- Author
- Faison, T. K.
- Title
- Field Measurement of Branch Circuit Wire Temperature.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Sponsor
- Department of Energy, Washington, DC
- Report
- NBSIR 81-2347, November 1981, 44 p.
- Distribution
- AVAILABLE FROM National Technical Information Service (NTIS), Technology Administration, U.S. Department of Commerce, Springfield, VA 22161. Telephone: 1-800-553-6847 or 703-605-6000; Fax: 703-605-6900; Rush Service (Telephone Orders Only) 800-553-6847; Website: http://www.ntis.gov
- Keywords
- electric wire | thermal insulation
- Abstract
- The National Bureau of Standards (NBS), under the sponsorship of the U.S. Department of Energy (DoE), planned and conducted a program to monitor temperature excursions of residential branch circuit wiring under field conditions. The program was conducted to develop a field data base needed to determine the prevailing conditions in the field and to respond to various assertions that the encapsultion of branch circuit wiring within thermal insulation is a potential hazard. It has been demonstrated through previous laboratory invetigations that buried wires, when operated continuously at rated ampacity, will exceed the thermal limit established by the National Electrical Code (NEC). Approximately 2,800 circuits in 667 residences were monitored through a volunteer program with the utilities. The results of the study show that slightly more than one-third of the circuits monitored operated at or above the thermal limit established by the NEC, 60 deg. C (140 deg. F). Thermal distributions are shown for variables such as: region, season, and age.