Current Differential Protection for Up to Six Terminals
Achieve fast, sensitive, dependable, and secure differential protection. A two-stage slope adapts to internal or external fault conditions automatically, even with CT saturation and heavily distorted waveforms.

Security and Dependability
Provide maximum security during external faults and transformer magnetizing inrush conditions. You can detect internal faults quickly, during energization or normal operating conditions, using combined harmonic-blocking and -restraint differential elements. The SEL-487E detects turn-to-turn winding faults for as little as 2 percent of the total transformer winding with the negative-sequence differential element.

Additional Protection
Apply two three-phase voltage inputs for over- and undervoltage, frequency, synchronism check, and volts-per-hertz protection. You can make any overcurrent element directional using voltage-polarized directional elements as torque control inputs to the overcurrent elements. Adaptive time-overcurrent (IDMT) elements allow you to implement transformer and feeder protection. Three independent REF elements enable sensitive ground fault detection in grounded wye transformer applications. Assign the distance element to any terminal on the SEL-487E to provide up to four reversible zones of distance protection. The distance elements can be used for traditional line protection or as part of a transformer protection scheme. Apply the second differential element for bus bar protection. The SEL-487E includes comprehensive feeder protection, including reclosing, and a single device can protect up to six feeders.

Centralized Protection and Control
The SEL-487E delivers a CPC solution that offers complete protection for small substations and is highly adaptable, maximizing the benefits of any given application. Connect to conventional instrument transformers using traditional copper connections or as part of a digital secondary system (DSS) solution, such as IEC 61850-9-2 SV or  SEL TiDL technology. In these DSS applications, merging units acquire data close to the instrument transformers and send the data to remote SEL-487E relays to provide the required information.

Synchrophasors
Send IEEE C37.118 synchrophasor messages over serial or Ethernet communications to detect reactive loop flows, turn state estimation into state measurement, and provide early warning of potential system instability. Apply control functions based on phase angles, currents, and voltages for basic or advanced applications. Multicast synchrophasor data to simplify system architecture and improve system operations. For applications requiring a dedicated PMU, choose the SEL-487E-4 Station Phasor Measurement Unit.

Monitoring and Asset Management
Monitor and protect critical substation assets with the IEEE C57.91 and IEC 60255-149 thermal models for mineral oil-immersed transformers. You can use the IEC thermal element to trip a breaker or use either the IEC or the IEEE thermal elements to activate a control action or issue an alarm when the transformer is in danger of excessive insulation aging or loss of life. Advanced monitoring features include transformer through fault, substation battery voltage, and comprehensive breaker wear monitoring.

Metering and Reporting
Eliminate external recorder and metering requirements with oscillographic event reports, Sequential Events Recorder (SER) reporting, and three-phase power metering. These tools simplify post-fault analysis and improve your understanding of protective scheme operations.

Front-Panel One-Line Diagrams Control and Monitoring
Select your own system bay configuration, and control as many as 6 breakers and 20 disconnect switches using the built-in mimic diagrams that include programmable analog quantities for readouts.

Automation and Control
Implement SELogic control equations with SELogic variables, timers, latch bits, and remote control elements for customizing advanced protection and control schemes. Control logic can replace panel control switches, RTU-to-relay wiring, latching relays, and traditional indicating panel lights.

SEL TiDL-Based Solutions
Apply a TiDL-based process bus solution, where SEL-TMU devices are placed in the yard close to the primary equipment to digitize discrete I/O signals and analog data. SEL-TMU units exchange these data with an SEL-487E-5 TiDL relay in the control house. Each SEL-TMU can share data with as many as four TiDL relays, providing protection design flexibility.

TiDL combines the proven protection of the SEL-400 series relays with the purpose-built SEL-TMU, simplifying deployment, reducing training requirements, and increasing availability. TiDL technology uses point-to-point connections and a non-Ethernet protocol, providing a simple and secure solution. TiDL also provides built-in data synchronization and synchronous sampling, ensuring protection is available in the relay regardless of whether an external time signal is available.

SEL SV-Based Solutions
Based on the IEC 61850 standard, SV-based solutions maximize flexibility and interoperability. The SEL-401 Protection, Automation, and Control Merging Unit and the SEL-421-7 Protection, Automation, and Control System Merging Unit digitize analog signals from primary equipment and send them using the SV protocol to an SEL-487E-5 SV relay in the control house. Because all SEL SV devices are compliant with IEC 61850-9-2 and the UCA 61850-9-2LE guideline, the SEL-487E-5 SV relay can be used with other manufacturers’ IEC 61850-compliant units.

Flexible Ethernet Communications
The two-, four-, and five-port Ethernet communications card options enable you to communicate using a variety of protocols, including FTP, HTTP, DNP3, PTPv2, PRP, Telnet, synchrophasors, and IEC 61850 Edition 2.

The TiDL and SV relays can be configured with a five-port Ethernet card supporting PRP or failover functionality to increase system availability, as well as the Precision Time Protocol Version 2 (PTPv2) on process bus or station bus ports for time synchronization. Use network monitoring features in the relay to further improve system availability by actively monitoring each redundant path to detect communications network failures. 

The five-port card also features dedicated ports and IP addresses for station bus and engineering access networks to provide selective access control. All ports support SFP transceivers. Single- and multimode communications options provide increased flexibility. All ports support 100 Mbps SFP transceivers, and process bus ports also support 1 Gbps SFP transceivers.

Serial Communications
All four independent EIA-232 serial ports support SEL Fast Message, SEL ASCII, Compressed ASCII, SEL Fast Operate, SEL Fast Meter, SEL Fast SER, enhanced SEL Mirrored Bits communications, and DNP3 Level 2 Outstation as well as dial-out, Virtual Terminal, and communications with SEL-2600 series RTD modules.

Simplified Settings Management
Use acSELerator QuickSet SEL-5030 Software to develop relay settings offline and program SELogic control equations. Configure the TiDL and SV relays using SEL Grid Configurator, a software tool that increases efficiency and improves settings insights. It features a spreadsheet-style editor, protection visualization, comprehensive reporting, custom filters, and multiple-device settings management.