How to Connect Generator to House without Transfer Switch?

How to Connect Generator to House without TransferWhen power blackouts happen, most homeowners grab a generator, start it and hook it to the house. While that might work, it’s never safe to use the generator power without the recommended installation procedures and connect your generator directly to your house. The most repeated compromise generator users tend to do is connecting the generator power to their house without a safety switch. Even though generator hooks up isn’t a complicated process, there are certain things that you have to follow. Today, in this post, I will take you through the several safest steps on how to connect to house without transfer switch.

You have to remember that for your power-backup generator to run efficiently and safely, you need to do the hook upright. What do I mean? Since we’re talking about connecting the generator without a transfer switch, you still need a better alternative. Transfer switches tend to be costly, including their installation. I think that’s why most people prefer connecting their generators without them. If you’re considering following the same steps, well, I better show you how to do it properly.

What Do You Need?

Before you can engage yourself all the drilling and the wiring, there certain things you need to gather that will help protect yourself and smoothen the process. Remember, you’re dealing with electricity, which means you must be prepared with the right tools. Once you have everything within your reach, half of the job is done. I recommend you keep all the gears with you always if you want to safely connect your generator to your house without a transfer switch.

These are the items you need:

An Interlock Kit

Before anything else, you need a transfer switch alternative, an interlock kit. The device will help you connect the generator safely without a transfer switch. Before you go picking any interlock device you come across, remember that you need a model that matches your generator. It must be made for your generator version to match its power. The best part is, the interlock devices are price-friendly, and you can buy them in any electronic store.


Here the main concern is the type of generator you have. Check if you have a 20A or a 30A generator. You also must get the best breaker that suits your home specifications. Most 2-pole double breaker rated 30-am power meets most home power-back generators.


You cannot use any electrical wires for all generators. You have to consider the area of the property you have. Using the wrong gauge wire can lead to overheating and melting, or the power might be lost in the wire resistance.

If you need a 20-amp or 30-amp generator connection wire, get 10-gauge wires. The colors of the wires should be different for more straightforward accessibility while you work it out. Work out the area of the space needing wiring and get the right length wire.

Under this, you still need to get the ideal outdoor Power Inlet Box that will allow easy generator hookup and keep the hookup safe and weatherproof.

Safety Measurements

It would be best if you also cared about your safety before you even start this work. Dealing with electricity isn’t something to take lightly when it comes to safety. It would help if you got electrical-rated work gloves to protect your hands. Get some protective eyewear to protect your precious unreplaceable eyes. It would help if you also had a pair of electrical work boots to protect you from getting electrocuted.


Lastly, on things you need is the tools you will be using to connect all the pieces. Get a pair of pliers, screwdrivers, wrenches, electrical tapes, chisel, a huge-bit drill, and standard electrical gears.

Figure out Plug Type & Amperage

Now it’s time to investigate the type of plugs you need for the generator. Remember, you will need to connect the generator using a connecting cable with the right male and female plug. Check on the generator if you’re using a 20A, 30A or 50A plug. You might also read some codes written on it and use them to adjust the materials you’ll use.

Drilling the Plug Hole

Now that you know the type of plug and the wires, it’s time to drill a hole on the wall to pass the cables and set the outdoor plug. Before you can drill, pick a spot away from the windows and doors, where you will keep the generator and not get CO poisoning.

The hole you drill will aid in passing the electrical wires to your house, and that’s why you need to make the hole large enough to allow the wires to pass freely. If your house has thick walls, you can use a hammer drill, instead of a standard bit drill.

Please do the right drilling in all the intersection that the wires will pass through till they reached the junction box. You can decide to use the shortest route, but make sure it’s not a shortcut; it needs to be as clear as possible.

Assembling and connecting the materials

Method 1

If you own a portable generator, you don’t need the interlock device. You can use your high-power extension to connect the essential appliances in the house. What’s more, the generator can use either a 20-amp plug, a standard AC plug for light appliances, or the 30-amp plug.

Drill a hole on the wall to the outside, run through the standard generator wires, and install wall plates on both sides. On the outside, use a watertight, weatherproof outdoor plug. On the interior, you can use regular three-pin plugs, and on the outside, you have to match your generators plug.

This process is simple as once you’re done, you can connect the generator, plug in your appliances to the newly installed plug and you’re good to go. The issue with this method is, it’s tedious as you have to shift the appliances manually. It’s also not safe as there is no breaker used.

Method 2

It’s time to get your hand dirty. At this point, you need to get real. You first need to shut off the main AC breaker before you can touch anything on the power box.

Mount the power inlet box and ensure the hole is watertight. Do the conduit work and assemble it. You can use some glue to ensure the attachment is done right to keep everything safe.

Run the wires through the hole(s) you drilled till they reach the junction box. Pull the wires one at a time and fix them to the plug. Remove a 3/7-inch of the insulation and use a screwdriver to tighten the wires to the plug.

Match the colors with the labeled color on the plug. Green for the ground wire. White or brown for the neutral and red or black for the live plug.

Now comes the tough part, fixing the breakers and the interlock device. Remember, you have to make sure the AC power is off before you touch anything inside the breaker box.

If it’s, now install the breaker near the AC breaker and opposite it. Why? You have to install the interlock device between the two when the AC power is on the generator, or the backup power is off. It would be best if you placed the breaker right; I mean, install it where you can prioritize the items to connect to that backup line.

You can also have a dedicated generator power panel that allows you to direct the power to most essential appliances needing power during a blackout. Once you install the standard junction box, you will have to run a different set of wires to the items that need it. It might be costlier but exceptionally safer.

Once you’ve installed the breaker, you can now install the interlock device. Please read the installation instruction and make sure it fits well between the two breakers. Adjust the position to ensure when the AC power is on the generator power is off and vice versa.

When done installing the interlock device, you can now pull all the wires and connect them to the breaker retainer and finish it by covering it again.

Is it safe to connect my generator to the house without a transfer switch?

Even though it’s a requirement by the national electric code and the easiest and safest way to power your house during an emergency, it’s not a must. You can still use the interlock device, the best alternative to a transfer switch. The interlock device is even cheaper to buy and install, and some consider it safer and more comfortable when using a portable generator.

Final Verdict!

I have to warn you first; I’m not a certified electrician. However, this is an advice I have given most people and worked out quite well. If you follow it to the point, well, you won’t suffer again during a power emergency. Do I need a permit to install my generator? You may ask. Even though it’s technically a requirement by local authorities when installing anything new and permanent to your home, you can get help from a certified electrician for the permits.

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About the author

Sharif Miah

I am Sharif, 22, a student, currently doing the BBA program. Besides, I am an online Blogger.

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