Protect and monitor most transformer applications with the powerful SEL-487E Transformer Protection Relay. Apply up to 5 three-phase restraint inputs, three independent restricted earth fault (REF) protection elements, and 2 three-phase voltage inputs, all with synchrophasors. Limit transformer damage by responding to internal fault conditions in less than 1.5 cycles. Avoid catastrophic transformer failure by detecting turn-to-turn faults involving as little as 2 percent of the total winding. Minimize commissioning time and eliminate costly errors with 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. Optional Time-Domain Link (TiDL) technology transforms the way you modernize your substation.