Hansen and Cline's Paper Accepted for Publication in IEEE IAS Proceedings


NEWBURYPORT, Mass. (October 14, 2009) - The paper, Selectivity Analysis in Low Voltage Power Distribution Systems with Fuses and Circuit Breakers, has been accepted for publication in the IEEE IAS Proceedings. Co-authored by Steve Hansen and Cindy Cline of Ferraz Shawmut and Marcelo Valdes, PE and Tom Papallo of GE Consumer & Industrial, the paper was also presented at the I & CPS Technical Conference in Calgary earlier this year.

Abstract - Interest in complete overcurrent device selectivity has increased due to the addition of selectivity requirements to articles 700, 701, and 708 of the National Electrical Code (NFPA70). Many users, both commercial and industrial, use fuses and circuit breakers simultaneously. Traditional Time-Current Curve (TCC) analysis is known to not fully communicate fuse selectivity; hence fuse manufacturers publish device ratio guidelines for selection of fuse type and sizes. Recent publications of selectivity tables by circuit manufacturers also demonstrate that traditional TCCs are often insufficient to fully communicate circuit breaker selectivity. Traditional TCCs can lead to incorrect conclusions regarding circuit breaker fuse selectivity, indicating more or less selectivity than may be possible. The authors will describe various methods for assessment of selectivity in systems using both fuses and circuit breakers together, with either device on the line side. The methods will demonstrate that selectivity above what TCCs demonstrate may be possible if devices are selected correctly, and that traditional TCC analysis, can also incorrectly demonstrate more selectivity than a more thorough analysis would predict. The methods lend themselves to analysis that a power system engineer can perform with published information or information that may be requested from manufacturers.

To read the paper in its entirety, visit: us.ferrazshawmut.com/resources/media/articles/IEEE-Selectivity-Analysis-White-Paper.pdf.

About Ferraz Shawmut

Ferraz Shawmut has been a leader in circuit protection for industry and the electrical market for more than 100 years. With a complete line of current-limiting fuses and accessories, Ferraz Shawmut prides itself on delivering innovative, problem-solving products like the Surge-Trap® SPD, Thermally Protected Metal Oxide Varistor (TPMOV®), the FSLBS Load Break Switch, the SmartSpot® open-fuse indicator, Amp-Trap 2000® fuses, and UltraSafe(TM) fuse holders. Two of the company's latest innovations are its new line of Amp-Trap® High-Speed Class J (HSJ) fuses, engineered specifically for the protection of today's sensitive electronic motor controllers, and the industry's first line of Finger-Safe Power Distribution Blocks (FSPDBs), delivering the ultimate in safety and ease-of-use when making power connections in electrical panels. Ferraz Shawmut, LLC. is a subsidiary of the Carbone Lorraine Groupe. For more information, contact the company by phone at (978) 462-6662 or visit us.ferrazshawmut.com.

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Newburyport, MA 01950

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