Wylex standard consumer unit fitted with rewirable fuses

Modern Hager consumer unit fitted with MCBs and an RCD

A consumer unit is a box of fuses or breakers, usually arranged in a single row. This is unlike a distribution board which has multiple rows of fuses or breakers and usually serves two or more locations, which may be split phase, two phase, two phases taken from three phase), or three phases. Fuse Box taken by C Ford, 29 June 2004. ... Fuse Box taken by C Ford, 29 June 2004. ... Image File history File linksMetadata Download high-resolution version (2816x2112, 1076 KB) I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File linksMetadata Download high-resolution version (2816x2112, 1076 KB) I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... 200 A Industrial fuse. ... A 2 pole MCB A circuit breaker is an automatically-operated electrical switch which is designed to protect an electrical circuit from damage caused by overload or short circuit. ... A fairly standard American circuit breaker panel manufactured by General Electric and using interchangeable circuit breakers A distribution board (known in the United States as a (circuit) breaker panel, panelboard, or load center or for old ones, fuse box) is a mounting enclosure for multiple electrical circuit breakers. ... A split phase electricity distribution system is a 3-wire single-phase distribution system, commonly used in North America for single-family residential and light commercial (up to about 100 kVA) applications. ... Two-phase electrical power was used in some early 20th century factories and the distribution systems that served them. ... In electrical engineering, three-phase electric power systems have at least three conductors carrying voltage waveforms that are 2Ï€/3 radians (120°,1/3 of a cycle) offset in time. ... In electrical engineering, three-phase electric power systems have at least three conductors carrying voltage waveforms that are 2Ï€/3 radians (120°,1/3 of a cycle) offset in time. ...

A consumer unit fitted with just fuses is often referred to as a "fuse box".

The box pictured top-right is a "Wylex standard" fitted with rewirable fuses. These boxes can also be fitted with cartridge fuses or miniature circuit breakers (MCBs). This type of consumer unit was very popular in Britain until 2001 when wiring regulations mandated residual current device (RCD) protection for sockets that could "reasonably be expected to" supply outdoor equipment (BS7671:2001, ISBN 0-86341-373-0). There were a number of similar designs from other manufacturers but the wylex ones are by far the most commonly encountered and the only ones for which fuseholders/breakers are still commonly availible. A 2 pole MCB A circuit breaker is an automatically-operated electrical switch which is designed to protect an electrical circuit from damage caused by overload or short circuit. ... In electrical engineering, residual current circuit breakers (RCCB) or residual current devices (RCD) are circuit breakers that operate to disconnect their circuit whenever they detect that current leaking out of the circuit (such as current leaking to earth through a ground fault) exceeds safety limits. ...

Modern consumer units (picture bottom right) usually use DIN-rail mount breakers. Unforuntately while the rail itself and the shape of the front opening are standardized the busbar arrangements are not. Therefore mixing of brands should generally be avoided and where unavoidable care should be taken to ensure that the breaker chosen is a good fit for the busbars. Generally a "split load" arrangement is used with some circuits protected by the RCD and others not. A DIN-rail mounted telephone modem. ...