KEY ISSUE
ARC FLASH HAZARD AND ELECTRICAL CONTRACTING: PART 1 — THE HAZARD AND UK LEGISLATION This article is the first of two parts written by Mike Frain CEng FIET MCMI on the arc flash* hazard and UK legislation. It discusses the dangers posed to individuals during everyday tasks and the risks faced by contracting companies that fail to manage this hazard properly.
I
n 1989, as an electrical contracting engineer, I was called by the Health and Safety Executive to testify in court against a contracting electrician under the Health and Safety at Work Act 1974. The electrician’s apprentice had been injured in an arc flash, and I was first on the scene to secure the area. I knew of other arc flash incidents, including two fatal ones at the same company in the late 80s involving 11kV oil-filled switchgear during post-maintenance service. In the same year that I was to testify in court, the Electricity at Work Regulations 1989 were published. A year later, I helped write and publish new low voltage codes of practice for my company and trained 400 contracting electricians. Since then, I have dedicated my efforts to the safety of electrical workers by participating in international standards committees. I have also provided
consultation to numerous leading companies across Europe and other regions, and have authored many articles on the subject, including the European Arc Flash Guidebook.
Another case was at a mining company where two contracting electricians suffered severe burns in separate incidents. One electrician received serious burns from an 11kV electrical system after placing a vacuum cleaner nozzle into a live electrical chamber. Another electrical contractor received serious burns during electrical testing works on a 400V electrical system at the same site. The fine was £3.6 million with £185,000 costs after an investigation by the Health and Safety Executive (HSE).
Does arc flash affect electrical contractors?
Arc flash (electrical flashover) is a hazard that impacts electrical contractors, and, in the UK, arc flash injuries are most common among electrically qualified workers. Individuals working with or near electricity may not fully understand the potential for serious injury or equipment damage resulting from arcing faults. Recently, an electrical contractor was fined £1,000,000 plus costs for breaches of section 2(1) of the Health and Safety at Work Act 1974. This was following burns to an electrician who was undertaking routine testing on low voltage circuits.
Consequences of arc flash accidents
Although most deaths due to electricity are caused by shock, numerous injuries result from electrical burns, and arc flash incidents can also be deadly. My book, the European Arc Flash Guide, discusses incidents that have resulted in fatalities, injuries and those where no injuries occurred. Arcing incidents often cause significant losses, regardless of whether individuals have been injured. What other ‘significant losses’ are we discussing? Apart from personal injuries, arc flash can lead to fines and compensation claims for companies and individuals. A damaged brand name may also result, such as when an electrical contractor faces prosecution or receives HSE notices for core competence issues. This could lead to difficult questions from clients during tendering for work and usually needs to be disclosed in pre-qualification questionnaires for contracts. The reason for working live on equipment is often cited as avoiding production interruption. If the affected equipment is so severely damaged that it is put out of action for prolonged periods, then this will usually counter this reasoning.
What are the causes of arc flash? Figure 1.1 Before and aftermath of an arc damaged distribution board
20 | June 2025
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The causes of arc flash can be broken down into three broad categories as shown in Figure 1.2. Human interaction tends to be the most common cause of a flashover. Unnecessary live working, ignoring safety rules and a lack of competence hugely increase the risk.
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28/05/2025 09:31