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.