NEMA Standard addresses low voltage circuit breakers.

Press Release Summary:



NEMA has published NEMA AB 5-2011, which examines selective coordination at high levels of short circuit fault current in instantaneous region of circuit breaker time-current curve by use of selective coordination tools. Standard includes both molded case circuit breakers and insulated case circuit breakers, and is designed to insure that manufacturers are consistent in methods that they use in validating information that is published in selective coordination tools.



Original Press Release:



NEMA Publishes NEMA AB 5 Establishing Levels of Selective Coordination for Low Voltage Circuit Breakers



ROSSLYN, Va, -The National Electrical Manufacturers Association (NEMA) has published NEMA AB 5 Establishing Levels of Selective Coordination for Low Voltage Circuit Breakers.

AB 5-2011 examines selective coordination at high levels of short circuit fault current in the instantaneous region of the circuit breaker time-current curve by use of selective coordination tools. NEMA AB 5 includes molded case circuit breakers and insulated case circuit breakers, specifically instantaneous selective coordination at high levels of fault current. The intent of this standard is to insure that circuit breaker manufacturers are consistent in the methods that they use in validating the information that is published in selective coordination tools.

The contents and scope of AB 5-2011 may be viewed at www.nema.org/stds/ab-5.cfm. A hard or electronic copy may be purchased for $80 by visiting global.ihs.com or by contacting IHS at 800-854-7179 (U.S. only), 303-397-7956 (international), or 303-397-2740 (fax).

NEMA is the association of electrical equipment manufacturers, founded in 1926 and headquartered in Arlington, Virginia. Its member companies manufacture a diverse set of products including power transmission and distribution equipment, lighting systems, factory automation and control systems, and medical diagnostic imaging systems. Worldwide annual sales of NEMA-scope products exceed $120 billion.

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