Wall sockets are electrical fixtures within the home used to connect power cords to the home's electrical wiring system. Each wall socket, or electrical receptacle, features a female connector that is designed to accept a male plug connector. Wall sockets make it easier and safer for occupants to power appliances, and are designed to minimize the risk of electrical shock, burns, and other related dangers.
Each type of wall socket features a unique design that allows it to accept only a single type of plug. This receptacle design varies by country, where different design standards and electrical codes have resulted in a wide range of plug connectors. Wall sockets differ in the shape and quantity of plug connector pins they will accept, as well as the configuration of these pins or prongs. Some accept plugs with two prongs, while others will only accept three-pronged plugs.
Many wall sockets are polarized to make it impossible for users to plug objects in to the wall incorrectly. Polarized outlets are configured to only accept a plug in such a position that the grounding and live wires within the wall correspond to the same wires within the plug. In a simple two-pronged outlet for example, one of the plugs is designed to be wider than the other so that the plug will only fit when inserted correctly. Non-polarized wall sockets accept plugs of any configuration, and pose added risk to users.
Different types of wall sockets can be found within homes and other buildings. A single wall socket accepts only a single power cord, and is typically used for large appliances like refrigerators or washing machines. Double-gang outlets feature a pair of holes that are designed to accept up to two power cords. Four-way wall sockets can accept as many as four cords. Some modern wall sockets may also include openings for USB ports to allow users to charge phones and other electronics.
Each wall socket consists of a metal or plastic frame that fits within the surrounding drywall. This frame, or box, serves as a vessel for electrical wiring and helps to reduce the risk of electrical fires. A receptacle is connected to the wires and held within the box with screws, then a plastic or metal cover plate is fastened over top to complete the wall socket.
Many building codes have very specific requirements related to how wall sockets must be placed within a building to maximize safety. Most specify a minimum height at which these sockets must be mounted above the floor. Others require outlets to be placed at specific intervals around the room to ensure a safe and adequate power supply for the building's occupants.