The light distribution for floodlights is classified by beam type in accordance with the National Electrical Manufacturers Association (NEMA) classifications. The NEMA designation determines how wide or narrow the light is projected out of a floodlight. The NEMA beam spread is specified between Type 1 through Type 7, based on the field angle at which 10 percent of the maximum intensity is emitted. NEMA beam spread classifications are widely used by the lighting industry to specify the overall light distribution pattern of outdoor directional luminaires.
Axially symmetrical luminaires which have the same horizontal and vertical beam spreads are classified with one NEMA number (i.e., Type 3). Luminaires with asymmetrical light distributions have separate horizontal and vertical beam designations. These luminaires are classified with two NEMA numbers (i.e., Type 5 x 3 or Type 5H x 3V). The horizontal value is always given first.
| NEMA Type | Beam Spread | Beam Description | Beam Projection Distance |
1 | 10° to 18° | Very Narrow | 240 ft and greater |
2 | > 18° to 29° | Narrow | 200 to 240 ft |
3 | > 29° to 46° | Medium Narrow | 175 to 200 ft |
4 | > 46° to 70° | Medium | 145 to 175 ft |
5 | > 70° to 100° | Medium Wide | 105 to 145 ft |
6 | > 100° to 130° | Wide | 80 to 105 ft |
7 | > 130° and up | Very Wide | Under 80 ft |
Axially symmetrical luminaires which have the same horizontal and vertical beam spreads are classified with one NEMA number (i.e., Type 3). Luminaires with asymmetrical light distributions have separate horizontal and vertical beam designations. These luminaires are classified with two NEMA numbers (i.e., Type 5 x 3 or Type 5H x 3V). The horizontal value is always given first.
Six standard beamspreads
Image courtesy of Hubbell Lighting
Image courtesy of Hubbell Lighting
