How to Hook up a Portable Generator to a House (in 12 Steps)

A portable generator is a must to all households.

Sometimes we have to pause what we’ve planned to do just because the main power source goes out, and that’s inconvenient. Fortunately, having a generator will give your home emergency electrical power for your needs.

It doesn’t mean the generator supplies power to all appliances; in fact, only essential services, such as lighting, fridge, TV, etc, are provided. In case of air-cons, washing machines, and stoves, they require too much power than a typical generator can supply.

How to hook up a portable generator to a house?

We’re going to discuss this matter today!

Table of Contents

12 Steps to Connect a Portable Generator to a House

Many don’t put much thought about how to power their necessary items during a power outage. The grid is down normally within a few hours; however, it can last to several days in some countries. Especially if the main power goes out during the winter and you can’t use the electric heater, it will be a disaster.

Having an emergency generator is great but not enough.

According to experts, you need a generator transfer switch so that the machine can power your home legally and properly. There are 3 main types, and each comes with specific benefits, complexity, and expense to choose from:

Breaker interlock
Manual transfer sub panel switches
Automatic transfer switches

Continue reading to know 12 steps to hook up your generator to your home:

1. Determine the plug type and amperage

The very first thing to do is to find out your generator’s plug type and amperage type so that the process can be carried on. The data is written near the plug; for example, mine is L14-30 – 30 Amp.

Based on what I’ve researched, three common sizes are:

Nema L14-20 – 20 Amp
Nema L14-30 – 30 Amp
Nema CS6365 – 50 Amp

2. Gather your supplies

Make sure there is a 30 Amp plug on your generator to continue. If you spot any difference, you have to adjust the supplies. In the following, I’ve listed items for the preparation of this build:

Breaker interlock kit (*)
Wire (10 feet of 10 gauge wire) in different colors
30 Amp 2 pole (double) breaker (*)
30 Amp power inlet box
30 Amp generator extension cord (*)
40 electrical conduit and fittings
Flexible non-metallic conduit and fittings
Conduit body and glue

Note: for the (*) items, you need to buy the types that fit your specific breaker box and plug type’s extension cord. They are not the same – if our generators are not the same, this list is for reference.

You may want to check quick DIY wheel kit for your generator.

3. Look for access hole

Measure and use a hammer drill to make a conduit hole.

The tip here is to drill that hole close to the panel for easy setup later.

4. Mount power inlet box

Remove the front cover from your power inlet box; then, continue removing the knockout and attaching the PVC fitting. For this step, I choose the watertight connector. It’s also okay if you want to use glue.

To fix the power inlet box to the wall, use tapcons.

5. Bring fit and glue conduit to test

Make use of your hand hacksaw and cut the conduit to a proper length. Once you’re sure that it fits for the build, glue it down and leave it dry naturally.

6. Wire the inlet plug

Let’s move to your generator’s inlet plug!

Start with removing the cover on the conduit body; next, thread all the wires through the installed conduit at the same time and attach them to the plug. Remove about 3/4 of an inch of the insulation. Then, tighten the terminals using a nut driver or a big flat screwdriver.

White – W terminal
Black and Red – X or Y terminal for loading
Green – Ground to the power inlet box

7. Push the wires inside

With this step, you need to push the wires inside the conduit into the one leading to your house. Find a conduit body cover perfectly fitting the gasket. If you find any gap between the conduit and your house, fill it with expanding foam or silicone.

8. Prepare the wiring breaker box

Turn off the main power breaker as well as other branch breakers. Use the screwdriver to remove the front panel of the breaker box. Next, take out one knockout and screw in the conduit adapter. Now, pull all the wires pushed through the conduit earlier into the box.

9. Make open breaker space

If using breaker interlock, you need to move a breaker or two down. For those whose box doesn’t have enough room and breaker is 30 Amp (or less), you can make use of a wire nut or a piece of insulated wire.

10. Install wires and generator breaker

Once having enough free space in your breaker box, it’s time to install a new breaker:

White – to the common bond rail
Red – to one terminal
Black – to another terminal
Green – to the ground rail

11. Install breaker retainer

To avoid the breaker from moving, you can consider installing a retaining bracket.

12. Install inter lock for the panel cover

Flip the panel over and go with the given template. Based on the instructions, you should pre-drill the holes; next, turn the panel back over and attach the sliding interlock bolts. See all breakers switching OFF? Turn on the generator breaker but make sure the interlock allows its ON position.

You can shift the panel cover position. When turning off the generator breaker, remember to drop the slide to avoid it from being turned on. Check to see if the breaker for the main power is ON; if not, simply adjust the panel cover.

Attach decals to your breaker box and outside service box.

Check this video to find out a way to install a transfer switch for your generator:

Final Words

So, that’s all for how to hook up a portable generator to a house.

Once finished, you can load test. Place the generator 15 feet away from your house and turn it on to see if the operating speed is normal or not. Check with the breakers and when you’re sure that the generator takes the load itself, you succeed.

Enjoy your setup!

Leave your comment below if having any question!