BR lamps are an improved version of R lamps in that they deliver light emitted by an incandescent or halogen source more effectively out of a recessed downlight or track luminaire than R lamps. When an R lamp is recessed deeply into a cylindrical luminaire, light at the edge of the beam can strike the inside of the luminaire. The improved version of R lamps has a bulged reflector near the base of the lamp. The extra reflector that has a bulged shape concentrates light at the center of the beam, resulting in less wasted light when the lamp is deeply recessed into luminaires. The BR lamp takes its name from this design. The number symbol in the lamp designation indicates the diameter of the bulb in eighths of an inch. A BR40 lamp has a nominal diameter of 50 eighths of an inch, or 5 inches. A BR30 lamp has a nominal diameter of 30 eighths of an inch, or 3.75 inches. A BR20 lamp has a nominal diameter of 20 eighths of an inch, or 2.5 inches. The BR20 bulbs is often referred to as R20 but it shares the same characteristics of other BR bulb types. BR lamps are commonly fitted to an E26 medium screw base.
at the Open Lighting Product Directory (OLPD)
