As Tyndale extends our managed arc-rated and flame resistant (AR / FR) clothing programs into Canada, we invite you to follow along in our Proud to Protect Canada series. While many of the topics in this series contain Canadian-specific content, there are some topics that are relevant on both sides of the border – like this one. We hope you enjoy “meeting” our Canada Team, exploring engaging and relevant content, while learning about our unique solution and the benefits it provides to companies and wearers alike.
In the first episode of our Proud to Protect Canada Series, we talked about why it’s so important to wear arc-rated flame resistant (AR / FR) clothing to protect against life-threatening burns due to thermal hazards. In this episode, we’ll learn more about an extremely dangerous type of thermal hazard: arc flash. Anyone working on or near energized electrical equipment must be alert to the danger of arc flash and take every precaution to protect themselves from severe injury or death.
So, what exactly is an arc flash? Tyndale’s Canada Sales Director, Paul Castelli, and VP of Technical, Scott Margolin, explain how arc flash occurs by sharing dramatic video footage of this very “explosive” subject:
What is an arc flash?
An arc flash is a sudden release of energy that results when a fault or short circuit condition causes electrical energy to leave its intended path and travel through the air, “jumping” from one conductor to another. As Scott explains, an arc flash occurs when the electricity that is supposed to be inside the wires gets outside of the wires. It then takes a path through the air to the ground, creating ionized gases. The result? The energy flow generates enormous light and heat and creates a shockwave that radiates outwards. Arc flashes melt metal, and the shockwave causes the molten metal to travel long distances at extremely high speeds, creating an additional hazard to anyone in the vicinity of the blast.
What causes an arc flash?
Some common causes of arc flashes are dropped or carelessly placed tools, a worker accidentally touching a live exposed part, dust, condensation, misalignment of contacts, or corrosion. They can occur in both high- and low-voltage environments. Lower voltages don’t necessarily mean less risk; 480V arcs are among the most common. Typically, arc flashes only last a fraction of a second. But they can generate temperatures of up to 35,000°F – approximately four times hotter than the sun’s surface – presenting a tremendous hazard.
What are the dangers associated with an arc flash?
Second-degree burns to the skin begin at 140°F. Flammable clothing, such as cotton, typically ignites at approximately 450°F. The extreme heat generated by an arc flash, and the molten metal, which is at least 1,900°F, are enormous hazards to nearby workers with exposed skin or wearing flammable clothing. This heat can ignite non-protective clothing quickly, leading to severe or fatal burns. The risk is amplified in the case of clothing made with synthetic fibers that melt and adhere to the skin, resulting in even greater injury or even death.
How do you protect against the dangers of an arc flash?
Always follow proper safety protocols and procedures, and whenever possible, de-energize the equipment before working on or near it. However, powering down equipment can create a more dangerous condition in certain circumstances. When energized work is unavoidable, workers must wear the appropriate arc-rated clothing and other required PPE. In addition, adhere to regular maintenance schedules in any environment where electricity is present.
Compliance with OSHA regulations and relevant safety standards (more on those in Episode 3!) is critical to preventing arc flash incidents and injuries. But no matter how many safety measures and precautions are taken, you should always wear AR / FR clothing as a last line of defense. Arc-rated clothing will not support combustion and will insulate the wearer from the intense heat of an arc flash up to the arc rating (the amount of energy the fabric can block before the wearer receives a second-degree burn). You must ensure you’re wearing clothing with an arc rating equal to or higher than the possible incident energy.
Stay tuned for the next episode in this series which explains the Canadian standard that governs arc flash, CSA Z.462, and its US counterpart, NFPA 70E. Visit our series hub to read episode summaries and catch up on all topics in the series.
Series: Proud to Protect Canada
Follow along with this series to explore our educational resources for companies and workers based in Canada. You’ll meet the technical and market experts from our Canada team and find everything from the basics on the hazards, to PPE and labeling requirements, a closer look at key safety standards and the hierarchy of standards and regulations in Canada, employer responsibilities under the Canadian Labour Code, and more.