Table of Contents

Chapter 1 - Introduction
  1.1 Scope
  1.2 Definitions
  1.3 Acronyms and abbreviations
  1.4 Bibliography
  1.5 Manufacturers' data sources
Chapter 2 - Description of a short-circuit current
  2.1 Introduction
  2.2 Available short-circuit
  2.3 Symmetrical and asymmetrical currents
  2.4 Short-circuit calculations
  2.5 Total short-circuit current
  2.6 Why short-circuit currents are asymmetrical
  2.7 DC component of short-circuit currents
  2.8 Significance of current asymmetry
  2.9 The application of current asymmetry information
  2.10 Maximum peak current
  2.11 Types of faults
  2.12 Arc resistance
  2.13 Bibliography
Chapter 3 - Calculating techniques
  3.1 Introduction
  3.2 Fundamental principles
  3.3 Short-circuit calculation procedure
  3.4 One-line diagram
  3.5 Per-unit and ohmic manipulations
  3.6 Network theorems and calculation techniques
  3.7 Extending a three-phase short-circuit calculation
       procedures program to calculate short-circuit
       currents for single-phase branches
  3.8 Representing transformers with non-base voltages
  3.9 Specific time period and variations on fault
       calculations
  3.10 Determination of X/R ratios for ANSI fault calculations
  3.11 Three winding transformers
  3.12 Duplex reactor
  3.13 Significant cable lengths
  3.14 Equivalent circuits
  3.15 Zero sequence line representation
  3.16 Equipment data required for short-circuit calculations
  3.17 Bibliography
Chapter 4 - Calculating short-circuit currents for systems
            without ac delay
  4.1 Introduction
  4.2 Purpose
  4.3 ANSI guidelines
  4.4 Fault calculations
  4.5 Sample calculations
  4.6 Sample computer printout
  4.7 Conclusions
  4.8 Bibliography
Chapter 5 - Calculating ac short-circuit currents for systems
            with contributions from synchronous machines
  5.1 Introduction
  5.2 Purpose
  5.3 ANSI guidelines
  5.4 Fault calculations
  5.5 Nature of synchronous machine contributions
  5.6 Synchronous machine reactances
  5.7 One-line diagram data
  5.8 Sample calculations
  5.9 Sample computer printout
  5.10 Sample computer printout for larger system calculations
  5.11 Conclusions
  5.12 Bibliography
Chapter 6 - Calculating ac short-circuit currents for systems
            with contributions from induction motors
  6.1 Introduction
  6.2 Purpose
  6.3 ANSI guidelines
  6.4 Fault calculations
  6.5 Nature of induction motor contributions
  6.6 Large induction motors with prolonged contributions
  6.7 Data accuracy
  6.8 Details of induction motor contribution calculations
       according to ANSI standard application guides
  6.9 Recommended practice based on ANSI-approved standards
       for representing induction motors in multi-voltage
       system studies
  6.10 One-line diagram data
  6.11 Sample calculations
  6.12 Sample computer printout
  6.13 Bibliography
Chapter 7 - Capacitor contributions to short-circuit currents
  7.1 Introduction
  7.2 Capacitor discharge current
  7.3 Transient simulations
  7.4 Summary
  7.5 Bibliography
Chapter 8 - Static converter contributions to short-circuit
            currents
  8.1 Introduction
  8.2 Definitions of converter types
  8.3 Converter circuits and their equivalent parameters
  8.4 Short-circuit current contribution from the dc system
       to an ac short circuit
  8.5 Analysis of converter dc faults
  8.6 Short circuit between the converter dc terminals
  8.7 Arc-back short circuits
  8.8 Examples
  8.9 Conclusions
  8.10 Bibliography
Chapter 9 - Calculating ac short-circuit currents in
            accordance with ANSI-approved standards
  9.1 Introduction
  9.2 Basic assumptions and system modelling
  9.3 ANSI recommended practice for ac decrement modelling
  9.4 ANSI practice for dc decrement modelling
  9.5 ANSI-conformable fault calculations
  9.6 ANSI-approved standards and interrupting duties
  9.7 One-line diagram layout and data
  9.8 First cycle duty sample calculations
  9.9 Interrupting duty sample calculations
  9.10 Applying ANSI calculations to non-60 Hz systems
  9.11 Normative references
  9.12 Bibliography
Chapter 10 - Application of short-circuit interrupting
             equipment
 10.1 Introduction
 10.2 Purpose
 10.3 Application considerations
 10.4 Equipment data
 10.5 Fully rated systems
 10.6 Low voltage series rated equipment
 10.7 Low voltage circuit breaker short-circuit capabilities
       less than rating
 10.8 Equipment checklist for short-circuit currents
       evaluation
 10.9 Equipment phase duty calculations
 10.10 Equipment ground fault duty calculations
 10.11 Capacitor Switching
 10.12 Normative references
Chapter 11 - Unbalanced short-circuit currents
 11.1 Introduction
 11.2 Purpose
 11.3 ANSI guidelines
 11.4 Procedure
 11.5 Connection of sequence networks
 11.6 Sample calculations
 11.7 Conclusions
 11.8 Bibliography
Chapter 12 - Short-circuit calculations under international
             standards
 12.1 Introduction
 12.2 System modelling and methodologies
 12.3 Voltage factors
 12.4 Short circuit currents per IEC 60909
 12.5 Short circuits "far from generator"
 12.6 Short circuits "near generator"
 12.7 Influence of the motors
 12.8 Fault calculations in complex systems
 12.9 Comparing the ANSI-approved standards with IEC 909
 12.10 Sample calculations
 12.11 Normative references
 12.12 Bibliography

Abstract

Explains short-circuit current information including calculated short-circuit current duties for the application in industrial plants and commercial buildings, at all power system voltages, of power system equipment that senses, carries, or interrupts short-circuit currents.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	Institute of Electrical & Electronics Engineers
Pages
ISBN
Supersedes	IEEE DRAFT 551 : D5 2005