Wiring,

How to Run Electrical Wire in a Mobile Home

In this article, I will teach you how to run electrical wires in a mobile home in detail.

Electrical wiring inside a mobile home is like regular house wiring, from the panel to the switches and outlets. Externally, mobile homes usually have crawl spaces underneath, making them ideal for running electrical wires outside. It’s an excellent way to power your mobile home while keeping your electrical system secured and concealed.

In general, you can run electrical wires under your mobile home with the following steps:

  • Map out the wiring path and drill holes as necessary.
  • Feed the wires through all the switches and outlets and wire them.
  • Wire the main panel.
  • Wire outside to the service equipment and grounding.

We’ll go into more detail below in 2 parts: internal and external wiring.

Part I: Running Electrical Wires inside a Mobile Home

The first part of running electrical wires in a mobile home applies to internal wiring, i.e., inside the home.

It covers the wiring from the main panel to all the switches and outlets inside. I will cover it briefly because it is like how you would wire inside a house.

Step 1: Decide the Wiring Path

Decide where you want to run the wires.

The layout of your mobile home may determine it or give options, including the location of your electrical outlets and which option you take will be your preference.

Step 2: Drill Holes

Drill holes as necessary through the studs.

Step 3: Feed the Wires Through

Feed the wires through the holes you created.

Step 4: Install the Switches and Outlets

You must install the switch and outlet boxes where you want them before feeding the wires through them, ready for wiring later.

A closer view of an installed outlet and the wires fed through it.

Step 5: Wire the Switches and Outlets

Connect the wires to the switches and outlets as normal household wiring.

Step 6: The Main Panel

The main breaker panel is the endpoint for all the internal wiring. From here, we will run a supply cable from outside the mobile home.


Part II: Running Electrical Wiresoutside a Mobile Home

The second part of running electrical wires in a mobile home applies to external wiring, i.e., outside the home. It covers the wiring from the main panel to the service equipment outside.

Power Supply (Feeder Circuit)

The NEC code (550.10a) requires the power supply to be “a feed circuit consisting of not more than one 50-A rated approved mobile home supply cord, or that feeder circuit could be a permanently installed circuit of fixed wiring”. (Hartwell et al., 2017)

Also, the service equipment for the feeder must be located adjacent to the mobile home. It can be either a breaker type or fused and must have no more than 50-A overcurrent protection.

Grounding

The grounding arrangement for mobile homes is as follows:

  • The neutral (white) conductor must be run from the insulated busbar in the mobile home panel to the service-entrance equipment and connected to the terminal where it connects with the grounding electrode conductor.
  • The ground (green) conductor must be run from the grounding bus in the panel to the neutral conductor, where it connects to the grounding electrode conductor.

The two grounding components (neutral and ground) must be kept separate inside the mobile home structure. The grounding conductor’s grounding connects to the grounded circuit conductor, i.e., the neutral, outside the mobile home on the supply side of the means for service disconnection.

A diagram showing the wiring distance of a power supply and a mobile home
[Hartwell et al., 2017]

Running Wires Outside Option 1: Along a Trench

Two solutions for running electrical wires outside the mobile home may be possible: a trench and surface wiring.

It can be easier to hide the wiring if your mobile home has a crawl space under it. You can then run the electrical wires within it.

Digging a trench is not always possible unless your mobile home will remain in one place for a long time, and there are no restrictions on digging. You might even be lucky to be over an already dug trench or a trench-like structure, in which case you can skip Step 1.

Digging a trench for a mobile home

After deciding on a location, dig a trench at least 6 inches deep with a shovel or post-hole digger.

You may need to descend a few feet if the ground is rocky and hard. When the trench is complete, it’s time to lay the conduit and wires. Hire a professional electrician if you are unsure about doing it yourself.

Position the PVC conduit inside the trench.

That is where you’ll be running your wires through. I recommend using a PVC conduit rather than just burying your wire directly without protection from water, gas, oil, and animals that could enter the crawl space under your mobile home.

Run the wires through the PVC conduit in the trench to settle it below the surface.

Having done that, you won’t have a hard time laying down concrete or asphalt afterward to conceal the wires permanently (if allowed).

After that, you must cover the conduit with dirt and repeat the process for each area you want to power.

Running Wires Outside – Option 2: Surface Wiring

You can use surface wiring if you can’t find a suitable crawlspace for your electrical wires, and digging a trench is impossible.

In that case, you’ll run the electrical wires on the external face of your mobile home and plug everything into an electric box. It will allow you to manage where and how much electricity is distributed. Although it will be visible, it will also be easy to fix a problem if something goes wrong with the wiring. Ensure there is no clear path for water to trickle down and damage the electrical wires and connections.

I only recommend this alternative for those willing to take on some additional responsibility to gain more control over their electrical wiring system. It’s not as simple as running wires underneath the house, but it could save you money in the long run due to easier maintenance!


Safety Precautions when Wiring Under a Mobile Home

When running electrical wires under your mobile home, take note of the following:

  • You should not begin until you have determined whether or not you are permitted to do so. Many states require that you acquire a permit before making any changes or working on your electrical wiring. In some cases, a professional electrician will be required.
  • Always turn off the main circuit panel before working on your electrical wiring. Go to the circuit breaker box in your mobile home. Locate the switch for the circuit you will work on and turn its power off. It’s best to turn off all electrical power in the circuit breaker box and connect a test light or a sound-producing device to verify it’s off.
  • When you run electrical wires, they must be insulated.
    • PVC conduit is an excellent alternative to copper or aluminum pipes for this process. It provides excellent insulation and will not rust over time like metal.
  • You should ensure that the electrical wires are grounded, which means they are in contact with the earth at all times, not just during a power surge or a lightning strike.
  • An exposed wire can cause a fire or a shock, causing damage to the electrical system and local wiring.
    • To avoid such issues, you must turn off the electrical circuit panel and hire a licensed electrician to repair it.
    • You can also get specific recommendations from the mobile home manufacturer, as they should have a set of rules for you to follow.

More about the Mobile Home Feeder Cable

A set of stripped wires

The mobile home feeder cable has 4 wires for supplying 100 amps to a mobile home.

It’s usually labeled s “2-2-2-4 Mobile Home Feeder” and is either copper (ideal) or aluminum (cheaper alternative). The wires are typically 2 hot ones (2-gauge), one neutral (2-gauge), and one ground (4-gauge). Mobile home feeder cables don’t have an outer sheath because they are designed to be buried for direct contact with the earth.


FAQs

What are the advantages of running wires under your mobile home? 

The benefits of wiring under mobile homes include:

  • It’s frequently less expensive than traditional wiring. It is because you are not paying someone else to do the work; instead, you can do it yourself with a little time and effort.
  • Adding outlets and switches can be much easier when wires run beneath your house. It may come in handy if you decide to make changes or additions to your electrical power system.
  • You’ll have peace of mind as everything is installed correctly and meets all safety guidelines. 

Is it possible to run Romex underneath mobile homes?

Two rolls of Romex wires

No, because Romex isn’t designed to be installed underground. However, you can use it inside your mobile home under an eve, but it should never come into direct contact with water, gas, or oil. It is not permitted because it would necessitate the installation of electrical wires outside your home and back inside, which would be time-consuming and potentially dangerous if not done correctly.

Is exposed wiring under my mobile home required to be in a conduit?

Any wiring beneath your mobile home must be completely enclosed in a conduit. Mobile home environments are frequently wet, which increases the risk of unprotected wiring. Also, any animals that enter your crawl space may cause damage to any mobile home wiring that is not protected by a conduit. Moreover, to meet building codes, your under-home wiring must be run through a conduit to prevent severe damage, loss of service, or an electrical fire.

Do I need to secure the conduit to my mobile home’s bottom frame?

Any electrical wiring beneath mobile homes must be contained within a conduit and tightly secured to your home’s frame. Install the conduit along a beam under your house and connect it to the frame at regular intervals with U-shaped brackets. If your conduit is not attached to your home’s frame, you must bury it at least 18 inches underground. However, securing the conduit to the bottom of the house is much easier and better.


References

Websites Resources:

Books:

  • Hartwell, Frederic P.; Joseph F. McPartland & Brian J. McPartland. McGraw-Hill’s National Electrical Code 2017 handbook. 29th edition. McGraw-Hill. 2017.

Video References:

Farmlife: RMSpeltz Farm – ReefDVMs

David Berquist

How helpful was this article?

Were Sorry This Was Not Helpful!

Let us improve this post!

Please Tell Us How We Can Improve This Article.

About Sam Orlovsky

AvatarCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

| Reach Me

Leave a Comment