Anatomy of a Wall Socket: How Do They Work?

Anatomy of a Wall Socket: How Do They Work?

If you’re reading this blog indoors, then there’s a pretty strong chance you’re within about 20 to 30 feet of a power socket located on a wall or floor around you. Wall sockets are about as normal a part of our day to day lives as electric lights, paved roads and running water. They’re found all throughout our home and some are accessed frequently while others remain essentially hidden out of sight but provide power on which you regularly depend. Outlets power everything from our lamps and light fixtures to our televisions and computers to chargers for our devices like cell phones and tablets.

However, despite the fact that outlets are such a tremendously important and integral part of our day to day life, few homeowners actually know how they work. All most people know is that you insert a plug into the holes and power flows through, but they have no idea how the power got there, how it moves into the plug itself or what actually happens inside this small unit. This blog will provide those answers and offer you a few tips to help you better understand what can happen to a plug that would make you need to replace it after a while.

How Do Plugs Power Devices?

How do wall sockets actually provide power to the devices plugged into them? To get the answer, we need to take a look at a few of the critical components found in a socket itself. First, if you pull a socket out of the wall and look at the back and sides, you’ll see either two or three wires coming from it. One wire is usually white in color, while the other is usually black, brown, gray or some other dark color. The white wire usually designates your hot wire, or the positive connection, while the dark color is your negative connection. The third wire coming from your plug could be green in color, but is most frequently unshielded or just raw wire that runs from a small hook on the bottom of the outlet. This is your ground wire and is an extremely important safety feature. Because this line is neutrally charged, it is a safe place to discharge electricity, preventing it from injuring you or damaging anything you plug into the socket.

These electrical lines are what power your socket and thus, power the devices plugged into them. However, how does the power get from these lines to your device? The answer is inside the plastic with parts that most people never see. Located inside each socket are two pairs of metal strips that are designed to bend and flex, but return to shape when the pressure on them is released. Each pair of strips is connected to one of your electrical lines (either hot or ground). The strips in each pair normally press against each other, however, when you plug something into an outlet, the prongs on each plug wedge themselves between each pair of strips. The friction between the strips and the plug is what holds the plug in place and likewise, these strips are what electricity passes through in order to reach your device. It’s incredibly simple, yet tremendously reliable and effective. If you have an outlet where anything you plug in seems to fall out with ease, the reason is probably because the strips are wearing out and simply can’t grasp your plug as easily as they once did.

Why Is One Slot On a Socket Bigger Than the Other?

If you look closely at a socket, you’ll notice that the two slots in your socket are not the same size—one hole is slightly larger than the other. This is an important safety feature. Accidentally crossing connections and connecting a hot line to a ground like and vice versa can be extremely dangerous and result in fires, sparking, severe damage to electrical components and even potentially serious injury.

To solve this problem, electrical sockets have one larger prong socket (usually on the left side of the plug) and a smaller socket (usually on the right). Some of the plugs attached to your electrical devices also have a larger prong that will only fit in the left-side hole. Because you can’t press the larger prong into the smaller socket hole, you can’t plug this device into your outlet backward. Thus, you don’t have to worry about accidentally plugging a device in the wrong way.

What about devices that have two different prongs that are the same size? These devices can be plugged in either way—they are built with reverse polarity protection components so you’re safe to plug the device in either direction.

How Do Sockets Wear Out?

Sockets are generally tremendously reliable and can last for decades without a single problem. The most common way sockets wear out and need replacing is simply because the strips that grab your plug prongs wear out and can’t keep the same grip on your prongs that they once did.

However, prongs themselves can also wear out with exposure to air. Because these are unshielded metal, they will eventually corrode, creating resistance. High resistance creates heat and heat can cause electrical fires over time. This also contributes to the occasional spark you might see when plugging a device into a particular socket.

Elsewhere On Our Blog

This month we took a look at some other high-tech home systems that could benefit you! In one blog post, we took a look at how boilers work. Boilers use the heat-carrying power of water to bring much-needed heat around your home in a way that’s safe, efficient and remarkably effective. Once the water from your boiler reaches its destination, it flows through a “radiator” system—a metal grid that radiates the heat into your room, providing you with even and dependable heating.

We also answered this important question: how exactly do solar panels change the energy from the sun into clean, usable solar power? It’s not magic and it’s not even that complicated—to put it simply, solar cells capture the power of the sun by having solar photons collide with electrons in solar cells. The resulting collision is packed with energy that your inverter can then turn into useable electricity.

Have a question about your heating, air conditioning, electrical, or solar energy system? Talk to the experts at Valley Heating, Cooling, Electrical and Solar! Contact us today to get started.