Electricity 101: Basics for New Homeowners
It’s easy to take electricity for granted. Most of the time, our biggest concern is finding an open outlet to recharge a phone or plug in a lamp. But if you’re planning to buy a home, it’s time to learn the basics of how residential electrical systems operate and connect to the local power grid.
Depending on where you live, your power lines may run overhead or underground. An electric meter is mounted at the point where power enters your home. It measures how much electricity you use and how much you will be charged each month. Newer digital meters are often read remotely.
The entrance point is also a dividing line between responsibilities. Everything leading up to your house, called the line portion, is your power utility’s responsibility. Beyond that, you must maintain everything on the “load side” within your home.
Many homes also have a main disconnect switch near the electric meter that can cut off power to the entire home without entering the house.
Main Service Panel
Before electricity is distributed throughout your home, the main power line enters a service panel—often called the breaker box or circuit breaker panel. The service panel includes a main circuit breaker and individual breakers that control power to different parts of the house.
The breaker box is usually a grey metal box mounted on the interior side of an exterior wall, close to the access point for the power line feeding the property. It may be located in a utility area, a garage, or even a closet.
You can often determine the size of your service by looking for the number printed on the main breaker switch. Most modern homes have 200-amp service and one circuit panel, while larger homes or houses enlarged with additions may have “subpanels” that serve specific areas of the home.
Older or historic homes may have smaller 100- or 150-amp services and may use more than one breaker box. Older homes may also rely on fuses instead of breakers mounted within one or more fuse boxes.
Circuit breakers and fuses prevent electrical problems, like overloading circuits or dangerous wiring flaws.
Wires run throughout your home—inside walls, under floors, and above the ceiling. They must be housed within an electrical box wherever connections occur. The most common types include:
Outlets, also called receptacles, deliver power to plug-in devices and appliances. If the outlet is located in a potentially wet area, it will include a ground-fault circuit-interrupter (GFCI).
Switches open and close circuits and are used to turn lights and fans on and off. Some switches include dimmers.
Fixtures deliver power to wall- and ceiling-mounted lights and fans. They are typically controlled by a nearby wall switch but may operate from a pull chain.
Modern building codes nearly always require that wires be connected within an electrical box made of metal or plastic. You’ll typically find at least one “hot” wire within these boxes which carries the power, and another “neutral” wire that completes the circuit back to the breaker box. There may also be a grounding wire.
While most residential electrical systems are built on these basic components, it’s essential to understand that the electricity running through your home is both powerful and potentially dangerous. Don’t attempt DIY electrical projects unless you’ve learned more about wiring and how to execute each step safely.