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Safety Evaluation of Nonmetallic Cable Damaged During Installation
Track(s): Electrical, Research

Paul Brazis, Jr., and Fan He, Underwriters Laboratories, Inc.

Audio Sample:




Nonmetallic (NM) cable is the most common electrical wiring method used in residential construction, and is expected to be in service for many decades buried inside walls, floors, and ceilings. Learn about the lack of understanding that currently exists about the specific mechanisms and probability of latent electrical arcing and/or fire if cabling is damaged during installation. Such damage may include over-stapling, excessive bending, crushing, and abrasion. This abuse may be exacerbated by aging of the wire, with problems appearing only years after damage had occurred. UL has initiated a study into the effect of NM cable damage and subsequent mechanical, chemical, and/or electrical degradation over time. This session will focus on a statistical discussion of the initial effects of various damage scenarios to NM cable during installation.

Paul Brazis is a Research Manager with Corporate Research at Underwriters Laboratories (Northbrook, IL). He has a background in electrical and thermal characterization, electronic materials, and device physics, receiving his BS, MS, and PhD in Electrical Engineering, all from Northwestern University. Paul joined UL in 2008 and leads the Electrical Hazards research. His research activities focus in various aspects of electrical safety, including arc fault phenomena, component degradation and ignition, harmonics, and photovoltaic safety.

Dr. Fan He is a Research Engineer with Underwriters Laboratories (Northbrook, IL). He has a BS in Physics from Northeastern University, (Shenyang, China) and a Ph.D. in Physics from the University of Cincinnati. His current research focuses in electrical safety, including investigations into arc ignition phenomena and latent degradation of wiring and insulation materials. Prior to joining UL, Dr. He was a Distinguished Member of the Technical Staff at Motorola, Inc. (Libertyville, IL).