The SEL-487E limits transformer damage by responding to internal fault conditions in less than 1.5 cycles. The relay also helps avoid catastrophic transformer failure by detecting turn-to-turn faults involving as little as 2 percent of the total winding. You can minimize commissioning time and eliminate costly errors with included software that recommends matrix compensation settings. Through-fault and thermal monitoring allow you to track transformer wear and schedule maintenance as necessary. Breaker wear monitoring reduces inefficient and costly breaker maintenance, saving time and money. The SEL-487E includes two differential elements as well as comprehensive feeder and distance protection, making it well suited for protecting a distribution substation or switchgear using a single device. Apply the SEL-487E-4, with its 6 voltage and 18 current terminals, as a station phasor measurement unit.