: Your primary focus should always be safety. Working with electrical wires is always dangerous, so pay attention to the instructions.

Source a great pair of work gloves and some protective eyewear to safeguard your eyes from any damage. Also, work boots will help guard you against electrocution.

  • Other: The rest of your tools will be ordinary DIY goods.

Pliers, wrenches, screwdrivers, electrical tape, a hammer drill or chisels, and General Electric gears are among the tools needed.

These tools are often found in a standard toolbox.

Step 2 – Figure Out Plug Type and Amperage (National Electric Code)

The first step is to make sure you know your generator’s plug type and its amperage.

A NEMA (National Electrical Manufacturers Association) code will be there on each new plug you buy.

These are standardized codes for plugs and receptacles that assist customers in telling the difference between varying voltage and amperage combinations.

The NEMA code helps to prevent short circuits, electrocution, and even electrical fires caused by incorrect amperage and voltage combinations.

Plug ratings typically vary from 125 to 600 volts and 15 to 60 amps.

Furthermore, they are classified as single-phase or three-phase, but we are only concerned with single-phase with common generators, which restricts how much we need to know about receptacles and plugs.

The designations are quite straightforward. Some examples are NEMA 5-30P or NEMA TT-15. For more details please check out this article by TrekPower.

Step 3 – Create a Place for the Outlet Box

For the next step, you’ll need a location for the generator’s utility box.

This is a terminal box for electric wiring or fittings where the wires terminate for connection to electric fixtures or appliances.

To create a place for the outlet box, drill a square or rectangular hole that will suit your outlet. An oscillating tool is required for wood and drywall.

For a concrete or cement wall use your drill instead.

Create a hole outside of the wall, using your drill to route your wiring/cabling from the outside of your home.

To avoid harming the wires during the installation into the outlet kit, make sure it’s larger than the estimated diameter of the wires.

Step 4 – The Waterproof Box

On the exterior wall, mount your waterproof box. It assists in preventing harm to your end plug.

The end plug can be covered with any sort of safety box. You may, however, require a larger safety box to accommodate all of your wirings.

Step 5 – The Wiring

Insert the other end of the wires with a wall socket outside your house to connect the wires to your outlet kit.

You may now assemble the outlet kit inside after inserting the line.

Seal the exterior and interior holes with sealant after assembling the outlet and wire. This is required to waterproof your installation.

Step 6 – Connect To Outlet and Test

Now it’s time to put everything to the test. To test this, switch on your generator and plug in the inlet socket (in the power inlet box).

The extension cords are then connected to the generator inlet plug. To acquire some readings, connect your power consumption tester.

Connect some of your home appliances and electronic devices with a power rating that your generator can handle.

Take note of how many watts of power your generator produces for each of them.


Remember that the exhaust gasses must flow through an open channel.

If you’re not sure if your work is legal and up to code, we recommend having it examined by a licensed electrician.

Different states have different laws, so make sure you learn everything you need to know first.

This is the only way you can avoid any code violations. Also, remember to stay safe, and we hope we were able to assist you in the proper course.

If you have any questions, please post them in the comments section below. We’d be delighted to assist!

by Richard Kelly

Having experienced significant success as a house flipper, I am often approached with questions about all things home improvement. That’s why I decided to start this site. My objective is to share all of the insights I have accumulated over the years so other people can design the homes of their dreams.