Development and Analysis of Electrical Receptacle Fires

• NCJ Number: 243828
• Author(s): Matthew E. Benfer; Daniel T. Gottuk
• Date Published: August 2013
• Length: 346 pages
• Grant Number(s): 2010-DN-BX-K218
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical); Report (Study/Research); Report (Grant Sponsored)
• Award: Electrical Fires' Forensic Signatures of Fire Cause Events

Annotation

Laboratory testing of the impact of a wide range of variables on the formation of over-heating connections in residential duplex electrical receptacles focused on terminal connections and plug connections.

Abstract

The testing found that only the loosest connections tended to form significant overheated connection irrespective of other variables, such as receptacle materials and installation. Forensic signs of overheating were found to persist even after external fire exposure. In addition, locations of arcing within receptacles due to fire exposures were identified and characterized. The location of arcing was primarily dependent on the duration and intensity of the fire exposure, as well as the construction and materials of the receptacle, outlet box, and faceplate. Characteristic indicators of arcing and melting were identified and analyzed. Study results establish a baseline for post-fire assessment of whether electrical receptacles may have been identified along with techniques for evaluating post-fire evidence in order to differentiate between electrical overheat/receptacle fire signature and damage resulting from an external fire exposure. It is anticipated that the forensic signatures identified in this work will be used in assessing electrical receptacle fires. Implications are drawn for further research. Testing involved 528 receptacle trials, 408 trials with various terminal connections, and 120 trials with various plug connections. Thirteen prefabricated wall assemblies of 36 receptacles were placed in 8 compartment fire tests and 5 furnace fire tests. The variable assessed in the fire exposure testing included the receptacle material, materials of the receptacle faceplate and box, terminal torque, and energized state of the receptacle. Extensive tables and figures, 73 references, and appended summaries of test data