Arc flash protection study – Eskom’s Kendal Power Station

By L Dlamini, TFMC

 

Published in:

Electricity+Control, September 2013 (pages 22 – 24)

Enquiries: Tel. 031 450 6902 or email dlaminil@tfmc.co.za

 

The full article on Arc flash protection study - Eskom's Kendal Power Station can be downloaded in PDF format.

 

The MV and LV switchgear at Eskom’s Kendal Power Station is an older generation, designed and installed in the 1980s and not capable of containing or diverting an explosion.

This is the case in many installations elsewhere around the country including municipalities, information and communication technologies (ICT) facilities and even some large corporate buildings. In these, non-arc-proof switchgear - arc propagates waves radially around the source, with the obvious distortion effects due to reflection, refraction as it passes from one medium to another. Internal arc-proof switchgear, on the contrary, is designed to divert the explosion in a safe direction away from personnel, usually upwards.

The ultimate solution is to divert the arc away from the position where personnel would normally be when they do their routine duties of operating and maintenance. The damage has to be contained within the boundaries of the substation while venting out the pressure to minimise the damage. Only recently, manufacturers - such as ABB, Alstom, GEC and Siemens - are offering a range of switchgear that is capable of diverting an explosion in the event of an internal fault. Kendal Power Station took up the challenge with great success.

A successful roll-out of a safety concept is easily measured in compliance which is subject to audits and in auditable records of awareness training interventions, which is a requirement in the OSHA, Section 13 (Duty to Inform), paragraph (a).

 

Take note

  • PPE is there for a reason – use it.
  • Arc flash risk exists on all plant, and at all voltage levels.
  • The key to plant safety is an effective maintenance strategy.