How to Wire a Generator to a Breaker Box

How to Wire a Generator to a Breaker Box

A generator can be considered an extra power source or backup. It provides a power source when there is a power outage. Or when power is needed during an outdoor activity. Getting the generator connected to your home is very essential. You should keep the generator wiring stable, and not until when you need it that you start wiring it. And the best choice to go for is making use of the breaker box. This is because when emergency power is needed, all you need to do is put on your generator. And if need be put it on on the breaker box. This article has highlighted the step-by-step instructions on how to wire a generator to a breaker box.


Getting a generator is the best choice. This will make up for the emergence need for electricity whenever there is a power outage. And you should know that the next power outage is not predictable. Some emergencies like an infrastructural problem, rain, storms, 0r natural disaster may cause power outages at any time. So, it is reasonable to get an emergency generator for backup.

Your portable emergency generator should get fixed to your house using a transfer switch. The transfer switch will change over from the mainline source of electricity to the generator source and vice versa. It is safer than just getting the generator connected to your house using an extension. It is only advisable to use an extension with a portable generator when you are outdoor.

Making use of a transfer switch breaker is required by law to get your generator connected to your house. It prevents back feed. Back feed may cause damage to your home, and even get an electrician working electrocuted. It is a trouble-free way to get your home powered. And with it, you can get any of your home appliances units connected to it.

Another important advantage of a transfer switch is easy to power management. You can easily put on or off any appliance you don’t need at a particular time. Getting your generator connected to your house might seem complicated. But with the right step, there are to get it with ease. And without knowing it you are eventually working on the breaker box. 

Hook Up Generator to Breaker Box

Now let’s go into the steps needed to get your generator connected to the breaker box.

Materials You Will Need

To get your generator connected to the breaker box, you will need a few materials. These are:

Double pole breaker with 40-amp power

Stripper Tool.

Eight-by-three cable.

Screwdriver (with flathead).


Transfer Switch

Inlet box (recessed male connector) Generator Cord

Get to know the wiring idea

The first thing is to understand the concept of how to wire a generator to a breaker box. If you have a 240 Volts circuit, you will need two wires that together make a 240 Volts. That is each of them is of 120 Volts. And then a ground wire which is usually green or copper-brown. You can make use of a 240 Volts circuit in place of both 120 Volts and 240 Volts. This is because the neutral wire might be absent in a 240 Volts circuit. You can make your wiring directly if your generator is 240 Volts.

Put off all the Connections

Turn off the main power source in your house. You can make use of a voltmeter to check if any part is still on. This is to guarantee safety. Another thing to check is the electricity termination. See if it is done in the right way. Wait until the electricity stops flowing before you start any work on the breaker box.


This is where you will make use of the 8 by 3 cable wire. Peel open about half an inch of the cable. Ensure that you expose the end of each of the wires to about half an inch. To get a neat cut, you can make use of the stripper tool.

Screwing Wires

The circuit breaker should contain two screws which are meant to help hold the wires in place and appropriately. Gently screw the black wires to the circuit breaker, insert the wires fully into the terminals. Next, you tightly screw in the screws, make sure that they are secure and would not come out.

Breaker to Service Panel

Now, you have to install the breaker inside the panel. Find a suitable place in the panel where you want your generator circuit to be. Make use of the forth and back action to fix the breaker inside the panel at that spot you choose. You have succeeded in fixing the tabbed end of the breaker in your home. Next is to snap the rest of the breaker to finish the installation.

Check the Double Pole Breaker

You need to inspect the double pole breaker to make sure that it is tightly fixed. This double pole breaker is equipped with a couple of 120 Volts hot wire. And together they add up to 240 Volts. And it is the best use for a 240 Volt installation.

Installing the wires

Let the ground wire pass through till it reaches the end of the 240 Volts receptacle. The receptacle is in the breaker box. Then crew it tightly there. Next, insert the 8 by 3 cable wire to the outlet you want to plug your generator in. Install the two black wires each into the two colorless screws and tighten them firmly. Fix the green wire into the green screw and tighten it very well for it to stay in place.

Set up a Breaker Retainer

You have to prevent your generator breaker from moving. So you have to pick it down by installing the retaining bracket.

Fix Interlock on the panel cover

Turn over the panel back and install the sliding interlock bolts on it. Now reinstall all the breakers on the panel. Make sure the breakers are in off position. Turn on the generator breaker while the main is still off. And make sure that the interlock allows for the position of the generator breaker. Or you need to change the panel cover’s position. Next, turn off the generator breaker and put on the main. Drop the slid so that the generator breaker will not turn on. Make sure that the main can be turned on easily. And if not you adjust the position of the panel cover.

Attaching the outlets to the wall

Now that you have secured the 8 by 3 cable wire in place. The next thing is to fix the outlets to the wall. Once you are done fixing the outlet, put on the main power switch and also the breaker box. Plug your generator into the outlet which you have fixed. Start your generator, and your power is on.

Important Tips

Make sure you comply with the wiring color code. And that the 2 lined wires for the voltage are of the same color. If necessary, you can make use of tape to distinguish them.

Also, ensure that you check with a good voltmeter to make sure that the power has been terminated properly.

An 8 by 3 cable is the most accepted when you are working with a 40 Amps breaker box.


A portable generator is important to keep your house lighten up. And to get some essential appliances working in case of a power outage. The most suitable way to get your generator connected to your home is by making use of the transfer switch. After that you are done with your setup, you might get it inspected by a professional. This is to correct any error that you might have to make while making your connections. They will inspect the output, the voltage, and the safety measures you should have put in place. And they will correct anything out of order. This is the recommended way on how to wire a generator to a breaker box.

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