AC Power Plugs and Sockets

AC power plugs and sockets are devices that allow electrically operated devices to be connected to the primary alternating current (AC) power supply in a building. Electrical plugs and sockets differ in voltage and current rating, shape, size and type of connectors. The types used in each country are set by national standards.

Generally the plug is the movable connector attached to an electrically operated device's mains cable, and the socket is fixed on equipment or a building structure. Plugs have male circuit contacts, while sockets have female contacts. The plug has protruding prongs, blades, or pins that fit into matching slots or holes in the socket. A socket is also called a receptacle, outlet, or power point (British English). It may be surrounded by a cover called a wall plate, face plate, outlet cover, socket cover, or wall cover.

To reduce the risk of electric shock, plug and socket systems can incorporate safety features. These may include socket design intended to accept only compatible plugs inserted in the correct orientation; plugs with insulated sleeves on contact pin shanks so a partially inserted plug does not bear exposed live pins that could be touched; or sockets with blocking shutters that open only when a compatible plug is inserted. Sockets are designed to prevent exposure of bare live contacts. The exposed contacts present in some sockets are used exclusively for earthing (grounding).