Earth leakage protection unravelled

July 28th, 2011, Published in Articles: Vector

When must an earth leakage relay be fitted?

In the 1969 amendments to the 1963 Edition of the Standard Regulations for the Wiring of Premises (the “Blue Book”) a new regulation 226 was added which read:

“Automatic earth leakage protection is mandatory in certain instances in terms of these regulations. Such automatic earth leakage protection shall in addition to any other requirements in terms of these regulations be approved.”

“Where considered necessary the engineer may specify the installation of an approved earth leakage protection device.”

Regulation 227, also a new regulation, stated:

“All installations supplied by temporary electrical supply connections such as builders and construction sites, caravan parks, amusement parks, fetes and fairs, must be protected by approved automatic earth leakage protection.”; and regulation 1302 (D) read “automatic earth leakage shall be installed forthwith on an installation upon receipt at any time of written instructions to that effect from the engineer.’’

Then in September 1974 earth leakage became mandatory on single phase and three phase socket outlets and some lighting circuits with the following exclusions:

  • Socket outlets fed from a safety supply

  • Circuits connected to an emergency lighting supply

  • Circuits from electronic dimmers in theatres, cinemas and similar places of assembly.

In the 1987 edition of SABS 0142 the code stated that an earth leakage protection device shall be provided for circuits supplying single phase socket outlets in a  new installation, and where any rewiring of, or extension to, a socket outlet circuit in an existing installation is carried out. The earth leakage protection shall be provided to the circuit so rewired or extended.

The 1993 edition confirmed the same requirements, but added a note which read:

“Certain existing socket outlets do not have earth leakage protection. In the interests of safety, such circuits should be provided with earth leakage protection.”

However, the code has always stated that “the replacement of a socket outlet is not regarded as a rewiring of or extension to an existing installation.”

In SANS 10142-1:2003 (Edition 1) it said earth leakage protection shall be provided:

  • in new installations for circuits that supply SANS 164-1 or SANS 164-2 type socket outlets,

  • in existing installations for circuits that supply socket-outlets when such circuits are rewired or extended before 1 January 2005, and

  • in existing installations for all circuits that supply socket-outlets when a Certificate of Compliance is issued from 1 January 2005.

This requirement was subsequently removed from the code.

The latest edition of the code (Edition 1.7) now states:

Except as allowed in 6.7.5.5 and 7.10.1.6, non-auto-reclosing earth leakage protection shall be provided :

  • In a new installation for circuits that supply SANS 164-1(SABS164-1) or SANS 164-2(SABS164-2) type socket-outlets

  • In an existing installation for all the circuits that supply socket-outlets where any such circuit or circuits are rewired or extended.

Note: It is recommended that earth leakage protection will be installed in all circuits that supply socket-outlets in an existing installation.

When is earth leakage protection not required (clause 6.7.5.5)?

  • Socket outlets  connected to a safety supply

  • A socket outlet that complies with SANS 164-4 (ie. a red dedicated 16 A coloured red intended only for the connection of appliances for critical application (such as emergency lighting, deep-freezes, burglar alarms or data processing equipment)

  • Circuits that supply fixed socket outlets positioned out of normal reach, rated at less than 16 A and intended for the connection of luminaires (See 6.14.1.4) and

  • A stove coupler that complies with SANS 60309 – 1.

Brian Bilton