20160715

SEL-351SProtection System

Instruction Manual

*PM351S-02-NB*

SEL-351S Protection System Instruction Manual Date Code 20160715

20092016 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 selinc.com or contact your customer service representative. PM351S-02

http://selinc.com/

Date Code 20160715 Instruction Manual SEL-351S Protection System

Table of ContentsList of Tables ........................................................................................................................................................................vii

List of Figures ....................................................................................................................................................................xiii

Preface ................................................................................................................................................................................... xxi

Section 1: Introduction and SpecificationsSEL-351S Models ........................................................................................................................................... 1.1Applications..................................................................................................................................................... 1.3Specifications .................................................................................................................................................. 1.4

Section 2: InstallationOverview ......................................................................................................................................................... 2.1Relay Mounting ............................................................................................................................................... 2.1Front-Panel and Rear-Panel Connection Diagrams......................................................................................... 2.3User-Configurable Label Option for the Front Panel ...................................................................................... 2.7Making Rear-Panel Connections ..................................................................................................................... 2.7Making Communications Connections ......................................................................................................... 2.16SEL-351S AC/DC Connection Diagrams for Various Applications ............................................................. 2.20Circuit Board Connections and Jumpers ....................................................................................................... 2.34

Section 3: Overcurrent, Harmonic Blocking, Voltage, Synchronism Check, Frequency, and Power Elements

Overview ......................................................................................................................................................... 3.1Instantaneous/Definite-Time Overcurrent Elements ....................................................................................... 3.1Time-Overcurrent Elements .......................................................................................................................... 3.16Second Harmonic Blocking Logic ................................................................................................................ 3.26Voltage Elements ........................................................................................................................................... 3.29Synchronism-Check Elements....................................................................................................................... 3.36Frequency Elements ...................................................................................................................................... 3.55Rate-of-Change-of-Frequency (81R) Protection ........................................................................................... 3.61Voltage Sag, Swell, and Interruption Elements ............................................................................................. 3.63Power Elements ............................................................................................................................................. 3.68

Section 4: Loss-of-Potential, Load-Encroachment, and Directional Element LogicOverview ......................................................................................................................................................... 4.1Loss-of-Potential Logic ................................................................................................................................... 4.2Load-Encroachment Logic .............................................................................................................................. 4.8Directional Control for Neutral-Ground and Residual-Ground Overcurrent Elements ................................ 4.14Directional Control for Negative-Sequence and Phase Overcurrent Elements ............................................. 4.35Directional Control Settings .......................................................................................................................... 4.43Directional Control Provided by Torque Control Settings ............................................................................ 4.69

Section 5: Trip and Target LogicOverview ......................................................................................................................................................... 5.1Trip Logic ........................................................................................................................................................ 5.1Switch-Onto-Fault (SOTF) Trip Logic............................................................................................................ 5.9Communications-Assisted Trip LogicGeneral Overview.......................................................................... 5.13Permissive Overreaching Transfer Trip (POTT) Logic ................................................................................. 5.17Directional Comparison Unblocking (DCUB) Logic.................................................................................... 5.22Directional Comparison Blocking (DCB) Logic........................................................................................... 5.27Breaker Failure Protection............................................................................................................................. 5.31Front-Panel Target LEDs............................................................................................................................... 5.34

ii

SEL-351S Protection System Instruction Manual Date Code 20160715

Table of Contents

Section 6: Close and Reclose LogicOverview..........................................................................................................................................................6.1Breaker Status Logic........................................................................................................................................6.2Close Logic ......................................................................................................................................................6.2Reclose Supervision Logic ..............................................................................................................................6.6Reclosing Relay .............................................................................................................................................6.13

Section 7: Inputs, Outputs, Timers, and Other Control LogicOverview..........................................................................................................................................................7.1Optoisolated Inputs ..........................................................................................................................................7.2Local Control Switches....................................................................................................................................7.5Remote Control Switches ................................................................................................................................7.9Latch Control Switches..................................................................................................................................7.11Multiple Setting Groups.................................................................................................................................7.17SELOGIC Control Equation Variables/Timers................................................................................................7.26Logic Variables ..............................................................................................................................................7.30Virtual Bits ..................