How To Connect A Portable Generator To Your Cabin

Last updated on December 28th, 2021 at 06:07 pm

Losing power can be more than an inconvenience. During extreme weather conditions, it can be deadly. Here’s how to connect a portable generator to your cabin so you’ll be prepared to survive the worst.

Common Reasons Power Outages Occur

Most of us use grid-tied energy for our personal comfort and lifestyle. Utility companies do their best to provide continuous, uninterrupted power. However, as we all know, outages occur. The primary reasons for power outages are:

  • Equipment Failure
  • Power Grid Maintenance
  • Vehicular Accidents
  • Weather Damage

Equipment failure is rare but does occur. Routine maintenance minimizes equipment failure, but it often requires a scheduled shut-down of power. Vehicular accidents that do damage to power poles and lines are also rare, but they do happen.

In the three situations noted above, power restoration usually happens quickly. This is because the power company is dealing with only one issue. Weather damage, however, can cause widespread problems over a vast area. Utility repair after storms may take only a few hours, but, in extreme cases, outages can last for days or even weeks.

Homesteaders living in remote rural areas in particular need to be prepared for the worst-case scenario.

Alternate Power Sources

Electricity is not the only type of power available to homesteaders. Many choose to live off-grid, making use of alternative energy sources for heating, cooking, and running appliances. These may include:

  • Solar
  • Wind
  • Hydro (Water)
  • Wood-Burning Stoves
  • Kerosene Heaters
  • Fuel-Powered Generators

For those on the grid, these alternate sources of energy can be used for backup power and heating needs. Not all of these options may be practical, affordable, or readily available to every homesteader, though.

For most people who use electric power, a fuel-powered generator will be the most practical backup for emergency situations.

Why We Chose A Generator

We live in a remote area, but our cabin is connected to the electric grid. We use an Aux Mini Split for heating and cooling our 480 SF cabin.

Eventually, we plan to build an additional room onto our cabin where we’ll have a wood-burning stove. To get us through until then, I installed a propane wall heater for backup heat, and we purchased an outdoor propane grill with a side burner for general use as well as emergency cooking.

However, in early 2021, an ice storm knocked out power and left us stranded in our immediate neighborhood while the temperature plummeted to 8° Fahrenheit. We were fortunate power was restored within five hours, but that was long enough for us to discover that our propane heater was no match for such extreme conditions!

With a generator, we’ll not only have warmth in winter but also air conditioning in summer and peace of mind year-round. We’ll be able to charge our phones for communicating and keep lights powered on for safety. With adequate fuel on hand, we can run our generator for many days if necessary. We will be safe and comfortable until power is restored.

Safety First!

The following instruction focuses on how to connect a portable generator to your cabin without utilizing high-voltage applications or needing an electrician. You will learn, specifically, how to install a connection for 120v appliance usage.

If you have no formal training or experience in electrical applications, please consult a licensed electrician. Improper electrical installation and usage can result in property damage, fire, severe injury, and even death.

A licensed electrician can help you calculate the energy you’ll need to select the proper generator and install the necessary connections.

Selecting The Right-Sized Generator

Finding the right-sized generator to match your needs is important.

In our case, after carefully researching and calculating our needs, we chose the Harbor Freight brand Predator 9000 Watt Gas Powered Portable Generator. At 9000 watts, this unit will provide us with power for heat and lighting during the winter. It will power our portable a/c unit or refrigerator running in the summer.

This generator offers both 120 and 240 volt receptacles as well as manual or electric start. It has an 8-gallon fuel tank that will run 13 hours at 50% capacity.

We purchased both the optional battery for easy electric start and the wheel kit for portability. This generator is quite heavy, and the wheel kit with handle is handy for moving it around when needed.

Calculating Your Energy Needs

Before purchasing a generator, you should calculate the energy needs of the appliances you’ll want to power during an emergency. A 9000-watt generator, for example, will provide around 75 amps of electrical power.

Every electric appliance comes with a label indicating the total volts and amps required to operate it. Click here for an explanation of the difference between volts, amps, and watts. The chart below shows typical wattage requirements for common everyday appliances.

Below is the blank Estimate Table that came with our Predator 9,000 Watt Generator. We used this to determine exactly what appliances we can run off our generator.

As illustrated in the chart above, the total Startup Watts for our 9,000 Watt Generator (total watts needed when starting the generator) should be less than 9,000. The Total Running Watts (the Watts used while the appliances continue to operate) should be less than 7,250.

Different generators will, of course, have different totals based on the load they are designed to handle.

Be sure to double-check the calculations each time you use your generator. You will use different appliances with different draws during various seasons.

Special Note:

Although it’s listed on the Wattage Estimate Chart, operating a computer and monitor with a generator is not recommended unless your generator is equipped with an Inverter and Surge Protection. Care should also be taken with cell phones. They can be charged with the generator as long as there’s a 12-volt receptacle.

How To Connect A Portable Generator To Your Cabin

The following instructions will guide you through installing a receptacle to your cabin or building that will allow you to run 120-volt appliances with your generator. These are the most common appliances we use every day such as a light bulb, radio, refrigerator, and television.

Tools Needed for Installation

  • Cordless Drill
  • 1 3/4 Inch Hole Saw
  • Tape Measure
  • Pen or Pencil
  • Medium Phillips Head Screwdriver
  • Weatherproof Silicone
  • 120 Volt Receptacle
  • Receptacle Old or New Work Box ( as needed)
  • Receptacle Cover
  • Electrical Wire Strippers
  • 12/2 AWG Ga Wire
  • 15 Amp Flanged Inlet 125V, NEMA 5-15 Flanged RV, Shore Power Inlet Receptacle, Generator, AC Port Electric Plug for Marine, RV Electrical Connections with Waterproof Cover, 2 Pole 3-Wire (Available for PURCHASE HERE )
15Amp 125 Volt Weatherproof RV/Generator Receptacle
UL Approved and Safe for Outdoor Uses

After installation, you will also need a heavy-duty extension cord to connect your generator to the installed receptacle on your cabin or building.

Choosing Locations

Best Storage for the Generator

The best location for your generator is one that will make it convenient to use while also keeping it protected from the elements as much as possible.

We decided to store our generator inside our storage shed. The doors of the shed are about 10 feet from our cabin. Inside storage keeps the generator out of the elements and protects it against damage. With proper storage, a generator will last much longer.

The added advantage is we can prop the large double doors to the shed open and operate the generator from this location. As heavy as the generator is, it’s helpful not to have to move it every time we need to use it.


NEVER operate a generator indoors where you are living or working as carbon monoxide poisoning can occur. Always allow adequate ventilation around your generator and follow all manufacturer’s instructions for safe operation.

Best Location for the Designated Generator Recepticle

You’ll want to consider two things when deciding where on your cabin or building to install the receptacle that will run your generator:

  • Outside, the receptacle should be installed within power cord reach of where the generator will sit when in use
  • Inside, the receptacle should be positioned for the safest, most convenient use of the appliances the generator will power

We decided to position our receptacle near where we’d installed the propane heater. This spot is both safe and convenient. It is centrally located to provide heating and cooling to our sleeping and living areas.

Preparing the Outdoor Receptacle

Drilling the Hole

Using a cordless drill and a 1- 3/4 inch hole saw, drill a hole into the building where you want to insert the receptacle as pictured below. Use caution when drilling! Don’t cut through any existing wiring, plumbing, or gas lines located inside the wall.

Here’s a helpful diagram of the simple outdoor receptacle installation process.

Cutting Enough Wire

Measure the distance between the outdoor and indoor receptacles. This is usually a few inches between the outer and inner walls.

Then add an extra 12 inches or so and cut a piece of wire at this longer length.

The extra wire gives you enough to redo a connection during installation should you make a mistake. It also comes in handy if you want to make changes or additions to your receptacles later.

Once your installation is complete, the extra wire is simply tucked away inside the indoor receptacle work box.

12 Gauge Wire

Once you’ve cut the full length of wire needed, use a razor knife to remove the sheathing. Trim off any excess sheathing.

You now have three individual wires:

  • The white neutral wire,
  • The black hot wire
  • The green or plain copper grounding wire
Removing the Sheathing

Stripping the Individual Wires

Next, you need to cut away some of the colored sheathing to expose the wire. You need only enough bare wire to fit snuggly into the receptacle opening. You’ll want a good-quality Electrical Wire Stripper for this task.

Electrical Wire Stripper

The left tang of the wire stripper lists the wire gauge setting as seen below.

Gauge Settings on Wire Stripper

Insert your wire into the notch that matches the gauge of your wire (12 in this case) and squeeze the handles. This cuts through the protective outer cover without cutting through the wire itself.

While still squeezing the handles together, pull the wire stripper towards the end of the wire to remove the outer sheath.

Again, do not remove too much of the protective covering. You want just enough bare wire to fit completely into the receptacle.

Connecting the Individual Wires to the Outdoor Receptacle

Using the diagram below, note the different colors of the screws on the outdoor receptacle. This color-coding makes installation a breeze:

  • The neutral wire is white and will connect to the silver screw.
  • The hot wire is black and will connect to the black screw.
  • The green or plain copper wire is always the grounding wire, and that will connect to the green screw.

Above each of the screws is a hole where the wire is inserted, as seen in the image below. Matching the wire and screw color, simply slide the unsheathed section of the wire into the hole and hand tighten the screws.

Once all the wires have been inserted and all the screws tightened, slide the protective rubber cover provided over the entire assembly as shown below.

Rubber Cover Provided

Installing the Indoor Receptacle

Drilling the Hole

Your interior receptacle should be located in close proximity to where your outdoor receptacle was just installed.

Once you’ve decided on the location, you’ll need to install what’s known as an Old Work Box (pictured below) into the wall.

Old Work Box

Place the work box against the interior wall where you want it installed. Trace around the outer edges of the box with a pencil or pen. Using a sheetrock saw or jigsaw, cut a hole in the wall where you’ve marked.

Once again, take care not to cut into any existing wiring, plumbing, wall studs, or gas lines.

Secure the Outdoor Receptacle

Once the interior hole is cut for the old work box, you can proceed outdoors to secure the outdoor receptacle to your building.

Double-check that the rubber cap covering the wires and screws of the outdoor receptacle is securely in place. Then, insert the wiring attached to the outdoor receptacle through the hole in the wall. Secure the receptacle to the wall using silicone and screws. The silicone will ensure that the opening you cut prevents any moisture from getting inside your wall.

Installing the Indoor Receptacle (Old Work Box)

Back inside at the indoor receptacle, locate the wire that was inserted into the wall from the outdoor receptacle. Feed this wire through one of the openings in the old work box.

Once the wire is threaded into the old work box, secure the work box into the opening in the wall. Note that the work box appears to have wings in the corners with screws near them.

Once you place the old work box inside the wall, tighten the screws in a clockwise motion until they will not turn any further. This expands the “wings” to secure the box tightly to the wall.

Wiring the Indoor Receptacle

Once the work box is secured to the wall, continue to pull the electrical wire through the box.

Remember, you should have cut enough electrical wire to reach between the two receptacles and give you an extra foot or so to work with. The extra will come in handy should you need to redo a connection during installation or want to make additions later.

Using the electrical wire stripper, remove enough covering off the end of each wire to allow the bare wire to loop around the screw it will attach to as shown in the image below. This is the typical installation technique for any household receptacle.


  • The BLACK (HOT) wire connects to the BLACK or BRASS Screw
  • The WHITE (NEUTRAL) wire connects to the SILVER screw
  • The solid COPPER (GROUND) wire connects to the GREEN screw.

Use the wire strippers or small pliers to twist the end of the wire around its proper screw. Curve the wire clockwise around the screw, then tighten the screw completely. This will ensure a snug fit and a good, secure connection.

Gently place the excess length of electrical wire inside the work box. Place the receptacle cover over the opening and secure it with the screws provided. Do not to over-tighten the receptacle cover as that may cause it to crack.

Installed Indoor Receptacle and Cover

Connecting To and Starting Your Generator

Preparing Your Generator for Use

Follow the manufacturer’s instructions to prepare your generator for use. Check the fuel and oil levels and fill as needed. Always add fuel to the tank while the engine is cool and on a level, stable surface. Identify the choke and fuel valve.

Locate the Proper Receptacles

In this article, we’ve covered installing a connection for a 120v connection. Many generators provide both 120v and 240v receptacles. For our purposes here, we are plugging into only the receptacles marked 120v.

WARNING: Plugging 120v appliances into the 240v receptacle on any generator will damage the appliances and create a fire hazard. Always double-check that you are using the proper voltage when connecting any appliance or tool to your generator.

Powering Up

Begin by attaching only the female end of the heavy-duty extension cord to the newly-installed outdoor receptacle as shown below (DO NOT attach the other end of the cord to your generator yet).

Following the manufacturer’s instructions, start up your generator.

Once it is running, THEN carefully insert the male end of the extension cord into the proper 120v receptacle on the generator.

Now, inside your cabin or building, you can plug in the 120v appliance(s) you wish to power, such as a heater, refrigerator, or lamp.

If for some reason your appliance is not operating after the generator starts, you can check the Reset Button on the generator receptacle or refer to the manufacturer’s instructions for troubleshooting.

Making the Most of Your Generator

Keep in mind that the more appliances you power, the harder the generator will have to work. This will burn more fuel and shorten the run time of your generator. By limiting usage to emergency-related necessities only, it’s more likely your generator will see you through the duration of the power outage.

Turning Off Your Generator

Once power is restored, power down and unplug any appliances you have been running with the generator.

Turn off your generator, then unplug the extension cord from the generator and your cabin or building.

Examine the area around your generator to be sure there are no signs of oil or fuel leakage.

Allow the generator to cool down completely. Then, follow the manufacturer’s instructions for proper storage procedures.

With any generator, remove all fuel from the tank before storing or add a quality fuel stabilizer to prevent stale fuel. You should also check and maintain proper oil levels. Running a generator with low oil can damage it.

Finally, be sure to follow the manufacturer’s instructions for running your generator at routine intervals. Proper maintenance of your generator ensures it will be ready and able to get you through the next power-outage emergency.

We care about our readers, so please remember to proceed with caution when dealing with electricity!

If you have any questions about this article, email me at and I’ll be happy to help you out.

Content editing for this post was provided by Cheri Jones, a freelance writer and editor for hire. Learn more about her services on her website, Cheri Ann Jones.