Electrical flashover or arc flash is one of the most deadly and least understood hazards of electricity and is prevalent in most industries. Each year around 1,000 electrical accidents at work are reported and as many as 25 people die from their injuries. It is widely recognised the higher the voltage of an electrical power system, the greater the risk for people working on or near energised conductors and equipment. However, arc flash can actually be worse and more common at lower voltages and can cause devastating, severe burn injury and even death
What is an electric arc flash?
An arc flash is usually caused by inadvertent contact between an energised conductor such as a bus bar or wire with another conductor or an earthed surface. When this occurs, the resulting short circuit current will melt the conductors, ionise the air and create a conducting plasma fireball with temperatures in the core of the arc that can reach upwards of 20,000 degrees centigrade. Severe injury and even death can not only occur to persons working on the electrical equipment but also to people located nearby. Arc flash injury can include external burns to the skin, internal burns from inhaling hot gases and vaporised metal, hearing damage, and eye damage such as blindness from the ultraviolet light of the flash.
Managing the hazard
The arc flash hazard needs to be determined by risk assessment that will identify whether to work on equipment that is live or dead and therefore the precautions that will be required. To help companies better assess the arc flash hazards the DuPont™ Arc-Guide has been developed in conjunction with independent experts to provide them with the knowledge on how to both reduce the severity and consequences of an arc flash. The arc flash hazard is a serious electrical risk that needs to be managed in many industrial environments and risk assessment for workers who operate in proximity to, or on, energised electrical equipment and cables is essential to ensure safety and compliance with the law. It is advisable to adopt the step by step approach of predict, prevent, protect and publish recommended in the DuPont™ Arc-Guide :
Predict – the severity of the thermal effect of an arc flash by the amount of ‘incident energy’ that a victim, standing at a given distance away from the arc, could receive.
Prevent – design out, eliminate or remove the hazard at its source.
Protect – where the risk cannot be controlled by prevention or where there is a residual risk of injury then it may be necessary to consider personal protective equipment (PPE) to prevent injury to the worker.
Publish – communicate and document results of site arc flash to those who are at risk.
For further information about the DuPont™ Arc-Guide, visit www.arcguide.dupont.com.
Those wishing to register for the European Electric Arc Risk Assessment Forum must register before the 15 November 2011 at www.arcseminars.dupont.com.
Electric Arc Forum
To help companies better assess these risks, DuPont holds thought-provoking workshops that examine the European approach to electric arc hazards and provide an understanding of the legal standards and frameworks. DuPont is holding its third European Electric Arc Risk Assessment Forum on Thursday 17 November 2011 in Manchester, UK, where attendees will also be able to view and experience the DuPont™ Arc-Guide.
The event is free to attend and aimed at anyone whose responsibility involves the protection of workers from the arc flash hazard — for example electrical engineers, electrical designers, contractors and non site based electrical workers and safety managers or procurement officers. Those wishing to register for the European Electric Arc Risk Assessment Forum must register before the 15th November 2011 www.arcseminars.dupont.com
