Project Description

SEL-587 Current Differential Relay

SEL-587 Current Differential Relay

The SEL-587 Current Differential / Overcurrent Relay provides protection for any two-input apparatus such as transformers, motors, generators, and reactors. Apply it for differential and overcurrent protection and use event reports for quick post-event analysis.

Functional Overview

50 (P,G,Q) Overcurrent (Phase, Ground, Neg. Seq.)
51 (P,G,Q) Time-Overcurrent (Phase, Ground, Neg. Seq.)
87 Three-Phase Current Differential
DFR Event Reports
LGC SELogic Control Equations


Front- and Rear-Panel Diagrams

SEL-587 Front Panel SEL-587 Rear Panel
Front Rear



Use single- or dual-slope percentage-restraint differential characteristics and overcurrent elements. Backup overcurrent protection provides high-speed operation, even with severe CT saturation, using the SEL Adaptive Overcurrent Element.


Facilitate traditional or advanced protection schemes using SELogic® control equations with SELogic variables and timers. Remotely control overcurrent elements via serial communications.

Monitoring and Recording

Eliminate panel-mounted ammeters with accurate metering functions. Use front-panel display of metered secondary current magnitudes and phase angles to facilitate commissioning work. Review event reports to analyze protection scheme operations.

Application Settings

Accommodate a wide variety of transformer and CT connections, and automatically calculate the correct tap values with user-friendly relay settings. a cSELE r a t o r® QuickSet™ SEL-5030 Software simplifies settings creation and relay communications.


Choose from Modbus®, ASCII, and binary protocols for communications with SCADA, local HMI, or modems


487E 387E 387 387A 787 787-3E 787-3S 787-4X 587
Breaker Failure Protection f f f f
Transformer and Machine Current Differential
Low-Impedance Bus Differential
Underfrequency Load Shedding f +
Undervoltage Load Shedding f +
Three-Phase Current Inputs 5 3 4 2 2 3 3 4 2
Three-Phase Voltage Inputs 2 1 1+ 1 1
24 Overexcitation (Volts/Hertz) +
25 Synchronism Check
27/59 Under-/Overvoltage +
32 Directional Power +
46 Current Unbalance
49 Equipment Thermal Monitoring +
50FO Flashover Protection f f f f f f
50 (N,G) Overcurrent (Neutral, Ground)
50P Phase Overcurrent
50Q Negative-Sequence Overcurrent
51 (N,G) Time-Overcurrent (Neutral, Ground)
51P Phase Time-Overcurrent
51Q Negative-Sequence Time-Overcurrent
67 (P,G,Q) Directional Overcurrent (Phase, Ground, Neg. Seq.)
81 Under-/Overfrequency +
81R Change-in-Rate-of-Frequency f
87 Current Differential
REF Restricted Earth Fault + +
SELogic Control Equations
Voltage Check on Closing f f f
Transformer Cooling Fan Control f f f f f
Nonvolatile Latch Control Switches
SELogic Remote Control Switches
SELogic Local Control Switches
Display Points
Multiple Settings Groups
Substation Battery Monitor
Breaker Wear Monitor
Event Report (Multicycle Data)
Sequential Events Recorder
Instantaneous Meter
Demand Meter
Load and Temperature Profile Report
RTD (Resistance Temperature Detector) Inputs + + + +
Built-In Web Server
IEEE C37.118 Synchrophasors
IEC 61850 + + + + + +
IEC 60870-5-103 + + +
Simple Network Time Protocol (SNTP)
Parallel Redundancy Protocol (PRP)
Through-Fault Monitor +
2600 RTD Module Communications
Thermal Model +
Connectorized (Quick Disconnect) Available + + + + + + +
Standard Feature
+ Model Option
f This function may be created using settings

Product Literature