High mast LED luminaires are high power lighting systems that usually consume hundreds of watts and produce tens of thousands of lumens. The construction of LED luminaires varies depending on type of light sources used, optics design, driver design, and thermal design. The luminaire comprises essentially an LED assembly, an LED driver, a die cast housing, and oftentimes an additional electrical compartment. The LED assembly comes in either an integrated design in which an LED board is thermally interfaced with the luminaire heat sink and protected by the luminaire housing and optical lenses against dust and moisture, or a modular configuration in which the use of self-contained, waterproof light engines eliminates the need for the whole luminaire to be disassembled when there is a need for a modification or upgrade. The LED assembly typically comes equipped with secondary optics to regulate the distribution of luminous flux at package-level, although there're some products, e.g. LED floodlights, using external reflectors to control beam spread.
The luminaire housing often serves the dual purpose of environmental protection and thermal management for the LEDs. Die cast aluminum construction provides strength and durability as well as thermal conduction and convection. LED luminaires used on high mast installations must be reliable and dependable in the most extreme environmental conditions. The aluminum housing is powder coated with a UV stabilized, high corrosion resistant polyester paint, laboratory tested for superior weatherability, cracking and fade resistance. The optical chamber of the integrated-type luminaire is completely sealed with a one-piece extruded silicone gasket placed between the housing and optical lens. High ingress protection (IP) rating ensures absolute resistance to the intrusion of water, insects and dust. A membrane breather equalizes pressure differentials within sealed enclosure to avoid premature seal failure and thus to preserve the integrity of the enclosure.
