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.

Applications

Multiwinding Protection—Configure the SEL-487E for transformer differential protection in transformer applications using up to five restraint currents. This includes single transformers with tertiary windings. Use three independent REF elements for protection of grounded-wye windings.

Sensitive Turn-to-Turn Fault Detection—Avoid catastrophic transformer failure. Detect turn-to-turn faults involving as little as two percent of the total winding with the patented negative-sequence differential element.

High-Speed, Adaptive Differential Protection—Implement a two-stage slope that automatically adapts to internal or external fault conditions, even with CT saturation and heavily distorted waveforms, for fast, sensitive, dependable, and secure differential protection. The adaptive differential element responds to internal fault conditions in less than 1.5 cycles.

Diverse Transformer Applications—Protect large transformers with breaker-and-a-half high- and low-side connections. Also, configure for a typical two-winding transformer application, and use the remaining three-phase current inputs for feeder backup protection.

Generator Step-Up Protection—Protect generator step-up (GSU) transformers, and apply the built-in thermal elements (requires the SEL-2600 RTD Module) for monitoring generator and transformer winding temperatures simultaneously.

Advanced Asset Monitoring—Track transformer wear with through-fault and thermal monitoring. Reduce inefficient and costly breaker maintenance with advanced breaker monitoring. Monitor substation dc power systems for out-of-tolerance voltage levels or excessive voltage ripple.

Station Phasor Measurement Unit (PMU)—Improve power system quality with SEL synchrophasors (IEEE C37.118) from all 24 analog channels (6 voltage and 18 current sources) in your relay. Use synchrophasors over serial or Ethernet communications to easily detect reactive loop flows, turn state estimation into state measurement, and provide early warning of potential system instability. Implement real-time control by receiving synchrophasor messages from two PMUs, and take action based on local and remote messages.

Dependable Backup Protection—Provide backup protection with five phase, negative-sequence, and zero-sequence overcurrent elements and ten configurable time-overcurrent elements. Quickly identify the faulted phase with faulted-phase indications for each overcurrent element. Set up breaker failure protection with subsidence detection to rapidly detect breaker failure and minimize system coordination times.

TiDL Technology—Modernize your substation by applying the TiDL-enabled SEL-487E with the SEL-2240 Axion TiDL nodes. In a TiDL system, the Axion node provides remote I/O and digitizes analog signals over fiber optics for the relay. This simple and secure digital secondary system solution is easy to implement, with no external time source or network engineering required. Replacing copper with fiber increases safety, reduces costs associated with using copper, improves reliability, and limits the impact of an electromagnetic pulse.