Power Inlet Boxes for Portable Generators

Power Inlet Box for Portable Generator

Power Inlet Box

Having a generator as a backup power source for your house during power outages lets you have electrical power to run your home.

Many people use portable generators as a backup source of power for their home while some use standby generators. Though both these types of generators can easily supply your home with the electrical power you need, you must be aware that connecting the generator to the electrical circuit in your home will require you to install a transfer kit whereby the power from your generator is transferred safely.

Using this system also eliminates running electrical cords from your generator into your house and you can connect the transfer switch to those circuits in your home that you would need to use during a power outage.

Basic Need Xfer Switch Kit

A transfer kit consists of a transfer switch and an inlet box to which you connect the power from your generator. These inlet boxes are available in different sizes depending on the amount of power that your generator can deliver as well as the amount of power you want to connect to your home.

Inlet Box Amp Sizes Vary

You can find inlet boxes rated for 20 amps, 30 amps as well as 50 amps. Usually these inlet boxes are mounted on the outside of your home while the transfer switch is mounted inside your home.

Generally you can find these inlet boxes made either of plastic or aluminum and they can have either have straight plug ins or twist lock plug ins.

Inlet Box Considerations

When you think about installing an inlet box to transfer power from your generator into your home, you need to consider a few things.

The first is the maximum amps your generator can deliver since you would want your inlet box to be of the same amps.

Next you would need to consider where you are going to install the inlet box and the weather conditions of the place you live in. Since these inlet boxes are mounted on the outside of your home they need to be able to keep the inlet safe from rain, moisture and dust. Most of the inlet boxes that are available come with lids that keep the inlet safe.

Having an inlet box installed on the outside of your home means that it would have to endure all types of weather conditions. In this situation you need to install an inlet box with a NEMA rating of 3 or 3R since these type of inlet boxes are rated to withstand all types of weather conditions including rain and snow.

You will also have to consider as to the gauge of the wire that the inlet box can handle and as to the type of plug in that you would want to have. Most installation instructions can help you with either pre-wired or proper call outs of wire to obtain.


These inlet boxes vary in price from about $20 to $75 depending on the type and the amperage rating. The inlet boxes with straight pins are usually cheaper than the twist lock type. Also the plastic inlet boxes are cheaper than the aluminum types. Again the box selection should be made on NEMA rating for outdoor use.

Here are several options and prices you can check to see if they meet your needs:

L14-30 30 Amp Inlet Box 50 Amp Inlet Box 30 Amp Raintight Inlet Box 20 Amp Straight Blade Inlet
Brand Reliance Products Reliance Products Generac Marinco
Part Number PB30 PB50 6337 0310.2598
List Price $49.99 $67.99 $42.99 $25.95


If you are not knowledgeable when it comes to installing an inlet box and a transfer switch in your home to get power from your generator, it is best if you have a qualified electrician help you choose the best type of inlet box as well as install it for you.

When you connect your generator to the inlet box installed in your home you also need to see that you have the right size power cord and plug. The cables can come with different types of plugs and you can find one that suits your inlet box and generator.

Having a power cord or cable that is sized correctly for amps and voltage is important since you do not want to have the cable heating up or not transferring the full power to your home.


Having an inlet box and a transfer switch to transfer power from your generator to your home lets you transfer the power safely. These systems are designed so that the power from your generator does not flow back into the utility lines thereby causing a hazard to the utility workers working on the power lines during a power outage.

Also having a system of an inlet box and a transfer switch allows you to connect only those circuits that you would need running if your generator cannot supply enough power to run your whole house.

Though inlet boxes are usually installed on the outside of the home, there are transfer switches available with built in inlet boxes or plugs. Depending on your code requirements and the type of generator you have, you can find an inlet box which suits your purpose.

It is best though to have these inlet boxes and transfer switches installed by a qualified electrician who would be aware of the codes required and be able to install them so that you can safely and easily transfer power to your home from your generator whenever you may require to do so.

Brands of Inlet Boxes

The most common brands available in these inlet boxes are Reliance, Generac, Leviton, Emergen, Connecticut Electrical, Eureka, and Garden-Outdoors.

Here’s a few for your consideration:

Comments are closed.


Pin It on Pinterest