Sel SEL-487E-3 User Manual

Schweitzer Engineering Laboratories, Inc. SEL-487E-3, -4 Data Sheet
Three-Phase Transformer Protection,
Automation, and Control System
Key Features and Benefits
The SEL-487E Transformer Protection Relay provides three-phase differential protection for transformer applications
with as many as six three-phase restraint current inputs. A second three-phase differential element is also supported for
busbar protection.
➤ High-Speed Differential Protection. A two-stage slope adapts automatically to external fault conditions, providing
fast, sensitive, dependable, and secure differential protection, even for CT saturation and heavily distorted waveforms.
Two independent differential zones are available, one of which supports additional features that accommodate
transformer differential protection.
➤ Inrush and Overexcitation Detection. Combined harmonic blocking and restraint features provide maximum
security during transformer magnetizing inrush conditions. Waveshape-based inrush detection addresses inrush
conditions that contain low second and fourth harmonic content.
➤ Turn-to-Turn Winding Fault Protection. Innovative negative-sequence differential elements provide transformer
windings protection from as little as two percent turn-to-turn winding faults.
➤ Restricted Earth Fault Protection. Three independent REF elements provide sensitive protection for faults close
to the winding neutral in grounded wye-connected transformers.
SEL-487E-3, -4 Transformer
Protection Relay

Sel SEL-487E-3 Specifications

General

Type	Protection Relay
Frequency	50/60 Hz
Current Rating	5 A
Communication Protocols	DNP3, Modbus
Operating Temperature	-40°C to +85°C
Weight	1.4 kg
Functions	Overcurrent
Category	Protective Relay
Device Type	SEL-487E

Summary

Key Features and Benefits

High-Speed Differential Protection

Provides fast, sensitive, dependable, and secure differential protection for transformer applications.

Inrush and Overexcitation Detection

Offers harmonic blocking and restraint for security during transformer magnetizing inrush.

Restricted Earth Fault Protection

Provides sensitive protection for faults close to the winding neutral in grounded wye transformers.

Distance Protection

Protects transformers and transmission lines with four zones of phase and ground distance elements.

Ethernet Access

Grants access to all relay functions via optional Ethernet card for system interconnection.

Automation

Features enhanced automation with programmable elements for local and remote control.

Rules-Based Settings Editor

Allows relay setting and fault record analysis using an ASCII terminal or QuickSet.

Functional Overview

Protection Features

Details the various protection elements offered by the SEL-487E relay.

Applications

Describes how the SEL-487E can be applied in various transformer protection scenarios.

Additional Features

Covers the front-panel display, bay control, and other user interface capabilities.

Communications Features

Explains the relay's communication capabilities via Ethernet, serial ports, and protocols.

Automation

Highlights flexible control logic, integration, and SELOGIC equation capabilities.

Metering and Monitoring

Details the relay's metering, event reporting, and SER features for analysis.

Diagrams and Dimensions

Presents physical layouts, front panel views, and dimensional information.

Models and Options

Discusses available chassis sizes, firmware, and interface board options.

Specifications

Provides detailed technical specifications for all relay parameters and capabilities.