- Author
- Fulcomer, P. M.
- Title
- Temperature Measurement on Operating Surface Mounted Lighting Fixtures.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Sponsor
- Consumer Product Safety Commission
- Report
- NBSIR 79-1912, September 1979, 22 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. Website: http://www.ntis.gov
- Keywords
- thermal insulation | thermocouples | lamps
- Abstract
- Potentially hazardous temperatures may result from adding thermal insulation in the attic above surface mounted incandescent lighting fixtures and/or operating these fixtures with lamps of higher wattage than specified. This study was concerned with the range of temperatures generated (1) within the fixture, (2) within the electric junction box associated with the fixture and (3) on the adjoining ciling and attic surfaces. Test results indicate that the addition of minimal insulation (equivalent to R11) over a surface mounted lighting fixture which contains two or more rated lamps is likely to cause normal household branch circuit supply wiring associated with the fixture to operate above its specified 60 deg. C temperature rating. Overlamping (using lamps of higher wattage that specified for the fixture) and/or additional load current flowing through the branch circuit wire will cause even higher supply wire temperatures. With all three conditions present (i.e., insulation over the fixture, overlamping, and an additional 15 ampere load current flowing through the supply wire), the tests indicate that the temperature of associated branch circuit wiring will exceed 80 deg. C for a one lamp fixture and 100 deg. C for fixtures with two or more lamps.