What Causes an Arc Flash and How Do We Protect Employees?

Arc Flash Warning Sign for Workplace Safety

At the  beginning of each year, Data Aire  schedules training or a refresher on several critical safety topics.  The safer our team is, the better we maximize our lean manufacturing processes and maintain on-time delivery. One  course we offer is NFPA 70e Arc Flash training. Many people may be aware of this standard or know of it because they’re in an industry that requires employees that work with higher electrical current loads to have this training. Others may be less familiar with this topic. Let’s break it down and cover the key points you need to know if you or your employees are exposed to electrical current that could result in an arc flash.

What is NFPA?

NFPA is short for National Fire Protection Association which is a trade association that creates and copyrights standards and codes which are then often adopted by government agencies. FYI – The NFPA is best known for its sponsorship of the National Electrical Code which we’ve all heard of!

The specific NFPA standard we’re discussing, 70e, describes safe electrical work place practices for electrical construction, service and maintenance. Keep in mind, this is not intended for the electrical utility companies per se but rather industrial applications and construction operations. It also doesn’t cover other safety topics other than where PPE for electrical work is specified.

And, another consideration: even though NFPA 70e is not necessarily a law — since you won’t find it incorporated into The OSHA CFR (Code of Federal Regulations), OSHA does require that employers must warn employees about any electrical hazards that exist in the workplace. The  NFPA 70E standard outlines a widely-accepted approach to meet OSHA’s requirement for this particular hazard.

What is an Arc Flash and How Can an Arc Flash Happen?

An arc flash is an undesired electric discharge that travels through the air between conductors or from a conductor to a ground. The resulting explosion can cause serious harm to people, fires and damage to equipment. The arc flash occurs during a short circuit. It happens when current flows thru an air gap between conductors. Dust and corrosion or even normal wear and tear can be factors that result in an arc flash.

The temperature of an arc flash may actually exceed 35,0000 F (hotter than the Sun) and is capable of vaporizing metal and sending a blast of plasma (think of it as a gas that can conduct electrical current) and molten metal in all directions with extreme force. Generally, an electrical system must run at 480V or greater to supply an arc flash; the higher the voltage, the higher the risk. Injury and damage are caused both by the explosion of the arc flash and by the heat radiating from the blast.

It is possible to protect against arc flash with the proper protective equipment and, more importantly, safety procedures and training. Your safety consultant / suppliers can help you with selection of proper PPE (personal protective equipment) for your operation.

However, the most important thing you can begin with is education. Short three to four-hour classes are available to quickly bring you up to speed. Once you know what is required, you can plan your approach. Start making plans today and make safety a priority!