With 80% of electrically related accidents and fatalities among qualified electrical workers being caused by industrial arc-flash events, 67% industrial professionals surveyed reported completing an arc-flash hazard assessment. More than 50% of survey respondents reported having significant arc-flash hazards and agreed that reducing those hazards is important.
The most popular mitigation technique is current-limiting fuses, followed by arc-resistant switchgear, arc-flash relays and high-resistance grounding. Although arc-resistant switchgear is popular, 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, however, phase-to-phase arc faults or phase-to-phase-through-ground arc faults can still occur in high-resistance grounded systems. Arc-flash draws less current than a bolted fault and may not be interrupted by the circuit-breaker in its instantaneous operating time, therefore, it should be used over current-limiting fuses.
“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., 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 centres,” Glenney added. “The fast adoption of arc-flash relays and other mitigating techniques will have a significant impact in improving plant worker electrical safety.”