domestic plugs and sockets and IEC 60906 - 1

AC power plugs and sockets

From Wikipedia, the free encyclopedia

See also: Industrial and multiphase power plugs and sockets

AC power plugs and sockets are devices for removably connecting electrically-operated devices to the commercial power supply.

An electric plug is a male electrical connector with contact prongs to connect mechanically and electrically to slots in the matching female socket.

Wall sockets (sometimes also known as power points,^[1][2] power sockets, electric receptacles, or electrical outlets) are female electrical connectors that have slots or holes which accept and deliver current to the prongs of inserted plugs. To reduce the risk of injury or death by electric shock, some plug and socket systems incorporate various safety features. Sockets are designed to accept only matching plugs and reject all others.

Contents [hide] 1 Terminology 2 The three contacts 2.1 Polarisation 3 History 3.1 Early history 3.2 Proliferation of standards 3.3 Design for safety 3.4 Consolidation of standards 3.5 World maps 4 Types in present use 4.1 Type A 4.2 Type B 4.3 Type C 4.4 Type D 4.5 Type E 4.6 Type F 4.7 Type E / F hybrid 4.8 Type G 4.9 Type H 4.10 Type I 4.11 Type J 4.12 Type K (Danish standard) and Thai 3 pin plug 4.13 Type L 4.14 Type M 5 Proposed common standard 6 Comparison of plugs 7 Multi-standard sockets 8 Adapters 9 Obsolete types 9.1 Old Spanish sockets 9.2 UK electric clock connector 9.3 American "Type I" 9.4 U.S. perpendicular outlet 9.5 U.S. Combination duplex outlet 9.6 U.K. Dorman & Smith (D&S) 9.7 U.K. Wylex Plug 9.8 Lampholder plug 9.9 Old Greek sockets 10 Unusual types 10.1 NEMA 2-15 and 2-20 10.2 Soviet adaptor plugs 10.3 U.K. Walsall Gauge plug 10.4 Italian Bticino brand Magic security connector 11 See also 12 External links 13 References

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IEC 60906-1

From Wikipedia, the free encyclopedia

IEC 60906-1 is the international standard 230 V household plug system. It was intended to become the common mains plug and socket standard, to be used one day everywhere in Europe and other regions with 230 V mains. The standard was published by the International Electrotechnical Commission in 1986. So far, only Brazil has plans to introduce it [1]. Although it looks similar to the Swiss plug, its dimensions are different.

This article is only about part one of this standard. Part two, IEC 60906-2, defines a global standard plug for 115 V mains. It is compatible with the systems used today in North America and Japan. Part three, IEC 60906-3, defines a family of extra low voltage connectors.

Contents [hide] 1 Features 2 Comparison with traditional systems 2.1 BS 1363 2.2 Schuko 2.3 Swiss plug 3 Dimensions 4 Class 0 plug and socket 5 See also 6 References 7 External links

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International standardization of electrical plugs and sockets for domestic use Introduction When the IEC was founded, in the first decade of the 20th century, its first endeavours concerned standards for electrical machinery, including the associated nomenclature and symbology. It was only after the first World War (1914-1918) that IEC’s attention turned to the newer applications of electricity and its widening use in the home and office. Early days In the early 1930s the international representation in IEC was made aware of the work going on in Europe on standardization in the field of electrical power distribution by an organization called the IFK (Internationalfragenskommission – International Questions Commission). Based in Holland, it comprised delegates from electricity suppliers (generators and distributors) and electrical test houses in 12 countries, some of whom were also representatives on IEC National Committees. At its meeting in Paris in January 1933, the Committee of Action (CA) agreed that the IFK be contacted with a view to collaboration on matters of mutual interest. At the CA’s subsequent meeting, also in Paris in October 1933, it was reported that this contact had been made and that the IFK had indicated that it was prepared to submit fundamental work, presumably in electrical standardization, to the IEC. At the next CA meeting at Prague in October 1934, it was recorded that a complete IEC/IFK agreement on co-operation had been reached and a new Technical Committee (then still known as Advisory Committee) No. 23 was created to deal specifically with the standardization of electrical fittings. The work of this committee took a long time to take off and at its meeting in Torquay, UK in June 1938, the CA urged the new TC (now with the title Electrical accessories) to hold its first meeting ‘next year, in order to consider the question of plugs and sockets’. However, at the next CA meeting, again in Paris in June 1939, nothing had yet happened within TC 23 and the CA, clearly annoyed, ‘instructed the General Secretary to invite(sic) both the Chairman, Mr. Van Staveren (the Netherlands), also President of IFK, and Secretariat (Germany) to initiate work as soon as possible and to consider the opportunity for a meeting some time in 1940’. As we are all aware, the world then fell apart with the outbreak of World War II. The start of work After the war, and its subsequent economic recession, work on domestic plugs and sockets got under way at the first meeting of TC 23 in Luzern in October 1947, still with Mr. Van Staveren in the Chair and now with a Belgian secretariat. By this time, the European work had moved to the CEE (International Commission on Rules for the Approval of Electrical Equipment) and TC 23 discussed co-operation with the CEE in the field of ‘Unification of the International Standards relating to sockets, plugs and connectors’. The CEE work led to the first edition, in 1951, of its Publication 7 which was, in essence, a selection of the most widely used plugs and sockets in Europe, excluding the UK and Ireland. The IEC as a whole, and in particular TC 23, realized that, with the proliferation of types used in Europe, and the limited prospects for any agreement even in this limited geographical region on a common standard, it was pointless to commence work at that time on an international unique standard. Therefore, the early work in TC 23 on this subject led to the eventual issue in 1957 of the first edition of IEC Publication 83, Standard for plugs and socket-outlets for domestic and similar general use. This publication was essentially a collecting together of the European plug and socket designs of CEE 7 together with those of the USA and of Great Britain, which were used in many other countries. Rather than an international standard, this publication was a catalogue of national standards, and this was recognized by giving its second edition in 1975 the status of a Technical Report. The universal plug and socket system However, it was always recognized by the IEC as a long-term objective that a truly universal system of domestic plugs and sockets should be aimed for. It was realized very early on in IEC that, even were agreement to be reached on such a standard, implementation would take decades in view of the massive investment in existing installations and the associated manufacturing plants. Serious work on this matter started in IEC in 1970 with the creation of Subcommittee 23C (Worlwide plug and socket outlet system). Earlier, TC 64 (Electrical installations) had been formed and it was inevitable that, in its considerations of domestic wiring installations, it would face the problem of the plethora of plugs and sockets in use and this provided the IEC with further impetus to find a global solution or, at least, attempt to reduce the varieties. The essence of the work concerned safety and, in particular, trying to ensure that dangerous situations could not arise during the periods when the new system and the multitude of existing ones had to exist side by side. The first drafts of a universal system considered by SC 23C proposed all flat pins and this was pursued for many years. However, at the voting stage, objections grew and, many National Committees expressed themselves more in favour of a round pin solution. The other serious problem encountered was in trying to find a unique solution for 125V and 250V distribution systems. After long, and often acrimonious, discussion, the subcommittee came to an acceptable solution which was finally formulated in 1986 as publication IEC 906-1 (now IEC 60906-1) for 250V installations using round pins and in 1992 as IEC 906-2 (now IEC 60906-2) for 125V installations using the familiar US flat pin design. More recently, in the 1990s, CENELEC, in Europe, was put under pressure by the European Commission to devise a harmonized plug and socket system for Europe. (Incredible as it may seem, there does not seem ever to have taken place, in Europe or elsewhere, an assessment, even at a superficial level, of the economic consequences of the implementation of a universal system. The view of the Commission appears to have been based entirely on political considerations!) CENELEC took as its starting point the IEC standard of 1986 and spent thousands of man-hours undertaking the almost impossible task of modifying the design with the aim of ensuring 100% risk-free operation of the system when used in conjunction with all the existing types in Europe. Naturally, apart from the technical difficulties, there was the clash of the many vested commercial and political interests and it was not surprising that, after much work and many meetings, CENELEC had to admit defeat and abandon its efforts, much to the chagrin of the Commission. However, as the IEC continues to point out, internationally agreed standards for domestic plugs and sockets for the 250V and 125V ranges DO exist and are, even today, available to any country that cares to implement them.

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