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IAEI Magazine | Author: Ed Larsen
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Ed Larsen

Ed Larsen is the manager, Industry Standards for circuit protection for Schneider Electric / Square D. He is responsible for managing company activities relating to product standards for overcurrent protective devices, including circuit breakers. Ed currently serves on NEC Code-Making Panel 11, is a member of the UL 1699 Standards Technical Panel and CSA C232(270) Technical Subcommittee for AFCIs and is chairman of the NEMA Personnel Protection Section (GFCIs). As an IEEE member, he authored a chapter in the Blue Book, the IEEE Recommended Practice for Applying Low-Voltage Circuit Breakers Used in Industrial and Commercial Power Systems and has presented papers on selective coordination and the safe application of arc-flash reduction systems. He has also authored articles in various trade journals. He is a member of several other UL, CSA, CANENA, IEEE and NEMA technical committees, the IAEI, IEEE Standards Association, Standards Engineering Society, and NFPA.


GFCI and AFCI Basics

GFCI and AFCI protection have both become fundamental safety devices in electrical systems. Understanding the basics of ground-fault protection for people, and arc-fault protection for 15- and 20-amp branch circuits in dwelling units can ensure that your installations are code-compliant and help you in troubleshooting a circuit. As of the time this article was written (late January 2012), the NFPA code-making panels have met to consider proposals for the 2014 NEC.

New 2011 NEC Requirement Regarding Noninstantaneous Trip Circuit Breakers

There are several requirements in theNational Electrical Code® (NEC®) that call for the total selective coordination of various systems. However, this can result in increasing the downstream arc flash hazard should energized (hot) work be required. Code-making Panel 10 (CMP-10) accepted a proposal for the 2011 NEC in an attempt to address this concern.

Backfeeding Ground-Fault Circuit Breakers

The wording of the exception may introduce confusion as it states that the ground-fault protection device "shall be identified…for backfeeding,” which implies a specific marking on a circuit breaker equipped with GFPE. In actuality it is the absence of "line” and "load” markings on a circuit breaker that indicates that it is suitable for backfeeding.

What Do the Markings on Circuit Breakers Mean?

Have you ever been confused about what the markings on circuit breakers mean? Understanding the markings on electrical equipment is a fundamental need to ensure a safe and reliable electrical installation. Circuit breaker marking requirements are established by the requirements found in the NEC and the UL 489 product standard.