When surge arresters fail


Research into the catastrophic failures of the gapped silicone carbide (SiC) and Metal Oxide Varistor (MOV) in the Kenyan power utility, highlights the strategic role of surge arresters in power systems. Suggestions to ensure that surge arresters are not neglected include:

  • Having surge arresters in the system tested and a record created for the basis of continuous monitoring of the trend and replacement of deteriorated pieces.
  • Re-assessing the insulation coordination of the installed equipment to ensure surge arresters are properly rated.
  • Carrying out a simulation study to verify the adequacy and appropriateness of surge arrester location in the system.
  • Revising the standards for surge arresters.
  • Companies driving a policy for uniformity across a system on surge arrester maintenance, commissioning and retirement procedures.


Take note

  • Surge arresters can and do fail.
  • Surge arresters must be carefully selected and once installed, should be checked and tested.
  • Systems should be evaluated to ensure that the installed surge arresters are the correct ones.


Published as:

Are surge arresters important in power systems? The story of neglected equipment

By E Bosire and A Yarrow, Kenya Power and Lighting Company

Electricity+Control, October 2011 (pgs 22 – 27)

Email: enockbos@gmail.com or aliyarrow@yahoo.com