20130627

SEL-421 RelayProtection and

Automation System

Instruction Manual

Reference Manual

*PM421-03-NB*

SEL-421 Relay Reference Manual Date Code 20130627

20012013 by Schweitzer Engineering Laboratories, Inc. All rights reserved.

All brand or product names appearing in this document are the trademark or registered trademark of their respective holders. No SEL trademarks may be used without written permission. SEL products appearing in this document may be covered by U.S. and Foreign patents.

Schweitzer Engineering Laboratories, Inc. reserves all rights and benefits afforded under federal and international copyright and patent laws in its products, including without limitation software, firmware, and documentation.

The information in this document is provided for informational use only and is subject to change without notice. Schweitzer Engineering Laboratories, Inc. has approved only the English language document.

This product is covered by the standard SEL 10-year warranty. For warranty details, visit www.selinc.com or contact your customer service representative. PM421-03

Date Code 20130627 SEL-421 Relay

Table of ContentsTable of Contents................................................................................................................................................. i

List of Tables ...................................................................................................................................................... vii

List of Figures ................................................................................................................................................... xxi

Preface............................................................................................................................................................... xxxi

Users GuideSection 1: Introduction and Specifications

Features........................................................................................................................................................ U.1.2Models and Options..................................................................................................................................... U.1.5SEL-421 Versions and Supported Features ................................................................................................. U.1.7Applications................................................................................................................................................. U.1.8Specifications ............................................................................................................................................ U.1.13

Section 2: InstallationShared Configuration Attributes.................................................................................................................. U.2.1Plug-In Boards........................................................................................................................................... U.2.12Jumpers...................................................................................................................................................... U.2.18Relay Placement ........................................................................................................................................ U.2.30Connection................................................................................................................................................. U.2.31AC/DC Connection Diagrams ................................................................................................................... U.2.50

Section 3: PC SoftwareInstalling the Computer Software................................................................................................................ U.3.2Communications Setup................................................................................................................................ U.3.4Settings Database Management and Drivers ............................................................................................... U.3.6Create and Manage Relay Settings.............................................................................................................. U.3.9Expression Builder .................................................................................................................................... U.3.14Analyze Events .......................................................................................................................................... U.3.16HMI Meter and Control............................................................................................................................. U.3.21

Section 4: Basic Relay OperationsInspecting a New Relay............................................................................................................................... U.4.1Connecting and Applying Power................................................................................................................. U.4.3Establishing Communication....................................................................................................................... U.4.4Changing the Default Passwords ................................................................................................................. U.4.6Checking Relay Status............................................................................................................................... U.4.10Making Simple Settings Changes.............................................................................................................. U.4.13Examining Metering Quantities ................................................................................................................ U.4.33Reading Oscillograms, Event Reports, and SER....................................................................................... U.4.42Operating the Relay Inputs and Outputs ................................................................................................... U.4.56Configuring High-Accuracy Timekeeping ................................................................................................ U.4.71Readying the Relay for Field Application................................................................................................. U.4.79

Section 5: Front-Panel OperationsFront-Panel Layout ...................................................................................................................................... U.5.2Front-Panel Menus and Screens ................................................................................................................ U.5.13Front-Panel Automatic Messages.............................................................................................................. U.5.34Operation and Target LEDs....................................................................................................................... U.5.36Front-Panel Operator Control Pushbuttons ............................................................................................... U.5.40

ii

SEL-421 Relay Date Code 20130627

Table of Contents

Section 6: Testing and TroubleshootingTesting Philosophy ...................................................................................................................................... U.6.1Testing Features and Tools .......................................................................................................................... U.6.4Relay Test Connections ............................................................................................................................... U.6.8Test Methods ............................................................................................................................................. U.6.13Checking Relay Operation ........................................................................................................................ U.6.24Relay Self-Tests......................................................................................................................................... U.6.38Relay Troubleshooting .............................................................................................................................. U.6.42Factory Assistance..................................................................................................................................... U.6.45

Appendix A: Firmware and Manual VersionsFirmware..................................................................................................................................................... U.A.1Instruction Manual.................................................................................................................................... U.A.11

Applications HandbookSection 1: Protection Application Examples

Overview ..................................................................................................................................................... A.1.1230 kV Overhead Transmission Line Example........................................................................................... A.1.2500 kV Parallel Transmission Lines With Mutual Coupling Example ..................................................... A.1.18345 kV Tapped Overhead Transmission Line Example ............................................................................ A.1.51EHV Parallel 230 kV Underground Cables Example ............................................................................... A.1.84Out-of-Step Logic Application Examples ............................................................................................... A.1.115Auto-Reclose Example.