How To Install Electrical Service On A Tiny Home

When building, tiny house electrical questions are leap to come up. I know I had a million of them:

How does a tiny house get power?
How do I wire a tiny firm?
What kind of wire, outlets, and breakers do I demand?
How much will information technology toll to wire my tiny house?

I want to dig into a lot of these bigger questions, and so point yous to a not bad resource that goes into a ton of particular on wiring your tiny dwelling house.

NAVIGATION

How Does A Tiny Firm Get Power?

For the most part a tiny house is set up just like a regular dwelling, but some people who are more mobile opt to have a temporary connection as opposed to a permanent i. Whatever your approach, there are some technical details you need to follow.

Temporary Power Connections – l Amp Plug

This is my preferred method and how I power my tiny firm. I utilize a l-amp plug from an RV supply store for about $30, plus an extension cord that I assembled myself past purchasing the ends and wire. The wire for a fifty-amp drop cord is pretty pricey — $3 a foot if pre-made or $1.l per foot if yous do it yourself.

Essentially, this is but a behemothic outlet that pumps a lot of power through it. I've establish with my local code enforcement that if I apply this approach, it beingness "temporary" is a critical gene in being legal.

If my tiny business firm was hard wired, that would open up a huge can of worms legally speaking. Beingness that it is "temporary" by nature of the plug, building inspectors instantly lost involvement, which is exactly what I wanted.
The other benefit of this approach is that you can ringlet into most whatever RV park and plug in, which makes this a win-win in my volume.

Tiny House Power Extension Cords

If you lot're using a temporary power connection to your tiny house y'all'll demand a way to connect the firm to your power source. The simplest way to exercise this is to buy an RV ability cord. Keep in mind this needs to be sized properly to exist rubber.

Permanent Power Connection

The only real deviation here is wiring the ability line directly to the panel, without a plug. First yous need to have your ability box and power access installed and inspected. And so it comes fourth dimension to actually connect the power to your house.

This is usually done by the ability company who brings the line to your house and connects it to your ability box. The key thing to remember is that each municipality will practice this a niggling differently, and it will demand to be inspected.

The National Electric Code – NEC

The National Electrical Code is the principal code reference for you lot to refer to when it comes to all things wiring. This book is pretty dense, merely for most things, y'all'll be able to effigy out the different cardinal sections y'all need to know as you beginning to wire your tiny business firm.

Hiring an electrician is, of form, advisable to help yous go the details right, and an inspection is e'er required. Electricity in a tiny house is a large deal, as doing anything wrong can create a dangerous state of affairs that could pb to a burn down or fifty-fifty decease. Proceed at your own risk, as I'm not liable here.

Calculating Your Tiny Firm Electrical Needs

It'southward a adept idea to figure out how much power your tiny business firm will need and utilize for a couple of reasons. Commencement, you lot want to size your ability source coming into your house correctly. If you're living off the filigree, you need to make sure your solar panels for your tiny firm are sized properly. You lot also need to make certain your circuits, wires, breakers, etc. are sized properly to make sure they are safe and up to code.

The skillful news is that calculating this in a tiny house is really unproblematic. Since we're so intentional about what comes into our house and we are ofttimes designing and building the house ourselves, we know exactly what is going to get in information technology. When I was wiring my tiny house and figuring out my solar panels, I literally had a list of everything that needed power in my tiny home.

The Nuts: Amps, Volts, & Watts

I'm not going to go into a comprehensive guide to electric theory, simply there is one thing to understand that will make this all a whole lot easier:

That seems unproblematic enough, just let'south have it one pace further. If yous think dorsum to your algebra days, sometimes your teacher would give you an equation where you had to solve for 1 variable, but it required you to move it around. If y'all were solving for X, you had to manipulate the formula so X was on ane side of the equal sign and the residuum of the variables were on the other side.

You moved things around by dividing, multiplying, and so on to shift things around where you needed them. That's what nosotros need to do here in a lot of cases because we may know two parts of the equation, but not the third.
For example, if we knew the watts and the volts, merely didn't know the amps, we could do this:

Another example is if we know the watts and the amps, but needed to know the volts:

So the 1 thing that makes this so much easier is realizing that watts, amps and volts are related. The interplay between them is proportional to the others.

A practical example is if a toaster says information technology's 1200 watts and you demand to know what the amps are for some reason, nosotros tin do the math rapidly. Houses are most often 120-volt circuits (more on that below). That means we know ii variables:

1200 watts
120 volts
We need to solve for Amps

How Much Electricity Practise Items Employ

Here is a chart of common things you'll notice in your tiny house and how much power they utilize.

120 Volt Vs. 240 Volt

Much of your house in the USA is running on 120-volt circuits, but that volition vary in other countries. Also in United states houses, you will commonly find circuits that are 240-volt used for larger appliances, HVAC and other large power draws.

One thing that confused me at showtime is that sometimes people say 220 volt, 230 volt or 240 volt when talking most these types of circuits. There are technical differences, but largely they are referring to the same thing.

I say 240 volt, but what information technology really means is that instead of a single 120-volt wire going to that outlet/appliance, there are actually two 120-volt hot leads going to it. A 120-volt atomic number 82 plus another 120-volt lead adds upwards to 240 volts.

In 240-volt wires, you'll typically detect a red wire and a black wire, which are the "hot" leads. You'll also find a single white wire that is neutral and a bare copper or greenish wire that is ground.

Doing The Math

$Doing The Math$

I'd start by commencement making a full list of all the electrical items in your house (plug in and hard wired) and list them in a column on a spreadsheet. And so side by side to that cavalcade, have another column for watts, amps and volts. If y'all're wanting to implement solar ability, yous can add together an extra column for hours you'll apply each item in a day.
And then start filling in everything you know about each particular. To detect that information yous can exercise the following:

Check the label, which usually lists some of the electric numbers.
Go to the manufacturer'south website and find a spec sheet or transmission for the item.
Use a Impale-a-watt plug in meter or clamp meter to measure it directly.

Tiny House Wiring Diagram

Let's get-go out with an overview of how a tiny business firm is wired for electrical. Wiring your tiny house is dependent on your blueprint and use, simply in general, people wire their tiny house like this:

Left side of the main floor
Right side of the main floor
Loft
HVAC
Kitchen
Appliances
Other big draws

Each circuit should be designed for its expected load + 25% (equally stipulated by code). That usually means a 20-amp circuit breaker on each excursion of your house except for appliances and HVAC, as they often are large draws.

I did mine a little differently. Here is a functional diagram of how my tiny firm is wired:

Here is a layout diagram of how I placed my electrical connections when I built my tiny house. You can run across how this diagram differs from the functional diagram past showing the locations of the outlets, lights, fans and other connections. The functional diagram just shows how they're all connected.

Electrical Drawing Symbols

When reading a diagram or making your tiny firm plans, electrical symbols are autograph to know what goes where. They tin quickly tell y'all what is going on within a house.

Tiny House Electrical Materials Listing

At that place are a lot of elements that go into wiring a tiny house. Choosing the right components and connecting them correctly is key to a safe install. The NEC dictates many if non all of these considerations, and so make sure you follow those guidelines.

Here are some of the key elements and my recommendations for them:

Tiny House Electrical Console / Billow Box

The breaker box is the key hub of power for your entire tiny house. The power comes from a ability source (the grid, solar panels, etc.) and then is cleaved down into smaller runs chosen circuits. My proposition is to have at to the lowest degree ten spaces in your box for an approximately 100-amp box.

In many cases, your power visitor volition default to a 200-amp service, but you may be able to request a smaller one. Although it isn't a bad idea to have a larger service and slightly larger box than what you call up yous need in case a need pops upwardly in the future. Oftentimes the toll difference isn't a ton.

Wire For A Tiny house

The wiring for your tiny house will typically exist done with Romex (a brand proper name used broadly to draw this type of wire), besides known equally non-metallic sheathed wire that is typically used in residential wiring.

One quick point I want to make about terminology. Yous have wires and cables. Wire is a single solid copper conductor, while cable is several strands of smaller copper conductors combined into a package. For the layman, we use the word "wire" casually, simply for clarity, realize that what people oft phone call a wire is oft actually a cable.

Wire Sizing

This wire/cable comes in a variety of sizes measured in wire estimate. The thing to remember about wire gauge is the bigger the number, the smaller the wire. Typical wire sizes for residential are 14 guess, 12 gauge, and ten judge.

WIRE Gauge	RATED AMPERAGE	COMMON USES
14-2 Romex	xv A	Lighting Circuits
12-2 Romex	20 A	Lighting & Outlets, Fridge
10-2 Romex	30 A	Electric Water Heater, Baseboard Heaters
10-3 Romex	thirty A	Electrical Wearing apparel Dryer

Understanding Romex Labels

Romex as well come with different numbers of usher strands that are bundled upwards to make the wire. Typically, you'll accept Romex with 2 conductors (plus a ground conductor) or iii conductors (plus a ground usher).

The wire labels on Romex packaging are a combination of the wire approximate, followed past the number of conductors that make up the cable. For example, a cable that is made of 2 conductors (plus a ground) that are 14 gauge in size, will be labeled 14-2.

Conductor Wire Colour Coding

In most cases, wire colors are used in a standard way, but you should never assume this. Ordinarily the conductors in the wire are exactly the same, just with different colour coatings for ease of keeping track of which one is which.
The most common convention for wire color coding is the following:

Black for your hot pb
White for your neutral lead
Red for your second hot atomic number 82 in 240 volt
Bare copper or light-green for your ground

Colour Coding Exceptions

Wire colors ofttimes aren't substantially dissimilar. When you encounter a wire, they are probably washed correctly, but and so again, if you didn't wire it, yous don't actually know for sure. And then be smart.

There are other cases where the colors will exist different. The main i that comes to mind is in a three-fashion switch, it isn't uncommon to notice that the white wire is used every bit a "traveler" in the 3-way circuit and could in fact be hot. To signal this, standard practice is to wrap tape around the white wire at all the boxes to signal this, only that doesn't always happen.

If y'all know of other exceptions or tips, drop them in the comments!

Circuit Breakers

Breakers are safety devices that stop the catamenia of power when at that place is an overload or a short in the excursion. That means that they need to be sized properly for the application that they're being used for. Below is a chart to give you an idea of mutual pairings.

In my tiny house, I had a 30-amp double pole excursion breaker for my minisplit and the rest were 20-amp unmarried pole breakers.

GFCI – Basis Mistake Excursion Interrupters

Y'all're probably familiar with these because you see them in bathrooms. These are special breakers designed to finish the flow of electricity if it detects a "footing fault" in every bit little as one/40th of a second. The idea here is that in wet environments, more gamble exists. Code prescribes where these are used, so make certain to follow it.

AFCI – Arc Mistake Circuit Interrupters

This is one you might not be as familiar with, but similar to GFCI, it stops the flow of electricity when it senses an arc. Arcs tin happen from improper wiring, a nail being driven through wires, insulation being compromised, or some other consequence. These are now generally required in all bedrooms and have been shown to reduce the take a chance of house fires pretty significantly. Refer to your local codes for guidance.

Grounding A Tiny Firm

Grounding is a backup pathway for electricity to flow from the source to the basis so information technology can dissipate. You lot can ground your tiny habitation past connecting the breaker box ground bar to the trailer and to a grounding rod.

A grounding rod is a 10-foot copper rod driven into the globe with a copper conductor tied to information technology. Y'all want to make sure there is a direct flow from the footing connection at outlets to the ground bar in the breaker box, and from there to the ground rod.

As a safe measure out, we also ground the house to the trailer equally well, and then that if you're driving down the road, current tin can flow down into the trailer and either dissipate through the pes of the hitch or arc a smaller distance from the trailer to the ground.

12-Volt Wiring For A Tiny House

Many people have asked me well-nigh 12-volt wiring for a tiny house — mainly those who want to be off the grid. A lot of this comes from things y'all read on the net saying that 12-volt DC wiring is more efficient than Air conditioning power, mainly because of the need to catechumen power from DC to AC.

This is generally a bad idea. Most of the advice to do this comes from a time when inverters were not equally efficient as they are today. Solar energy has come a long way very quickly, so often articles and forum posts you've read are out of appointment. Even something as new as 6 months ago is considered out of date because of the step at which solar is improving.

The other argument for DC wiring on a 12-volt setup is that DC is more efficient in general. This is true, merely it doesn't tell the whole story. Consider that if y'all wire for 12 volt, all your appliances demand to be 12 volt. That ways the appliances you need to purchase are around 3 to v times the price, and your options are very limited.

Any inefficiencies from the DC to AC conversion process can exist overcome with the addition of an extra panel or ii to your solar array. Switching to Air-conditioning lets you have a huge range of options for a fraction of the cost of DC appliances. The costs savings alone, fifty-fifty after factoring in the price of an extra solar panel or ii, volition bosom any myths almost using DC.

So for this reason, I practice not recommend anyone wiring their house for 12-volt DC power.

How Much Does It Cost To Wire A Tiny House?

The price of wiring your tiny business firm volition generally be around $500 in materials and around $1,000-$three,000 in labor if you hire an electrician. This does non include lighting fixtures and appliances, as they have a wide range of price points.

ITEM	QUANTITY	COST EACH
Romex-250 anxiety	1	$42.65
Outlets/Switches	fifteen	$fourteen.49
Outlet/Switch Covers	fifteen	$0.49
Electrical Boxes	15	$0.68
Wire Staples – 225 pack	1	$4.83
Billow Box	one	$43.67
Breakers	10	$4.18
GFCI Breakers	two	$46.15
AFCI Breakers	1	$52.31
Led Puck Lights	3	$29.43
Bath Fan	1	$24.56
		Total $625.31

Your Plow!

What's your plan for wiring your tiny house?
Are you going to be on the filigree or off the grid?

By on October 20, 2020 / Tiny House