Arc Flash dangers hiding in plain sight

Every year in Australia, there are dozens of preventable workplace incidents involving an arc flash (also known as an arc fault) – ones that result in serious injury or death. 

While there is no single nationwide tally available, an analysis of admissions to major NSW burns units for 2003-2006 concluded that 129 were likely due to arc flashes.

In 2018, a spate of serious arc flash incidents in Western Australia’s mines brought the issue to the fore again, highlighting that they are not confined to one particular industry. Likewise, they are not only associated with high voltage equipment. 

Low voltage arc flashes, while less common, generally have a higher release of energy at the incident point. Consequently, the ensuing damage to equipment is greater, as is the increased risk of permanent injury to or death of the worker. 

Similarly, arc flashes in enclosed spaces will be focussed and deliver a higher rise in pressure. Because this buildup is directed toward any opening, a person working at the open door of a switchboard is at risk. 

As contact is not necessary, any workers near the live conductors or equipment are at risk of exposure to arc flash. And all it takes for an arc flash to happen is for a low impedance electrical connection to be made across phases, or from phase to neutral, or from phase to earth. Even a buildup of dust or carbon on the terminals could set one off.