Schweitzer Engineering Laboratories SEL-321 User manual

SEL-321
SEL-321-1
PHASE AND GROUND DISTANCE RELAY
DIRECTIONAL OVERCURRENT RELAY
FAULT LOCATOR
INSTRUCTION MANUAL
SCHWEITZER ENGINEERING LABORATORIES
2350 NE HOPKINS COURT
PULLMAN, WA USA 99163-5603
TEL: [phone] FAX: [phone]

!
CAUTION: The relay contains devices sensitive
to electrostatic discharge (ESD). When working
on the relay with front or top cover removed, work
surfaces and personnel must be properly grounded
or equipment damage may result.
!
ATTENTION: Le relais contient des pièces
sensibles aux décharges électrostatiques (DES).
Quand on travaille sur le relais avec le panneau
avant ou du dessus enlevé, les surfaces de travail
et le personnel doivent être mis à la terre
convenablement pour éviter les dommages à
l'équipement.
!
CAUTION: This procedure requires that you
handle components sensitive to Electrostatic
Discharge (ESD). If your facility is not equipped
to work with these components, we recommend
that you return the relay to SEL for firmware
installation.
!
ATTENTION: Cette procédure requiert que
vous manipuliez des composants sensibles aux
décharges électrostatiques (DES). Si vous n'êtes
pas équipés pour travailler avec ce type de
composants, nous vous recommandons de les
retourner à SEL pour leur installation.
!
CAUTION: Verify proper orientation of any
replaced Integrated Circuit(s) (ICs) before
reassembling the relay. Energizing the relay with
an IC reversed irrecoverably damages the IC. If
you mistakenly reenergize the relay with an IC
reversed, do not place the relay in service using
that IC, even if you correct the orientation.
!
ATTENTION: Vérifier l'orientation d’un circuit
intégré (CI) que vous remplacez avant de l’
installer sur le relais. La mise sous-tension du
relais avec un CI inversé endommagera de façon
irréversible celui-ci. Si vous remettez le relais
sous tension par mégarde, ne pas laisser le relais
en service avec ce CI, même si l'orientation a été
corrigée.
!
CAUTION:Never work on the SEL-321 with
the front or top cover removed, when the SEL-321
is energized.
!
ATTENTION: Ne jamais travailler sur le
SEL-321 avec le panneau avant ou du dessus
enlevé, quand le SEL-321 est sous-tension.
!
WARNING: Do not rely upon pins 5 and 9 for
safety grounding, because their current-carrying
capacity is less than control power short circuit
and protection levels
!
AVERTISSEMENT: Ne pas se fier aux broches
5 et 9 pour une mise à la terre sécuritaire: leur
limite de support en courant est inférieure au
niveau de court-circuit assuré par la protection.
!
WARNING: Use only serial communications
cables manufactured by SEL or built to SEL
specifications with the SEL-321 Relay. Damage
to the relay or your communication equipment
may result from the use of incorrect
communication connections.
!
AVERTISSEMENT: N’utiliser que des câbles
de communication série produits par SEL ou
conformes à ses spécifications avec le relais
SEL-321. Des dommages au relais ou à
l’équipement de communication pourraient
survenir à la suite de mauvais raccordements.
!
WARNING: This device is shipped with default
passwords. Default passwords should be changed
to private passwords at installation. Failure to
change each default password to a private
password may allow unauthorized access. SEL
shall not be responsible for any damage resulting
from unauthorized access.
!
AVERTISSEMENT: Cet équipement est
expédié avec des mots de passe par défaut. A
l'installation, les mots de passe par défaut devront
être changés pour des mots de passe confidentiels.
Dans le cas contraire, un accès non-autorisé à
l'équipement pourrait être possible. SEL décline
toute responsabilité pour tout dommage résultant
de cet accès non-autorisé.
The software (firmware), schematic drawings, relay commands, and relay messages are copyright protected by the United States Copyright Law and
International Treaty provisions. ll rights are reserved.
You may not copy, alter, disassemble, or reverse-engineer the software. You may not provide the software to any third party.
ll brand or product names appearing in this document are the trademark or registered trademark of their respective holders.
Schweitzer Engineering Laboratories, SELOGIC, Connectorized, CSELER TOR, Job Done, SEL-PROFILE, and are registered trademarks of Schweitzer Engineering
Laboratories.
The English language manual is the only approved SEL manual.
Copyright © SEL 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 ( ll rights reserved) Printed in US .
This product is covered by U.S. Patent Numbers: 4,996,624; 5,041,737; 5,208,545; 5,262,679; 5,317,472; 5,325,061; 5,349,490; 5,365,396; 5,367,426; 5,479,315;
5,515,227; 5,790,418; 5,793,750; 5,883,578; and U.S. Patent(s) Pending, and Foreign Patent(s) Issued and Pending.
This product is covered by the standard SEL 10-year warranty. For warranty details, visit www.selinc.com or contact your customer service representative.

Date Code 20011026 Preface Preface-1
SEL-321/321-1 Instruction Manual
PREFACE
This manual applies to multiple versions of the SEL-321 and SEL-321-1 Relays (designed to
operate with nominal system frequencies of 50 Hz and 60 Hz). Except when specific differences
are noted, all specifications and data apply equally to all versions of the relay.
SEL-321 RELAY VS SEL-321-1 RELAY
Throughout this manual where there are differences between the SEL-321 Relay and the
SEL-321-1 Relay the headings of those sections that apply strictly to the SEL-321-1 Relay
include the following statement:
(SEL-321-1 Relay Only)

Date Code 20011203 Manual Change Information i
SEL-321/321-1 Instruction Manual
MANUAL CHANGE INFORMATION
The date code at the bottom of each page of this manual reflects the creation or revision date.
Date codes are changed only on pages that have been revised and any following pages affected
by the revisions (i.e., pagination). If significant revisions are made to a section, the date code on
all pages of the section will be changed to reflect the revision date.
Each time revisions are made, both the main table of contents and the affected individual section
table of contents are regenerated and the date code is changed to reflect the revision date.
Changes in this manual to date are summarized below (most recent revisions listed at top).
Revision
Date Summary of Revisions
The Manual Change Information section has been created to begin a record of revisions to
this manual. All changes will be recorded in this Summary of Revisions table.
20011203 Appendix A:
- Fix for TCM logic bug.
20011026 Reissued entire manual to reflect the following changes:
Section 2:
- Settings 59QL and 59PL are no longer hidden when ELOP = N1, Y1, or Y2.
- Corrected Figure 2.31: Permissive Overreaching Transfer Trip Scheme
Logic.
Section 3:
- Clarified PULSE n t command.
- Updated screen capture text in subsection SET P.
Section 5:
- Corrected typographical error in subsection Original Loss-of-Potential
Logic.
- Corrected Z1ANG and Z0ANG settings ranges in the Settings Sheets.
- Added MIRRORED BITS settings to Settings Sheets.
Section 6:
- Corrected typographical error in subsection IRIG-B Input Connection.
Section 7:
- Corrected typographical errors.
Appendix A:
- Improved frequency tracking algorithm.
- Availability of 59Q and 59P elements when advanced LOP is enabled.

ii Manual Change Information Date Code 20011203
SEL-321/321-1 Instruction Manual
Revision
Date Summary of Revisions
20010215 Reissued entire manual to reflect the following changes:
Updated to new manual format.
Section 2:
- Updated Power Supply information.
Minor corrections made in Appendix A.
20000721 Updated Section 2: Specifications with new k0 range and LOP logic. Updated
Figure 2.22: Negative Sequence Directional Logic and Figure 2.38: Loss-of-
Potential Logic.
Added vector error information in Table 3.13.
Updated Section 5: Applications with new LOP settings and Settings Sheets
with new LOP settings and k0 range.
Updated Section 7: Testing and Maintenance with new LOP references and
updated Firmware Upgrade Instructions.
Updated Appendix A: Firmware Versions. New k0 range, LOP logic and IEC
1000-4-5 compliance for SEL-321-1.
991102 Updated Figure 2.4 and deleted Burn-In information in Section 2:
Specifications.
991022 Updated Section 3: Communications and 321-1 Command Summary to reflect
correct page layout and MIRRORED BITS™ format.
Reissued page 6.2 in Section 6: Installation due to typographical error (no date
code change).
Updated Appendix A: Firmware Versions: Improved MIRRORED BITS and
Fast Meter communications.
990614 Updated MIRRORED BITS format throughout to reflect new trademark.
Deleted the Optional jumper-selectable inputs from Section 2: Specifications.
Deleted the Configure the Control Input Voltage subsection and reference to
the control input voltage under the Set Jumpers subsection in Section 6:
Installation.
Deleted the Control Input Voltage subsection in Appendix I: Interface Board
Specifications and renumbered figures.

Date Code 20011203 Manual Change Information iii
SEL-321/321-1 Instruction Manual
Revision
Date Summary of Revisions
990331 Section 3: Communications: Updated Tables 3.11 and 3.12 in to include MB8
protocol. Changed ®to ¯on page 3-43.
Appendix H: Updated to include MB8 protocol.
Section 6: Installation: Updated figure captions for Figures 6.2, 6.4, and 6.12.
Deleted Figure 6.11. Renumbered subsequent figures.
Section 2: Specifications: Changed variables “(X, Y, Z, W, or Z)” to the
correct variables “(V, W, X, Y, or Z)” listed on page 2-22.
Appendix A: Changed “event reported” to the correct “event reports” on
page A-9.
Appendix I: Replaced Figure I.15.
981030 Updated Figure 1.3 in Section 1: Introduction to reflect new current
transformer shorting connector.
Incorporated “Electronic-Level Input Option” addendum into Section 1:
Introduction.
Added front and rear panel drawings, Figure 6.11: SEL-321 Relay Horizontal
Front and Rear Panel Drawings (One I/O Board Plug-In Connector Version;
16 high-current interrupting outputs with shared return terminals) in
Section 6: Installation.
Replaced Figures 6.13, 6.14, 6.15, and 6.16 in Section 6: Installation with
Figures 6.14 and 6.15.
Revised manual to change model references for the current transformer shorting
connector and for respective wiring harness part numbers. See Note, Rear-
Panel Plug-In Connectors Option (Figure 6.10 through Figure 6.13),
Section 6.
Corrected pagination on pages 7-17 through 7-24.
Revised Figure B.1 in Appendix B: SEL-321 Main Board Jumper, Connector,
and Socket Locations.
980812 Updated Appendix A: Firmware Versions. Improved diagnostics.
980715 Updated Appendix A: Firmware Versions.
980529 Updated Appendix A: Firmware Versions. Changed series compensation
logic. Changed long memory constant time to 31.75 cycles.
980320 Updated hardware references throughout entire manual.
Changed ERESTART default to Y.
Revised Section 6: Installation.
Added low-level test interface to Section 7: Maintenance and Testing.
Revised Figure 3.1.
Added Appendix I: Interface Board Specifications.

iv Manual Change Information Date Code 20011203
SEL-321/321-1 Instruction Manual
Revision
Date Summary of Revisions
980224 Added relay elements:
RBAD, CBAD, LBOK in Figure 2.7 and Figure 2.8 and MIRBRK, MIRFRA,
MIRPAR, MIROVR, MIRIN, MIRSYC, MIRDAT, MIRDIS in Figure 2.22
and Figure 2.23 in the Relay Elements subsection in Section 2:
Specifications.
Mirrored Bits related port settings changes in Table 2.27 in the
Communications Ports Specifications subsection in Section 2:
Specifications.
Corrected label of the 67Q2SD timer in Figure 2.27 and the 67N2SD timer in
Figure 2.28 in the General Specifications subsection in Section 2:
Specifications.
Added COM and LOOP commands in Figure 3.1 in the Command
Characteristics subsection in Section 3: Communications.
Added COM and LOOP commands, revised Table 3.11 and Table 3.12 for
new Mirrored Bits settings requirements, corrected target number ranges in
TARGET command description and Table 3.15, fixed the arrows in Table
3.18 and Table 3.19, all in the Description of Commands subsection in
Section 3: Communications.
Corrected the EBLKD and ETDPU settings prompts in the Settings Sheet for
SEL-321 Relay Setting Example subsection in Section 5: Applications.
Corrected Equation 7.18 in the Ground Quadrilateral Distance Element
Reactive Reach Test Using Three Voltage Sources and One Current Source
subsection in Section 7: Maintenance and Testing.
Modified SEL-321 Relay Command Summary card stock insert to include
COMM and LOOP commands.
Added SEL-321-1 Target Information card stock insert.
Added Appendix H: Mirrored Bits.

Date Code 20011203 Table of Contents i
SEL-321/321-1 Instruction Manual
SEL-321/SEL-321-1 INSTRUCTION MANUAL
TABLE OF CONTENTS
SECTION 1: INTRODUCTION
SECTION 2: SPECIFICATIONS
SECTION 3: COMMUNICATIONS
SECTION 4: EVENT REPORTING
SECTION 5: APPLICATIONS
SECTION 6: INSTALLATION
SECTION 7: MAINTENANCE AND TESTING
SECTION : APPENDICES
Appendix A: Firmware Versions in This Manual
Appendix B: SEL-321 Main Board Jumper, Connector, and Socket
Locations
Appendix C: Application Guidelines
Appendix D: ONEBUS: Program to Compute Test Set Settings for
Testing Distance Relays
Appendix E: SEL-5601 Analytic Assistant
Appendix F: Special Application Settings
Appendix G: Additional SEL-321-1 Relay Communications Protocol
Appendix H: MIRRORED BITS™ Communications
Appendix I: Interface Board Specifications
SEL-321-1 TARGET INFORMATION
SEL-321 RELAY COMMAND SUMMARY
SEL-321-1 RELAY COMMAND SUMMARY

Date Code 20011026 Introduction i
SEL-321/321-1 Instruction Manual
TABLE OF CONTENTS
SECTION 1: INTRODUCTION .................................................................1-1
Getting Started ..............................................................................................................................1-1
Overview.......................................................................................................................................1-1
Event Reporting ....................................................................................................................1-5
Applications Highlights ........................................................................................................1-6
Other Features.......................................................................................................................1-7
Electronic-Level Input Option ..............................................................................................1-7
Maximum Continuous Rating ....................................................................................... 1-8
Relay Test System (RTS)..............................................................................................1-8
FIGURES
Figure 1.1: SEL-321 Front Panel (One I/O Board Version) ...................................................................1-2
Figure 1.2: SEL-321 Rear Panel (One I/O Board Version, showing conventional terminal
blocks – other options are available)..............................................................................1-2
Figure 1.3: SEL-321 Rear Panel (Two I/O Board Version, showing plug-in connectors option -
other options are available)............................................................................................1-3
Figure 1.4: Three-Phase and Phase-Phase Distance Characteristics.......................................................1-3
Figure 1.5: Ground Distance Characteristics ..........................................................................................1-4
Figure 1.6: Instantaneous, Definite-Time, and Time-Overcurrent Characteristics.................................1-4
Figure 1.7: SELOGIC®Control Equations Programmable Control Logic ...............................................1-5
Figure 1.8: SEL-5601 Analytic Assistant ...............................................................................................1-5

Date Code 20011026 Introduction 1-1
SEL-321/321-1 Instruction Manual
SECTION 1: INTRODUCTION
GETTING STARTED
This instruction manual provides descriptive information and instructions for the SEL-321/321-1
Relay. The instructions in this manual are designed for use by personnel with a background in
power engineering and experienced in protective relay applications. A detailed technical
description of the relay and examples of its application are included. While reasonable examples
and illustrations of relay uses are given, sound judgment must be exercised at all times in its
application.
The manual is divided into sections with the following information:
Section 1: Introduction General information
Section 2: Specifications Detailed technical description of each feature
Section 3: Communications User interface and protocol
Section 4: Event Reporting Describes content and use
Section 5: Applications How to apply and set
Section 6: Installation Wiring and configuration
Section 7: Maintenance and Testing Initial checkout and tests
Section 8: Appendices
OVERVIEW
The following pages present a brief overview of the functions and characteristics of the relay.

1-2 Introduction Date Code 20011026
SEL-321/321-1 Instruction Manual
From Front Panel:
• Set relay • Switch setting groups
• Read meter and other data • Password protection
Figure 1.1: SEL-321 Front Panel (One I/O Board Version)
Figure 1.2: SEL-321 Rear Panel (One I/O Board Version, showing conventional terminal
blocks – other options are available)

Date Code 20011026 Introduction 1-3
SEL-321/321-1 Instruction Manual
Figure 1.3: SEL-321 Rear Panel (Two I/O Board Version, showing plug-in connectors
option - other options are available)
Figure 1.4: Three-Phase and Phase-Phase Distance
Characteristics
• Four mho zones
• Two quadrilateral zones
for OOS
• Two load zones
• Set only characteristics
you need
• All zones reversible

1-4 Introduction Date Code 20011026
SEL-321/321-1 Instruction Manual
Figure 1.5: Ground Distance Characteristics
• Four mho zones
• Four quadrilateral zones
• Use quadrilateral, mho,
none, or both
Figure 1.6: Instantaneous, Definite-Time, and Time-
Overcurrent Characteristics
• Four US, four IEC curve
families
• Phase, residual, and
negative-sequence
elements
• Torque-controllable by
distance and directional
elements
• One-cycle or electro-
mechanical reset char-
acteristics
• Four instantaneous/
definite-time elements for
negative-sequence and
for residual overcurrent

Date Code 20011026 Introduction 1-5
SEL-321/321-1 Instruction Manual
Figure 1.7: SELOGIC®Control Equations Programmable
Control Logic
• Assign input functions
• Create output functions
specific to any applica-
tion
• Design unique trip and
control schemes
• Minimize external timers,
auxiliary relays, wiring,
and panel space
• Event reporting records
all logic
67Q4
67Q2
67Q1
27L
ZLOAD
0
2500
0
250
-5000
0
5000
0 4 8 12
IA IB ICVA VB VC3I0 3I1 3I2Digitals
Cycles
IA IB IC VA VB
VC 3I0 3I1 3I2
Figure 1.8: SEL-5601 Analytic Assistant
• Oscillographic displays
using the SEL-5601
Analytic Assistant and 16
samples/cycle data
• Condensed 4 samples/
cycle reporting
• Full report gives com-
plete state of inputs,
outputs, and elements
every 1/16-cycle
• Read the ASCII text
format with any computer
– no proprietary formats
are used
Event Reporting
Provides four types of event reports:
• Automatic summary report with abbreviated information
• Default report is 11-cycles duration, 4 samples/cycle
• Long event report is 11-cycles duration, 16 samples/cycle
• Unfiltered report for computer analysis of data
• Forty summaries are stored in nonvolatile memory

1-6 Introduction Date Code 20011026
SEL-321/321-1 Instruction Manual
App ications High ights
A list of applications and key specifications:
Applications Key Specifications
Series Compensated Lines • Positive-sequence memory polarization
• Long memory duration for directional stability
Single-Pole Tripping • Advanced phase-selection methods
• Secure protection during open-pole interval
• Pole-discordance logic trips three-pole for
excessive single-pole-open events
Multiple-Breaker Applications • SPT one; 3PT other
• SPT both; 3PT both
• Trip coil monitors for up to six poles
• Stub protection
Long Lines • Load-encroachment elements prevent
unwanted trips on load
• Voltage elements detect local and remote bus
overvoltages
• Sensitive negative-sequence and residual over-
current elements provide sensitive backup
protection
Tapped and Three-Terminal Lines • Four zones
• Two zero-sequence compensation factors for
more accurate ground-distance reach on either
side of tap
• Independent reach settings for phase, ground
mho, and ground reactance elements
• Multiple setting groups cover any switching
configurations
Bus-Tie Breakers • Multiple setting groups
− match relay settings group to each line
substitution
− eliminate current reversing switches
• Local or remote operator switches the setting
groups
Subtransmission Lines • Time-stepped distance
• Ground directional overcurrent protection
• Torque controlled time-overcurrent elements
Lines with Transformers • Negative-sequence overcurrent protection
Lines with Reactors • Overvoltage elements control reactor insertion
and tripping

Date Code 20011026 Introduction 1-7
SEL-321/321-1 Instruction Manual
Applications Key Specifications
Short Transmission Lines • Twenty-cycle polarizing memory duration
Permissive Overreaching Transfer
Tripping Schemes (POTT)
• Current reversal guard logic
• Open breaker echo keying logic
• Weak- and zero-infeed logic
• Time-step distance backup
Directional Comparison Unblocking
Tripping Schemes (DCUB)
• Includes all POTT logic
• All loss-of-channel logic inside the relay
• Time-step backup
Permissive Underreaching Transfer
Tripping Schemes (PUTT)
• Supported by POTT logic
• Time-step backup
Directional Comparison Blocking Trip
Scheme (DCB)
• Current reversal guard logic
• Carrier coordinating timers
• Carrier send and receive extend logic
• Zone 3 latch eliminates the need for offset
three-phase distance elements
• Time-step backup
Zone 1 Extension Schemes • Settable Zone 1 extension multiplier
• Settable Zone 1 extension enable delay
Direct Underreaching Transfer
Tripping Schemes (DUTT)
• SELOGIC control equations program which
elements key direct trip
Other Features
• Fault locator
• Metering
• Automatic self-testing
• Forty event report summaries stored in non-volatile memory
• Three general purpose timers
• Five choices for controlling the trip circuits
• Trip circuit monitoring
• Hardware options for inputs, output contacts, and rear-panel terminals
E ectronic-Leve Input Option
The SEL relay instruction manuals address standard current (1 or 5 A) and voltage (67 V) inputs.
If you ordered your SEL relay with an electronic-level input option, references in the instruction
manual to Current Inputs and Voltage Inputs should be noted accordingly. Since the input
circuits are designed to accept electronic levels, do not subject them to Dielectric Strength,

1-8 Introduction Date Code 20011026
SEL-321/321-1 Instruction Manual
Interference, or Impulse Tests. Stickers on the rear of the relay indicate which inputs should only
be connected to low-level electronic sources. We recommend that you use twisted-shielded-pair
(TSP) cable between the source and relay and that you ground the shield at one end of the cable.
The SEL-321 Relay provides several electronic-level input options. Option A provides the best
accuracy in each case. The 1.314 V secondary input-voltage option should be used in most
applications. Determine your secondary input-current option by multiplying your 1 per-unit
primary current by the sensor scaling factor.
Examples: Secondary Input-Voltage Option = 1.314 V
1 PU = 2000 A, Sensor Scaling Factor = 0.1 mV/A
Secondary Input-Current Option = 2000+0.1 = 200 mV
Since the SEL-321 Relay is set in secondary quantities and nonconventional sensor outputs are in
primary quantities you must scale the relay settings using PTR (Potential Transformer Ratio) and
CTR (Current Transformer Ratio). Determine the PTR setting by dividing the primary line-
neutral voltage by 67 V. The CTR is determined by dividing your 1 per-unit primary current by
5 A. Use the PTR and CTR to determine the settings in secondary quantities.
Examples: PTR = (525 kVL-L)/(√3+67) = 4524 ≈4500
CTR = 2000/5 = 400
Maximum Continuous Rating
Input: 15 Vpeak ≈10.6 Vrms
Re ay Test System (RTS)
The SEL-RTS Relay Test System is designed to bypass a relay's internal CTs and PTs (or
low-level input module) so that it can provide low-level signals directly to the relay's processing
module. You can use the SEL-RTS to test a relay's low-level input module at the terminal screws
by modifying Scale Factors in the SELTESTTM Configuration Window. To determine the current
channel ratio, divide 5 A by the secondary 1 PU input. To determine the voltage channel ratio,
divide 67 V by the secondary 1 PU input.
Examples: (5 A)/(200 mV) = 25
(67 V)/(1.314 V) = 50.99 ≈51