Comparison of Low-Voltage Arc-Resistant Equipment, Equipment With Isolation Barriers, and Equipment With Energy-Reducing Line-Side Isolation for Reduction of Arc-Flash Hazards

Arc-resistant equipment, isolation barriers, and energy-reducing line-side isolation (ERLSI) are different solutions for arc-flash hazard reduction that on the surface appear to be similar, but when considered in detail are quite different. Arc-resistant equipment redirects or contains an internal arc fault within the equipment so that under certain conditions personnel are exposed to a lower arc-flash hazard. An isolation barrier installed in equipment can, under the right conditions, substantially lower the likelihood of inadvertent contact across the barrier. ERLSI is an equipment feature that is similar to an isolation barrier, but with enhanced functionality and applied to the line-side of the equipment main overcurrent protective device to reduce arc-flash hazards. All three solutions, when properly applied, reduce the arc-flash risk to the electrical worker but under different conditions. This paper compares the application of these three solutions based upon considerations of selection, limitations, benefits, conditions under which arc-flash hazards are reduced, maintenance, and end of life.