How to Connect Portable Generator to Electrical Panel?

How to Connect Portable Generator to Electrical PanelWhen a hurricane, storm, and other natural disasters hit, this is the time most of us realize the benefits of having a power generator. Some of us have a portable generator but don’t know that it can help.

With a powerful portable generator, you can run a couple of appliances in your home and keep your family safe. However, you do need to connect it properly to serve you well, especially for the hardwired devices. Here are tips on how to connect portable generator to electrical panel.

Ways to Connect Portable Generator to Electrical PanelThe ways to Connect Portable Generator to Electrical Panel

Step 1: Gather the tools and parts

You need a long cable 12/2, 20-Amp cable or 10/4, 30-Amp cable, wire nuts, a wire cutter, non-metallic Sheathed cable clamp connect, and a drill. The cabling needs to be the recommended one. Check with the planning department or the power department on the legal cable required for home use.

Step 2: Relocate the existing breakers

Turn off the electrical panel breaker in your home circuit to ensure that the electricity is isolated from your home general power grid. Ensure everything goes off, and all the breakers slots are on off position. After that, you now need to install a new generator breaker depending on the rating on your generator. Mostly, I would recommend two 30-amp circuit breakers, but you should consult with an electrician.

Step 3: Install the Service Cable and the Feedback Circuit Breaker

Here you need to route the service cable from your main home panel to the main power inlet box. That requires you to knock off a small hole from the main panel top and install a 2-inch NM cable clamp connector. Next, you need to direct the service panel cable through and ensure it doesn’t touch any energized parts.

Give it an extra length to allow you to move it inside the service panel with no kinks, but gentle curves. While on it, attach the white-neutral wire to the neutral bus bar and the red and the black hot wires to your newly installed circuit breaker. Lastly, attach the service feedback breaker to your home main service panel.

Step 4: Install the Inlet Box

Now that you’ve done the necessary wiring in the electrical panel, it’s time to take the wires to the inlet point. Drill a hole in your wall in a downward angle to prevent water from dripping back to your house.

Disassemble your inlet box and tightly attach its back bracket on the wall and insert NOALOX into the wire receptacles. Once you’re done, it’s time to screw the wires and ensure that white goes to the neutral point and green to the ground terminal. The hot red and black should be connected to the live, silver terminals.

While at it, get the appropriate wire cable for joining the generator to the inlet box. It should have the generator rated requirements. On top of that, the flanged connector connecting end needs to have a female twist lock while the generator ends a male twist lock.

Step 5: Install the Interlock Kit

There two ways to legally prevent your generator from back-feeding your electricity line, either by use of a transfer switch or an interlock kit. A transfer switch is much expensive to buy and install compared to an interlock kit. But, since you’re dealing with a portable generator which most of the times won’t be connected to this line, there is no need of going expensive.

So, here is how you connect an interlock kit:

First, you need to remove the screw holding the main service panel circuit breaker shroud. Then attach the feedback circuit breaker’s metal plate. Once you’ve done that, flip the electrical panel cover and also line up the top screw hole template.

The next step is to align the cover plate and also drill a small hole using a 3/16-inch metal drill bit. Flip your panel cover and re-drill the holes using a 5/8-inch drill bit. Yes, this the last and the hard part. You also have to remove the metal shard from the panel backside using pliers.

After that, line up the interlock’s slider on the electric panel cover and install it using three screws. Add the interlock’s notification sticker on your electrical panel cover door and test it to ensure it slides properly without resistance. It should block one circuit breaker from coming on unless the other is off. That’s is its sole purpose.

Step 6: Have the connection tested

If you’re not a certified electrician, have the line inspected. That will help you avoid future problems with the power company, planning agencies, and the insurance company. It will also help you ensure that everything is ok before you can start using the generator. Ensure you place your generator far from the house to avoid Carbon poisoning.

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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.


  • I have an older circuit breaker panel (Square D) brand and there is some extra room on the panel to install a 30 amp breaker. Does it matter where I install the new 30 amp breaker switch or is anywhere it will fit o.k. It is basically like the 60 amp breaker I installed for my hot tub.

    • Well, the question here is, what do you want to run off the 30-amp breaker? Does it support the load? If so, then all you need is a room for the neutral and the ground bus. If you got that, then you can connect it wherever you want – anywhere with a room for the hookup.

  • I am going to plug in a portable generator breaker and run a 30 amp rated extension cord between the panel and the generator outside of the house. I will also have a main breaker lock out so the generator can’t back feed to the power company.

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