Ring circuit

A ring circuit , also known as Ring Final Circuit referred, German mutatis mutandis annular current distribution , is in the United Kingdom spread electrical installation . In the context of the low-voltage networks, it is used to supply electricity to households, apartment buildings and smaller businesses. The structure is specified by the British Standards as part of the BS 1363 standard and is heavily influenced by the use of British sockets .

history

Connection of a ring circuit with seven wall sockets

The ring circuit was developed in Great Britain between 1942 and 1947. This type of electrical installation is not common in other countries such as Germany.

The ring circuit was motivated by the shortage of copper for electrical wiring after World War II . By using a ring between the distributor ( consumer unit ) and the individual electrical connections, smaller conductor cross-sections than with the star-shaped installation could be used with the same electrical power. Disadvantages are the higher installation costs associated with the ring installation and, if the ring is interrupted, the risk of thermal overload.

In older distribution of the ring circuit even be repairable fuses (Engl. Rewireable fuses ) used where the user is in the blown fuse elements of the fuse wire "patch" had. This safety-critical system was originally caused by the shortage of materials and is consistently replaced by miniature circuit breakers in new installations .

construction

Two lines leave the distribution box per circuit, which are connected to form a closed ring. The individual wall sockets, possibly distributed over several rooms, are connected to this as shown in the adjacent sketch. Branch lines within the ring, especially with subsequent extensions, are common.

In smaller rings, conductor cross-sections of 1.5 mm ² with a fuse protection of 30 A or 32 A are common; in newer and larger rings, cable cross-sections of 2.5 mm ² are also used. The wall sockets according to British standard BS 1363 can be switched off individually and the plugs are protected by an internal fuse of 13 A.

Individual evidence

↑ Malcolm Mullins: The origin of the BS 1363 plug and socket outlet system ( Memento of December 27, 2008 in the Internet Archive ). IEE Wiring Matters, 2006. (Eng.)
^ DWM Latimer: History of the 13 amp plug and the ring circuit . Presentation papers from a public meeting to discuss the issue of ring circuits ( Memento from October 15, 2009 in the Internet Archive ), The Institution of Engineering and Technology, London, October 2007 (PDF in ZIP), (Engl.)

[1] Malcolm Mullins: The origin of the BS 1363 plug and socket outlet system ( Memento of December 27, 2008 in the Internet Archive ). IEE Wiring Matters, 2006. (Eng.)

[latimer-2] DWM Latimer: History of the 13 amp plug and the ring circuit . Presentation papers from a public meeting to discuss the issue of ring circuits ( Memento from October 15, 2009 in the Internet Archive ), The Institution of Engineering and Technology, London, October 2007 (PDF in ZIP), (Engl.)