What the Heck Is My Electrician Talking About?! Learn The Basics Of Your Home’s Electrical Service —BYHYU 239
In the last episode we had a brief overview of the rough-in phase of construction, including what goes on during the electrical rough-in. I hope you remember that during the electrical rough-in the electrical panel is installed. The electrical panel is also called the breaker panel, the circuit box or the breaker box. It’s that gray metal box with a door found somewhere in or outside of your house and it's where your circuit breakers are located. The circuit breakers are those black switches within the breaker box.
This week I’ll give you some very basic information about your breaker box and where you should locate it. Plus we’ll briefly cover when you’ll need a typical 120 volt electrical outlet versus a more powerful 240 volt outlet. And we’ll end the mini lesson with some talk about
what size electrical service/number of amps your house should have. I know this sounds pretty technical, but these are things we need to understand on a basic level so when our electrician asks if we want a 120 volt or 240 volt outlet, or if we want a 200 or 240 amp electrical service, we’ll have some idea of what he’s talking about. As always, I’ll break things down into simple terms.
Let’s start this mini lesson by defining pro terms.
PRO TERMS: Circuit and Circuit Breaker
A circuit is simply a path along which electricity travels.
A circuit breaker is a safety switch that automatically shuts off power to a specific part of the home when the electrical circuit overloads. In other words, a circuit breaker literally breaks or trips the electrical circuit when an unsafe amount of electricity surges through the pathway.
A circuit, the electrical pathway, is designed to carry a certain amount of electricity. If the electrical load grows too large for the circuit, the circuit breaker shuts off the electricity in that particular circuit. Another way of saying that is the circuit breaker limits the amount of electrical power moving through the home’s circuits. And that’s a good thing because if more electrical power goes through a circuit than it’s designed for, the home’s electrical wiring can be damaged or a worse, a fire could start.
In contrast to a light switch which you can manually control, a circuit breaker automatically and immediately shuts off the power to a specific circuit. You’ve experienced a tripped circuit like this if, for example, you were using your blow dryer, while the TV and the microwave were running at the same time. Even if they were all plugged into different outlets, they could be on the same circuit causing electrical overload and sudden loss of power to the appliances. Having too many devices plugged into one circuit is a common cause of a tripped circuit breaker. And again, we’re talking about one circuit, which might be connected to more than one outlet.
After the a circuit breaker is tripped, here’s what you do:
Homes have many circuit breakers, and they all live together in the electrical panel or the breaker box— the “brain” of your home’s electrical system. Within the electrical panel, there is a main circuit breaker that controls the power to the entire house.
You’ll also see individual breakers and each one is responsible for electricity to a specific part of your home. Make sure that you and your electrician label each breaker indicating what area of the house it controls. Avoid using shorthand or nicknames. The labels should be clear to someone who doesn’t live in the house or to the next homeowner, if you ever move. For example, a label that says “Mike’s bedroom” doesn’t mean much to an electrician or new homeowner. Instead the labels should read something like “second floor east bedroom.”
By the way, some older homes have fuses instead of breakers. Instead of breaker switches on the electrical panel, there will be screw-in fuses. But since we’re building new homes, we’ll have breaker switches.
Okay, now that we understand breakers and breaker boxes, let’s dive a little bit deeper. The power to our houses comes through an electrical meter found outdoors that the local utility company will install. That meter routes power to the electrical panel for your house.
What is the life expectancy of an electrical panel?
Many people think that the electrical panel will last as long as the house does, but that’s not always true. The lifespan of an electrical panel varies quite a bit from about 20-50 years. Dust and frequent electrical surges can decrease the lifespan of your electrical panel.
Alright, let’s talk about where to locate the electrical panel or breaker box. Most homes only have one breaker box. As a homeowner, you can’t put your breaker box just anywhere you want, but you can have some input about its location.
The National Fire Protection Association publishes the National Electric Code which gives some guidelines about where the electrical panel can be located. According to the National Electric Code, the space immediately in front of the box must be clear and the box must be easily accessible.
There must be 36 inches of clear space in front of the box. The panel should be installed at least 4 feet off the floor, but cannot be higher than about 6 feet. You need to also allow for the panel door to open at least 90 degrees, so that the door and the panel box can make an L shape when the door of the box is open.
You should locate the breaker box near your electrical meter which is on the outside of your house. So keep that in mind when the utility company or builder asks you where you want your meter because that will determine where you breaker box will go. For my house, the meter is just outside the garage, so our breaker box will be inside our garage.
Most homeowners want the breaker box in an out of the way area, but the box should not be in cramped spaces like small closets and should not go in bathrooms.
Some common areas where you can put your electrical panel that could meet all the requirements are:
Although not ideal, an electrical panel can also be installed in main areas of the house or outdoors if more commonly used locations are not available. Locating the breaker box in the attic is not recommended.
Alright, let’s transition to very quickly talk about the 2 most common types of electrical outlets in a home: 120 volt outlets and 240 volt outlets. 120 volt outlets typically look like the standard outlets you see around most homes. Compared to standard 120 volt receptacles, 240 volt outlets are larger and more industrial looking, with rounded tops, and three or four holes depending on the age of the outlet. Old school 240 volt outlets have 3 holes for a 3 prong plug, but most modern 240 volt outlets have 4 holes.
Most small appliances and electronics require only a 120 volt outlet, but a number of larger appliances need more than 120 volts of electricity to work reliably. Large, motor-driven appliances run more efficiently with a 240 volt power supply. So what appliances usually require 240 volt outlets? Electric appliances like:
Most of these larger appliances will technically run on 120V, but they won’t be nearly as effective or efficient. An oven, for example, that is connected to a 120V outlet will produce much less heat than it would produce if connected to a 240 volt outlet.
Because not appliances have the same outlet requirements, planning the exact locations of those larger appliances is important to determine before the electrician does the electrical rough-in. You need to know exactly where your stove and dryer will be located in order to ensure that your wiring is adequate for optimum function.
SIZE OF YOUR ELECTRICAL SERVICE
Finally, let’s talk about the size of the electrical service you should consider for your new build. The size of your electrical service will determine how many electrical appliances or fixtures can run at the same time without tripping a circuit breaker.
If your home will be all electric, you will need a larger electrical service and circuit breaker panel as compared to a house that will be powered by combination of electricity and gas.
The types of appliances you’ll use will help determine the size of your electrical service and circuit breaker panel. Computers and LED lights need very little power, but as we just talked about, things like electric ranges, electric clothes dryers and electric heatinG and air conditioning require a lot of power.
For most of us, the electricity delivered to our homes comes from the electrical utility company. The first stop for the electricity once it enters your home is the electrical panel or breaker box that we’ve been talking about. A home’s electrical service has a predetermined total available capacity measured in amps.
The electrical panel or breaker box is the distribution center that divides the electricity coming into the home into individual branch circuits. Remember, a circuit is simply a path along which electricity travels. Those circuits run through your home to power the lights, outlets, and individual appliances.
Amps or amperage is the measurement of the volume of electricity flowing through the wires. Most homes need an electrical service between 100 to 200 amps. Unless you’re building a very small house, the standard new build will need a 200 amp service. Rarely, up to 400 amps is used a very large home with extensive electric heating systems.
The size of your electrical service or the number of amps your house should have is something you and your electrician will need to decide based on the number of electrical appliances, electronics, lights, and electrical outlets in your house.
When an electrician computes the necessary size for electrical service of a new house he calculates the total demand of all appliances and fixtures, then sizes the electrical service to provide a comfortable margin. The calculations are fairly complex, so most electricians use a calculator tool to properly size the main electrical service. If you’re interested in trying to work through the calculation yourself, you can click this link to a site that will walk you through the calculation.
I was advised by a builder a long time ago to tell the electrician that we want enough power to have a party in the dead of summer with air conditioner on full blast and with most of the lights and appliances running, and have a DJ there with all of his equipment without tripping a circuit.
Let the electrician do the calculation and strongly consider his recommendation. But here are some general guidelines:
So that was our electrical mini lesson. Let’s see how much you learned and review some of the main concepts with a couple of quiz questions:
1. True or False: A circuit is a path along which electricity travels. And a circuit breaker is a safety switch that automatically shuts off power to a specific part of the home when the electrical circuit overloads.
2. True or False: Most small kitchen appliances like blenders and toasters require a 240 volt outlet.
That’s false. Most appliances in the home require only a 120 volt outlet, the most common type of outlets seen in a home. Some large appliances that need a lot of power such as ovens, ranges, or cooktops, clothes dryers, water heaters, electric car chargers require 240 volts outlets. It’s important to plan out where those large power hungry appliances will go in advance so your electrician can install the appropriate outlets.
3. True or False: An 800 sq ft home with a pellet stove for heating and is likely to require a 300 amp electrical panel.
That’s false. Small homes can usually get away with an electrical panel of 100 amps or even less. As a general rule, most modern, average sized homes will need a 200 amp service. Greater than 200 amps is sometimes needed for some homes larger than 4000 sq ft, particularly if it has an electric HVAC system.
Please remember that the purpose of this podcast is simply to educate and inform. It is not a substitute for professional advice. The information that you hear is based the only on the opinions, research and experiences of my guests and myself. That information might be incomplete and it’s subject to change, so it may not apply to your project. In addition, building codes and requirements vary from region to region, so always consult a professional about specific recommendations for your home.
Thanks for stopping by. I hope you learned as much as I did.