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0551-2006_VioletBook_frontCover

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551™
IEEE Recommended Practice for

Calculating
Short-Circuit
Currents in
Industrial and
Commercial
Power Systems

Published by the
Institute of Electrical and
Electronics Engineers, Inc.

IEEE Std 551™-2006

Recognized as an
American National Standard (ANSI)

IEEE Std 551™-2006

IEEE Recommended Practicefor Calculating Short-Circuit
Currents in Industrial and
Commercial Power Systems

Sponsor

Power Systems Engineering Committee
of the
IEEE Industry Applications Society
Approved 9 May 2006

IEEE-SA Standards Board
Approved 2 October 2006

American National Standards Institute

Abstract: This recommended practice provides short-circuit current information
including calculatedshort-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. Equipment
coverage includes, but should not be limited to, protective device sensors such as
series trips and relays, passive equipment that may carry short-circuit current such
as bus,cable, reactors and transformers as well as interrupters such as circuit
breakers and fuses.
Keywords: available fault current, circuit breaker, circuit breaker applications,
fuse, power system voltage, reactors, short-circuit applications guides, shortcircuit duties

The Institute of Electrical and Electronics Engineers, Inc.
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Copyright © 2006 bythe Institute of Electrical and Electronics Engineers, Inc.
All rights reserved. Published 17 November 2006. Printed in the United States of America.
IEEE is a registered trademark in the U.S. Patent & Trademark Office, owned by the Institute of Electrical and Electronics Engineers, Incorporated.
National Electrical Code and NEC are registered trademarks in the U.S. Patent & Trademark Office,owned by the National Fire Protection Association.
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ISBN 0-7381-4932-2 SH95520
ISBN 0-7381-4933-0 SS95520

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