One of the most effective ways of managing electrical arc flash events is by implementing the appropriate controls and utilising the correct PPE.
Arc flash PPE should be chosen based on either:
- an incident energy analysis method or
- a hazard/risk category method.
It is surprising the amount of electrical flash-overs or arc flash accidents that occur every year causing worker injury and fatalities.
Perhaps what is most concerning about arc flashes is that it doesn’t only affect workers in close proximity but when caused by inadvertent contact between an energised conductor with another conductor or an earthed surface, an arc flash can melt conductors, ionise the air and develop into a conducting flash arc within which temperatures have been known to reach 20,000°C, so even workers not working in close proximity to electrical conductors may be at risk.
Injuries caused by arc flashes can burn the skin quite badly and can also result in internal burns from inhaling hot gasses and vaporised metal. Worker’s eyesight and hearing may also be negatively affected. Fatalities have been known to occur during these events.
In some extreme cases arc flashes can involve explosive force known as an arc blast which can launch shrapnel at high speeds of up to 300 metres per second, leading to even more injury.
Usually workers who are exposed to arc flashes and arc blasts usual suffer serious injury which require extensive treatment to correct, that means time off work, loss of income and loss of productivity.
According to the UK standard dealing with an Arc Flash hazard needn’t be complicated, it can be handled in a matter of a few steps:
- Prediction: Predict the likelihood of an arc flash occurring and the severity and scope of the impact. The prediction is made by assessing the amount of ‘incident energy’ received during an event by a person within the reach of the arc.
- Prevention: Attempt to prevent arc flashes from occurring. Ensure that the risk from arc flash is addressed at this level through either designing out, elimination entirely or by remove the hazard at its source.
- Personal Protective Equipment: This should always be the last line defence in dealing with arc flash events. Risk assessments for those working on or in close proximity to energised electrical equipment will likely indicate a requirement for full-body electrical PPE, in other words an arc flash hood and gauntlets.
- Communication and Training: The communication and documentation of both the assessment and strategies or steps that are in place to ensure safety must be provided to those at risk from an arc flash event. Workers must be trained on the hazards that they face, that includes electrical risks. Also employers must continuously assess whether controls that are in place are still effective or whether they need to be adjusted in order to remain effective in controlling the hazard.