Surge Protection in Low Voltage Electrical Installations: Risk assessment analysis for South Africa An edited publication based on a research paper by Andrew Dickson and a Research Team of the School of Electrical and Information Engineering, University of the Witwatersrand This research project was commissioned under the auspices of a Research Steering Committee of the South African Bureau of Standards November 2006 C:\Documents and Settings\SERVER\Desktop\Surge & Lightning paper - RAC Copy 21 Nov 2006.doc 2 Surge Protection in Low Voltage Electrical Installations: Risk assessment analysis for South Africa This document is a summary of the research work conducted by a research team from the University of the Witwatersrand (Wits) under the direction of an SABS research steering committee. This paper was edited from the original report provided by the Wits University research team. The Wits research team comprised: Prof. I.R. Jandrell Dr J.M. Van Coller Prof. J.P. Reynders Mr. A.S. Dickson Mr N.J. West The SABS Research and Development Steering Committee involved included: Dr F. le R. Fourie (SABS Research & Development) Mr A.J. Claasen (StanSA) Mr A. du Plessis (Chairman SANS 10142-1) Dr H. J. Geldenhuys (Eskom) Mr V. Cohen (SANS 10142-1) Mr S.J. Pretorius (Telkom) Background The wiring of most low voltage electrical installations in South Africa is governed through incorporation of the applicable standard (SANS 10142-1) into law by reference in the Electrical Installation Regulations of the Occupational Health and Safety Act (No. 85 of 1993). SANS 10142-1 was previously known as SABS 0142 and subsequently SABS 0142-1 with the first edition of SABS 0142-1 being approved in November 2001. That document included a requirement for the mandatory installation of surge protection devices to protect the installation against overvoltage surges due to switching operations or those induced by atmospheric discharges (lightning). Mainly based on the relatively low recorded lightning activity in some southern coastal regions of South Africa, a subsequent appeal resulted in this requirement being withdrawn and being made optional through the publication of amendment 1 to SANS 10142-1 in January 2003. The responsible technical committee of the SABS then directed that a research project be initiated through the Research & Development department of the SABS. An ensuing tender for the research work was awarded to the University of the Witwatersrand (Wits). The work was supported by nominated members from the SANS 10142-1 working group. The original mandate of the technical committee was to: Investigate the advisability of a requirement for compulsory surge protection in low voltage electrical installations, as defined in SANS 10142-1, with due regard of the safety of people and the cost to benefit ratio. If such protection is required, the report must also detail the type(s) of protection, the type of installation, and the locality in such installations. The research team redefined this objective: To formulate a rational approach to the application of surge protection in low voltage installations, with due regard to the safety of people, installations and equipment, and to the cost to benefit ratio.
