AC power plugs and sockets

A socket is used as electrical connectors between lines. The socket is either fixed to a wall (surface ) or recessed ( flush-mounted) installed, or is part of a mobile line coupling, such as a table or multiple sockets or extensions that are designed for mobile use.

A socket is mostly used for the power supply, but also for telephone and data transmission. Typically, devices with single-phase 230 V or three-phase alternating current ( three-phase ) are supplied with 400 V electrical outlets; but there are also adapter sockets for 12 V DC. Also for the supply of higher voltages and currents exist socket systems such as CHAdeMO for high-power direct current charging of electric cars or plug systems for the supply of bucket wheel excavators up to 20 kV. The connectors are standardized for ordinary, but for historical reasons, not always internationally.

A socket used for the power supply in the household (usually over junction boxes ) to a distribution of the building installation and usually results in one of three phase conductors, the neutral conductor and the protective conductor ( see also: Single-phase and three-phase alternating current).

The live outlets often are called jacks or clutch when the design "female" (the female also has inwardly facing contact openings, as in a socket). Thus, the protection against contact is ensured.

Device side connector are mounted, the design is "male" ( the contact pins facing outward ), as they become live only when connecting to a socket.

Colloquially interchanging the terms socket / connector and adapter should be avoided, even if often a movable coupling is infected as a connection cable into the device mounted to the connector.

Before the development of the first electric socket Appliances were screwed into light bulb sockets. About 1920, there was also so-called " power thieves ". These were intermediate pieces that you screwed between bulb and socket into which you could plug in most electrical devices on both sides. Since the light output was then billed a flat rate, presented this a form of theft dar.