BusinessTech - Jan Vermeulen 28 April 2019.
Two new standards that extend South Africa’s plug and socket specification are being added to the country’s wiring code.
Gianfranco Campetti, the chair of the SC23B mirror committee at the South African Bureau of Standards (SABS), said the new wiring code should be published by the end of 2019.
The term “dedicated” means a plug that can only be inserted into a specific socket. “Partially-dedicated” means a plug that can be inserted into a special socket and a standard socket.
An example of partially-dedicated plugs and sockets is “red power”, where the top of the earth pin on South Africa’s old large-pronged triangular standard is flattened. Plugs that comply with this standard are coloured red.
Prior to the new standards published last year, South Africa had a standard for fully dedicated plugs and sockets. This required that the earth pin be flattened and rotated to one side. Blue plugs are rotated 53° clockwise, while black plugs are rotated 53° counter-clockwise.
According to the Digital Museum of Plugs and Sockets, red plugs may be used for electronic equipment as red sockets are connected to a safe electrical network, independent of the standard power supply.
Blue plugs and sockets indicate a connection to an uninterrupted power supply. Black sockets and plugs are for an isolated power supply with a clean earth connection, which may run through a 1:1 isolating transformer.
Dedicated and partially-dedicated plugs
The examples above of dedicated and partially-dedicated plugs and sockets are based on the standard that is currently widely used around South Africa – where three fat pins are arranged in a triangle.
South Africa also adopted a new international plug standard many years ago, and in 2018 the SABS approved amendments to the wiring code which made the new standard – called the ZA Plug – mandatory for new installations.
The ZA Plug consists of three thin pins – similar in design to the two-prong Europlug standard South Africans currently use.
SANS 164–2–1 and SANS 164–2–2, the two new standards that are being added to the wiring code this year, are based on the ZA Plug.
This means that plugs that comply with the new partially-dedicated standard, SANS 164–2–1, will be able to plug into ZA Plug sockets.
Campetti said that neither of the two newer standards would be mandatory, but will add to the current dedicated plug and socket system, SANS 164–4, which defines the specifications for red, blue, and black plugs and sockets.
SAFEhouse, a local electrical industry association, published a graphic which illustrates what the new dedicated and partially-dedicated plugs and sockets will look like. These are embedded below.
It said the new standards specify 12 dedicated configurations to allow for non-standard circuits, for defined and special applications.