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An Electrical Arc is the passage of current through an air gap as it's dielectric properties can no longer withstand the voltage buildup across it. The Arc Flash is the immediate, unintended release of great amounts of energy caused by an Electric Arc within an electrical equipment. This tremendous amount of energy is released in the form of heat, light, sound and blast waves. An Arc Flash can generate temperatures as high as 19,000 °C, such that the blast products often consists of vaporized copper, steel or aluminium.
The following are some factors that may result in an Arc Flash:
- Human errors such as tools dropping into energized switchboard during maintenance
- Aging or insulation defects of electrical components
- Ingress of dust/vermin into electrical equipment compromising the distance between energized parts
- Personnel not adhering to safety procedures during maintenance or operations
- Overheating of contacts due to loose connections or corrosion
- Electrical components subjected to harsh, highly humid or corrosive environments
- Inadequate protection by relay systems
- Ferroresonance generated in instrument transformers
- Closing of breakers to an existing fault
- Inadequate insulation at cable terminations
An Arc Flash incident can cause significant damage to electrical equipment, indirectly causing extensive
disruptions to the operations of a facility. An Arc Flash incident very often also results in fatalities or serious injuries of work personnel.
It is the responsibility of the employer to assess the Arc Flash risks at the workplace and to ensure that the workers are appropriately protected. An Arc Flash Analysis should be performed to determine the potential exposure of any workers to an Arc Flash before they are allowed to work on any energized equipment. The analysis defines the arc flash boundary distance and the category of Personal Protection Equipment (PPE) required.
We are able to assist you in conducting an Arc Flash Analysis of your facility in accordance to the following standards:
- NFPA 70E (2012)
- IEEE Std 1584.1 (2013)
We are also able to assist you in the prevention of Arc Flash hazards by the upfront design or the lifecycle assessment of your electrical infrastructure.
If you are keen to assess the Arc Flash risks of the facilities under your charge, please do contact us.