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Author
Braun, E. | Shields, J. R. | Harris, R. H., Jr.
Title
Flammability Characteristics of Electrical Cables Using the Cone Calorimeter.
Coporate
National Institute of Standards and Technology, Gaithersburg, MD
Sponsor
Department of the Navy, Washington, DC
Report
NISTIR 88-4003, January 1989, 62 p.
Distribution
Available from National Technical Information Service
Keywords
cables | combustion | cone calorimeters | flammability | ignition delay time | heat release rate | gas yield | smoke yield
Abstract
Cone calorimeter tests were performed on eight multi-conductor electrical cables. Measurements of ignition delay time, heat release rate, mass loss rate, and gas and smoke generation rates were made in the vertical (2 irradiance levels) and horizontal (3 irradiance levels) orientations. It was found that comparable ignition delay times were observed for all of the cross-linked polyolefin jacketed cables. The PVC jacketed cable had a substantially lower ignition delay time. All of the cables exhibited an ignition delay time dependence on external irradiance approximately proportional. Sample orientation did not significantly effect the ignition delay time. Heat release rate measurements showed that the cables burned in multiple stages. Each stage of burning was associated with the decomposition of a layer of the cable assembly. For some cables at low external irradiances, only the outer jacket of the cable burned. At higher irradiances, the outer jacket burst open exposing the interior cable materials and secondary heat release rate peaks resulted. Changes in the cable components actually burning were reflected in variations in mass loss, gas and smoke generation rates as well as small changes in the effective heat of combustion. HBr and HCl were detected during the burning of some of the cables. The production of HCN was detected at some point during the combustion of most of these cables.