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What's Wrong Here?

Jun 1, 2003 12:00 PM, By Joe Tedesco, NEC Columnist

Hint: This surface-mounted luminaire contains a ballast that is installed directly on combustible low-density cellulose fiberboard.

Ray Keith, project sales and engineering, Electric Motor Shop, Inc., Fresno, Calif., sent in the following correct response.

“This installation is clearly in violation of 410.76(B), which doesn't allow for direct mounting of a lighting fixture to this surface. There should be no less than 1.5 in. clearance from the surface of the fiberboard ceiling to the fixture housing.”

Joe adds this reference, which is taken directly from the 2002 Code.

“410.76(B) Combustible Low-Density Cellulose Fiberboard. Where a surface-mounted luminaire (fixture) containing a ballast is to be installed on combustible low-density cellulose fiberboard, it shall be listed for this condition or shall be spaced not less than 38 mm (1.5 in.) from the surface of the fiberboard.

“FPN: Combustible low-density cellulose fiberboard includes sheets, panels, and tiles that have a density of 320 kg/m³ (20 lb/ft³) or less and that are formed of bonded plant fiber material but does not include solid or laminated wood or fiberboard that has a density in excess of 320 kg/m³ (20 lb/ft³) or is a material that has been integrally treated with fire-retarding chemicals to the degree that the flame spread in any plane of the material will not exceed 25, determined in accordance with tests for surface burning characteristics of building materials. See ANSI/ASTM E84-1997, Test Method for Surface Burning Characteristics of Building Materials.”