A recent survey conducted by Littelfuse reveals that arc-flash safety is a priority among plant professionals and that protection technologies such as arc-flash relays are rapidly growing in popularity.
Even 10 years ago, arc-flash danger wasn’t at the top of many minds, but today 85% of the 825 survey respondents agree or strongly agree that arc-flash mitigation is important. According to OSHA, industrial arc-flash events cause 80% of electrically related accidents and fatalities among qualified electrical workers.
Not only has awareness increased; plant managers and company leaders are taking action. The majority of industrial professionals surveyed (67%) reported completing an arc-flash hazard assessment in their facilities.
Arc-flash hazard assessments have been used to determine the Hazard Risk Category (HRC) of each piece of electrical equipment (a scale of 1-4). Although the NFPA 70E is moving away from HRCs, they remain a well-known classification. More than 50% of survey respondents reported having significant (HRC 3 or higher) arc-flash hazards and agreed that reducing those hazards is important.
How then to reduce arc-flash hazards and keep workers safe? Survey respondents ranked the popularity of solutions, with arc-flash relays standing out as relative newcomers that are being rapidly embraced.
The most popular mitigation technique is current-limiting fuses, followed by arc-resistant switchgear, arc-flash relays, and high-resistance grounding. Current-limiting fuses are well established in the industry, however, since an arc-flash draws less current than a bolted fault and may not be interrupted by the circuit-breaker in its instantaneous operating time, other forms of arc-flash mitigation must be used. Arc-resistant switchgear is another option but it can be a costly solution that can be difficult to implement in existing facilities and offers little additional protection when a door is open. High-resistance grounding systems lower the energy available to ground faults and therefore eliminate the occurrence of phase-to-ground arc faults. Phase-to-phase arc faults or phase-to-phase-through-ground arc faults can still occur in high-resistance grounded systems requiring additional mitigation techniques to lower incident energy. Arc-flash relays stand out as relative newcomers that are being rapidly embraced. Arc-flash relays are a growing solution because they rapidly detect the light from an arc and send a trip signal to the circuit breaker to disconnect the power quickly enough to drastically reduce incident energy.
“In an industry that changes slowly, I’ve never seen such a fast adoption of a new technology as I have seen with arc-flash relays,” said Jeff Glenney, P.Eng., of Littelfuse. “Companies feel pressure to reduce arc-flash hazards. Arc-flash relays are easy to install, comparably low cost, and offer simple yet reliable operation.”
“Accordingly, many plant managers are adding arc-flash relays to their electrical switchgear and motor control centers,” Glenney said. The use of these and other devices on circuit-breakers rated 1200 amps or more is now included in the 2014 edition of the NEC, section 240.87 (B).
Considering that many survey respondents have electrical panels rated HRC 3 or higher, the danger of an arc-flash is real. “The fast adoption of arc-flash relays and other mitigating techniques will have a significant impact in improving plant worker electrical safety,” Glenney said.
To read a white paper based on the survey, click here.
For more information on the Littelfuse PGR-8800 Arc-Flash Relay, visit http://www.Littelfuse.com/ArcFlash.
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