In electrical jargon, an arc refers to a luminous bridge that manifests between 2 live electrodes. An arc flash occurs if that circuit undergoes a fault or short circuits through this gap.
The flash can result from accidental contact, corroded or damaged circuitry, contamination of an insulated surface among others. Whatever the cause may be, it always generates a huge flash or large amounts of energy which can be deadly. The arc causes the air to ionize and temperatures can reach as high as 5,000°F depending on the severity of the flash.
Types of Injuries resulting from an arc flash
This kind of heat can set clothing on fire and burn human skin in seconds even if a worker is standing a couple of feet away from it. The heat is also hot enough to ignite combustible items that are near the arc site and melt metal such as copper and aluminum conductors. The material reacts violently since it changes from solid to vapor form directly under immense heat resulting in an explosion.
The pressure from the energy generated can knock workers off their feet, adders, scaffolds and even throw them against walls or heavy equipment. The sound blast can rupture eardrums resulting in either permanent or temporary hear loss depending on the proximity of the worker.
In addition, molten metal from the blast can be sprayed across the worksite and land on workers meters away leading to serious burns. Besides this, solid metal objects or equipment can turn into projectiles while the blinding flash from the explosion can impair vision or cause permanent eyesight loss.
All of these injuries result in equipment damage, debilitating injuries and even death.
How much energy is generated during an arc flash?
An arch flash that is caused by a phase to phase fault that does not have arc protection in place, can generate an explosion that is equal to what one stick of dynamite offers. However, the chances of that happening can be reduced if time is reduced via current-limiting fuses or high resistant grounding in the case of phase to ground faults.
Electric arc flashes are uncontrollable flashes of luminous discharge and energy that flows along insulating mediums. The most common cause is insulation failure due to aging insulation material, poor maintenance, vermin issues and human error. A tool that touches live conductors accidentally for instance can generate enough energy to create an arch flash.
Arc flash events
are dangerous can be deadly to personnel if they are not protected. According to the Occupational Safety and Health Administration, these events make up 80% of electricity related accidents in the workplace even among experienced workers. It can also destroy millions of dollars worth of equipment or damage it leading to thousands of dollars in downtime and repair work.
According to the National Electrical Code, all onsite electrical equipment should be marked to warn personnel of potential dangers that can result from arc flash incidents. In order to ensure this safety measure, the hazard from the event should be quantified by measuring its incident energy. This is the energy that is present on the surface at a specific distance from the event.
NFPA 70E – Standard for Electrical Safety in the Workplace
Electricity is a useful but also an extremely powerful tool that needs to be handled with care. Workers usually work in close proximity to high voltage equipment or wires that can cause an arc flash with the smallest of errors. Ensure your employees remain free of injuries by signing up for 360Training.com’s NFPA 70E standard for electrical safety course
360Training.com also has a comprehensive library that is filled with a range of safety training courses that workers can benefit from. All of the courses are held online for the convenience of students and all of them fulfill compliance needs via a flexible work schedule.
Train your supervisors how they are responsible for the safety of worksite personnel by signing them up for the library today. Besides electrical training, some of the material on offer includes lockout/tagout, ergonomics, asbestos hazards in the workplace, welding, brazing, cutting, safety and health programs, personal protective equipment among others.
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