Humans can’t survive without shelter, but modern humans in first world countries can’t survive without shelter that has electricity. Yet, despite our heavy reliance on electric lights, temperature control, kitchen appliances and the like, most homeowners know next to nothing about how their home electrical system works — or even what each component is called.
As one of the most critical systems in the home, the electrical system deserves more attention. To that end, here is a guide to the most important parts of a standard home electrical system — what they look like, what they do and how to maintain them.
Electrical Service Connection and Meter
Electrical lines might connect to your home overhead, through above-ground power lines, or your neighborhood might have buried power lines, which tend to be safer and more secure. You can read about that issue here – (Electric users ask: Why not put power lines underground?)
In either case, electricity comes into your home through the service connection and meter, which is typically a round device surrounded in thick, clear plastic. The meter records how much electricity your home uses, so you can be charged correctly on your energy bill.
From there, electricity travels through a disconnect switch, which is mounted outside the main service panel and near the meter. Any time you need to turn off all electricity to your home — like if you are experiencing a flood or if you need to perform electrical work — you should do so with this switch. However, some homes don’t have a disconnect switch, which means you’ll need to control power using the main service panel.
Main Service Panel
The main service panel is the big, rectangular metal box mounted on a wall inside or outside your home. This box is also often called the breaker box, and it should be filled with black switches called breakers, which control different circuits of electricity in your home. Breakers help your home maintain electrical safety by controlling how much electricity flows to different devices, outlets and switches; without breakers to interrupt when circuits get overloaded, your home could sustain serious damage through electrocution or fire.
Older homes might have fuses instead of breakers, but this is an outdated safety system that you should consider updating. You can read why here – (Buying a house with a fuse panel? Here’s what you should know).
Regardless of whether you have breakers or fuses, you should be extremely cautious when opening and using the panel; the wires behind the face plate are always live and carrying a significant current of electricity, which could kill you if they are improperly handled.
Near the top of the panel you should find your main circuit breaker, which controls all the electrical circuits in your home. It is likely larger than the other breaker switches, making it easier to identify. You can use this switch to turn electricity on and off if your home lacks a separate disconnect switch.
The other switches in the service panel are called branch breakers, and they control smaller sections of your home. You might want to experiment with these breakers, testing which devices, outlets and switches each breaker runs, so you don’t have to turn off all power to your house if you are only working on a small section. As best you can, label each breaker in the box.
If you were to open up your walls and pull out your electrical wiring, you would find a single plastic-sheathed cable. That plastic sheath ensures that the wires stay together in an easy-to-locate package, and it prevents electrical current from arcing and causing fire or electrocution.
If you peel back the sheath, you will find three separate wires: a black-sheathed wire, a white-sheathed wire, and a bare wire. The black wire is hot, meaning it is carrying electrical current from the power lines. If you touch a live wire, you will receive a dangerous shock. The white wire is neutral; it is used to carry the current back to the breaker panel to complete the electrical circuit. You can still be shocked with this wire, so be careful with it. The final, bare wire is the ground, which carries any excess electrical energy into the Earth to protect against electrical shock.
Modern homes should have copper wire, which conducts electricity especially well. However, older homes — especially those built between 1960 and 1980 — might have aluminum wiring, due to a copper strike and shortage during the middle of the 20th century. Aluminum wiring isn’t ideal because aluminum is much more malleable than copper; over time, it compresses, leaving gaps that produce electricity arcs. If you have aluminum wiring in your home, you should read about the dangers here – (The Fire Dangers of Aluminum Wiring)
Devices, Outlets and Switches
Finally, after traveling all this way, electricity finally reaches the electrical devices, outlets and switches that you interact with in your home. However, using these safely isn’t always intuitive; you should read up on home electrical safety here – (AHS.com).
You need electricity to survive in the modern world, but having electricity without interruption depends on you understanding and properly maintaining your home’s electrical system. Now that you know a bit more about the path of electricity through your home, you can start taking steps to making it as safe and secure as possible.