Product Selection Guide Page 1105 Product Selection Guide-11th Edition

1105 PRODUCT INFORMATION Luminaire Classification System LUMINAIRE CLASSIFICATION SYSTEM PSG11 TECHNICAL INFORMATION CUTOFF CLASSIFICATIONS CLASSIFICATION DEFINITION BENEFITS LIMITATIONS Full Cutoff Zero intensity at or above horizontal (90 above nadir) and limited to a value not exceeding 10% of lamp lumens at or above 80. Limits spill light onto adjacent property, reduces glare. No light is emitted directly from the luminaire into the sky. May reduce pole spacing to maintain uniformity and increase pole and luminaire quantities. Cutoff Intensity at or above 90 (horizontal) no more than 2.5% of lamp lumens, and no more than 10% of lamp lumens at or above 80. Small increase in high-angle light allows increased pole spacing. May allow some uplight from luminaire. Typically a small overall impact on sky glow. Semi-cutoff Intensity at or above 90 (horizontal) no more than 5% of lamp lumens and no more than 20% at or above 80 High-angle light accents taller vertical surfaces such as build- ings. Most light is still directed downward. Little control of light at property line. Potential for increased glare when using high wattage luminaires. Typically directs more light into the sky than cutoff. Non-cutoff No limitations on light distribution at any angle. Uniform luminous surfaces such as internally illuminated signs or globes. Wattage should be limited. Suitable for sports lighting, facade, landscape or other applications where luminaires are tilted due to limitations in pole or fixture locations. Location and aiming are critical. Most likely of all categories to produce offensive brightness and sky glow. Luminaire Classification System (Continued) The forward and backlight zones near or slightly below horizontal provide a useful analysis of high angle brightness, often relating to objectionable glare. Keep in mind however, that glare relates to other factors including the size of the source and specific intensity at discrete angles. So additional research will continue to evaluate how to best quantify glare. Evaluation of backlight must consider where the pole is located in relation to the property line. And finally, in considering sky glow impact, the light at or near horizontal has a greater impact on the scattering of light in the atmosphere - resulting in a higher degree of sky glow over a community. BUG Ratings In February 2009, the TM-15 standard added zonal lumen limits defining Backlight (B), Uplight (U) and Glare (G) ratings. The zonal lumens in specific solid angles define a rating from 1 to 5 for each of three categories, with 1 being the most restrictive. IES TM-15-11 was amended with Addendum A, which tightened the values for the U2 ratings from 100 to 50 for BH and UL, and the G1 and G2 ratings for FVH and BVH from 250 to 100 and from 375 to 225 respectively. You will also notice there are two different BH glare ratings. The zonal lumen thresholds are different for luminaires that have a symmetric distribution such as a Type V or Type V square from those that have a longitudinal or forward throw type of distribution such as Type I, II, III or IV. BUG ratings for our products are available using the Acuity online Photometric Viewer. BACKLIGHT/TRESPASS SECONDARY SOLID ANGLE B0 B1 B2 B3 B4 B5 BH 110 500 1000 2500 5000 >5000 BM 220 1000 2500 5000 8500 >8500 BL 110 500 1000 2500 5000 >5000 UPLIGHT/SKYGLOW SECONDARY SOLID ANGLE U0 U1 U2 U3 U4 U5 UH 0 10 50 500 1000 >1000 UL 0 10 50 500 1000 >1000 GLARE SECONDARY SOLID ANGLE G0 G1 G2 G3 G4 G5 GLARE FOR TYPES I, II, III, IV, V and V SQUARE FVH 10 100 225 500 750 >750 BVH 10 100 225 500 750 >750 FH 660 1800 5000 7500 12000 >12000 GLARE FOR TYPES I, II, III AND IV BH 110 500 1000 2500 5000 >5000 GLARE FOR TYPES V AND V SQUARE BH 660 1800 5000 7500 12000 >12000 Though the IESNA discontinued the use of the Cutoffclassifications and associated terminology, it remains in effect in many municipalities, engineering specifications, and even product literature. Though no longer an industry-supported classification, we have included it here for use as reference material only.

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