phase protection relay / three-phase / panel-mount / programmable
SEL-487E Schweitzer Engineering Laboratories



  • Measured/monitored value:


  • Other characteristics:

    three-phase, panel-mount, programmable, digital, differential


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 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 allows you to track transformer wear and schedule maintenance as necessary. Breaker wear monitoring reduces inefficient and costly breaker maintenance, saving time and money.

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