Arc flash: a risk assessment and mitigation strategy*
D. Norton A and D. Wright ASinclair Knight Merz.
The APPEA Journal 51(2) 737-737 https://doi.org/10.1071/AJ10117
Published: 2011
Abstract
Oil and gas facility managers are well aware that attention to detail saves lives and supports business continuity and reputation. Those tasked with stewardship of electrical assets will be aware of the need to protect their employees from the hazard of electrical arc flash and that it should be at the forefront of safety thinking. Complacency and lack of duty of care with this real and possibly un-quantified hazard can lead to fatalities.
The primary solution to arc flash consequences in older installations has been the implementation of safe work procedures and personal protective equipment. While still valid, these solutions are the least effective options in the hierarchy of controls. SKM have developed a practical risk mitigation strategy that considers the hazards of prospective arc flash energy together with the cumulative effect of switchboard age, design, capability and condition.
The strategy also considers the range of potential mitigation controls available through the mechanism of substitution and engineering design that focuses on reducing:
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The likelihood of an arc flash incident occurring;
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The likelihood of personnel exposure; and,
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The energy released should an incident occur.
A structured arc flash risk assessment process can provide the asset owner the opportunity to rank individual switchboards for likelihood, consequence and risk, and thus provide direction for engineered remediation and capital expenditure. SKM proposes the way in which arc flash risk can be assessed, how appropriate layered mitigation measures might be selected, and how an asset owner may approach the issue of arc flash hazard mitigation to economically and reliably protect its employees.
Danny Norton has over 30 years’ experience in electrical power engineering within Australasia. His career responsibilities have included investigation and planning, detailed design, specification, works inspection, construction supervision, testing/commissioning, project management and Owner’s engineer roles for power generation, distribution and utilisation for mining and public utility clients. Danny is currently working in the area of Asset Management with emphasis on the condition and risk assessment of ageing HV/LV electrical equipment. He is an associate and senior electrical engineer at Sinclair Knight Merz and is the SKM Practice Leader for “Electrical Safety and Compliance”. Danny holds a BEng in Electrical Power Engineering from Curtin University and a post-graduate diploma in Safety in Design. He is an accredited internal auditor to ISO9001 and a fellow of the Institution of Engineers, Australia. |
Dale Wright has worked in the field of electrical power engineering for 8 years and is currently engaged as an electrical engineer within SKM’s Power and Energy Division. He has significant experience in engineering works associated with building services, mining and heavy industry sectors in the areas of power transmission and distribution. Dale has undertaken design, project management, feasibility and options studies, protection engineering, regulatory work, strategic consulting, electrical system studies and investigations. He has more recently been involved in electrical safety in design issues, focusing on arc flash risk assessments and mitigation options for ageing HV and LV electrical switchgear and is currently responsible for the upgrade design and documentation of this equipment. Dale holds a BEng in Electrical Engineering from The University of the Witwatersrand, South Africa. He is a member of the Institution of Engineers, Australia. |
References
Stokes, A.D., and Sweeting, D.K., 2006—Electric arcing burn hazards. IEEE Transactions on Industry Applications, 42 (1), January/February 2006.Sweeting, D.K., and Stokes, A.D., 2007—Energy transfers with arcing faults in electrical equipment. International Conference on Fuses and their Applications, Clemont-Ferrand France, 10–12 September.
Commission for Occupational Safety and Health—Guidance Note, General Duty of Care in Western Australian Workplaces, 2005.
SR OHSAS 18001:2007: Occupational health and safety management systems—Requirements.
AS/NZS 4801:2001: Occupational health and management systems—Specification with guidance for use.
