by Mark Botha, editor
The Wiring Code (SANS 10142-1) has identified SANS 164-2 as the preferred standard for plugs and socket systems in 2013, and it is now expected that this configuration will be phased in on new installations as of next year.
The standard specifies a three-pin, hexagonal plug-and-socket configuration developed in 1986 by the International Electrotechnical Commission (IEC) for reasons of safety and to create a universal plug and socket system. It includes, among others, safety features such as a shutter, a 10 mm well and insulated plug pins to prevent live pin exposure. The configuration improves upon SANS 164-5 and SANS 164-6, which are two-pin (unearthed for class II double insulated) 2,5 and 16 A systems, the plug tops of which cannot be rewired. These plugs remain compatible with the SANS 164-3 three-pin sockets.
The current three-pin configuration, which is used only in South Africa, Zimbabwe and in parts of India, will be phased out over a period of some 20 years. This means that existing installations need not be adapted for the foreseeable future.
Industry expert Chris Yelland welcomes the move to the hexagonal configuration with its offset third earth terminal. He says it is economical and accommodates the two-pin Europlug configuration for double-insulated devices. This will eventually eliminate adaptors which Yelland describes as costly and often sub-standard. On this subject, acting ECA(SA) national director Lucas Bowles says the move will eventually lead to the demise of multi-adaptors, which are often overloaded and are known to have caused electrical fires.
To Yelland, the new configuration is also more compact than the current three-pin system – another advantage, especially in the office space. An article published in Electrical Contractor at the time of the adoption by the SABS of IEC 60906-2 in 1993 states that a 110 x 65 mm wall box can now accommodate three 16 A socket outlets.
Then South African Electrotechnical Committee (SAEC) secretary Jim Toms said in the article that the new configuration is also economical in terms of manufacture: the SANS 164-2 configuration will require only 15 mg of brass to make as opposed to 70 mg needed for the conventional system.
Crabtree technical development consultant Gian Campetti, who is also chairman of the SABS SC23B mirror committee, agrees. He says any possible initial price inflation would be due to the route-to-market process and not to manufacturing. Crabtree, for instance, had to invest in new tooling for its locally-made Slimline Compact range. He says the cost of the sockets will be “in line with current pricing” but expects the rewireable plugs to be slightly more expensive due to lower volumes initially.
Bowles says most imported appliances would be compatible with the new sockets.
In terms of safety, Yelland notes that the pins on the proferred plug are semi-insulated and cannot be touched while half-inserted into a socket. The plug is also non-rewirable, which eliminates the danger of connecting the terminals incorrectly.
Writing in 1993, Toms predicted that the new “standardised” configuration would “obviate the need for replacing plugs on imported products”. This, however, has not materialised as IEC 60906-2 has only been adopted by South Africa and in part by Brazil as a basis for its NBR 14136 in the 21 years since its publication.
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