“When I looked back and saw that I had no pants on the back of my legs, and literally, the skin was hanging off my arms and my legs, I just knew something horrific had happened.” So begins the story of one worker injured by an arc flash, as recounted by NIOSH’s three-part Arc Flash Awareness video series to demonstrate the serious, life-or-death nature of arc flash injuries.
Arc flash explosions, which occur when an electric current jumps through an air gap between conductors, may exceed temperatures of 35,000 degrees Fahrenheit. The heat and energy emitted can result in serious injury, fire, equipment damage and death. According to the Bureau of Labor Statistics, nonfatal electrical injury most often occurs from contact with the electric circuitry of machines, tools, appliances or light fixtures. Another leading cause includes contact with energized equipment including transformers, motors and switchgear of various voltage ratings.
To provide safety professionals with the best information about preventing and protecting workers from arc flash, EHS Today has compiled the following articles and resources surrounding arc flash:
EHS Today’s sister publication, Electrical Construction and Maintenance (EC&M), recently published an article covering the five common pitfalls in arc flash hazard evaluation that can cause flawed results. “Arc Flash Hazard Evaluation” discusses source impedance; transformer grounding; determining whether to use the IEEE 1584 or NESC Art. 410 standard; bolted fault current vs. arcing fault current; and circuit impedance.
For a look at the personal protective equipment (PPE) needed to protect workers from arc flash injuries, read “Taking Steps to Protect Workers from Common Arc Flash Hazards.”
“Assess the electric arc hazards in your workplace and refer to NFPA standards to determine the corresponding PPE required for each task,” the article suggests. “When selecting eye and face protection, choose products with the required arc rating specific to the hazards present. Be sure that eye and face protection also provides exceptional visual acuity so workers can see fine details and perform work safely, a property assured with the use of Z87.1 compliant products.”
Arc Flash Calculation Secrets Revealed
EC&M’s article “The Secret to Understanding Arc Flash Calculations” acknowledges that arc flash calculations remain a challenge for many. Even so, understanding and following arc flash regulations provides multiple benefits:
“Arc flash regulations may be one of the best things that have ever happened to electrical designs, because they force engineers to look closer at details they might have otherwise overlooked in the past and put the power system calculations front and center in the design process,” the article states. “The very notion of considering arc flash early on in the design of a power distribution system is not only prudent, but also economical.”
“The Secret to Understanding Arc Flash Calculations” discusses safety-related work practices; limits of approach; incident energy and arc flash boundary calculation methods; guidance on selection of protective clothing and other PPE; and more.
Finally, EC&M’s “The Case of the Exploding Chain Saw,” by Leonard Greene, P.E., offers a retelling of one electrician’s harrowing on-the-job incident. This article reveals the potentially devastating effects of arc flash injuries:
“When I met the victim two years after the accident, he was still unable to walk without a brace, had no short-term memory, and was in rehab for stroke symptoms on his left side. His marriage had ended, and his future indicated lifetime support needs ... the workman’s comp claim was insufficient to cover the victim’s extensive rehabilitation costs and loss of income ...”
To learn more about how arc flash can impact lives, take it from this worker, who shared his story in the NIOSH video series: “I would say the biggest way it has changed me is in my attitude,” he explained. “It’s trying to expect the unexpected. It’s being ready for anything, because anything may happen.”
To learn more, watch Part 1 of NIOSH’s Arc Flash Awareness video below: