EVs and the DC Hazard: EBT AR Garment Exposed Above Arc Rating

With the rapid growth of electric vehicles (EVs), and the infrastructure needed to support them, so too grows the importance of understanding the direct current (DC) arc hazard. That’s where Tyndale comes in! This series lays out the differences between the alternating current (AC) arc hazard and its lesser-known DC counterpart and demonstrates – through first-of-its-kind real-world video footage – the power of DC arcs. Follow along to learn more and witness firsthand the life-saving difference the right arc-rated (AR) clothing makes in the face of a DC arc.

In our previous episode, we showed you how Tyndale’s FRMC® arc-rated (AR) shirt and jeans perform in a DC arc flash.

Explore the Boundaries of DC Arcs

Hold on tight as we push the limits! We're intentionally subjecting an energy breakopen threshold (EBT) AR garment, rated at 9.1 calories, to four calories above its threshold. EBT garments are specifically designed to indicate the level of energy required to cause the fabric to break open and expose the wearer to potential burn injuries during an arc flash event. Our audacious experiment aims to reveal the striking differences between break open in DC and AC arcs. Prepare for surprising revelations as we delve into the power of the continuous current of DC arcs.

While the garment may appear intact from one angle, a closer examination through our GoPro footage reveals subtle break open occurrences. Notice slight break open above the right-hand pocket and a smaller area on the left-hand side, commonly observed due to the weight exerted by the pocket and flap. As expected, once the fabric carbonized, its mechanical strength weakens, leading to break open in those areas

Even though the garment experienced slight break open, and even though we tested four calories over the arc rating of the shirt, we expect no body burn through the garment because this wearer was also wearing an AR base layer – stressing the importance of proper AR layering in face of potential electrical hazards.

Why are we Testing Garments Above Their Arc Rating?

There can be real-life situations where individuals are inadvertently exposed to arc ratings greater than what their protective apparel is rated to take due to various factors:

  • Miscommunication or oversight
  • Task changes or unexpected hazards
  • Unforeseen incidents or accidents

This video shows why it’s so important to wear AR clothing (including AR base layers) and appropriate PPE when there is an arc hazard in your job environment. In fact, in most of the injuries and fatalities we see, the outcomes were preventable – caused by people wearing fuel. This video shows that the DC arc hazard is no exception. Don’t leave home without your last line of defense.

Next up, we test how an UltraSoft ® Coverall performs in the face of a 9 calorie DC arc.


Series: EVs and the DC Hazard

Think you know arc flash? Think again. DC arcs are different. Following along with this series to see how different – and how to stay safe.

Leave a Reply

Your email address will not be published. Required fields are marked *