1.Good product Construction and Thermal Management
A good high mast LED flood light fixture generally consists of a housing and electrical (driver) compartment typically made from low copper die cast aluminum. The heavy duty aluminum flood housing is designed to accommodate all electrical and optical components. A metal core printed circuit board (MCPCB) provides the thermal connection between heat sink and LED package, electrical insulation and the transfer of electricity into the LEDs. A lens frame fixes a clear or prismatic lens made of tempered glass or impact resistant polycarbonate. The frame is then mechanically sealed with a silicone gasket for weather tight operation. One challenge in designing high mast led flood light fixtures is that the high power LEDs emit a high amount of heat. Hence, it may be advantageous to remove the heat generated by the LED from the LED semiconductor junction and maintain the internal temperature of the luminaire assembly below the maximum operating temperature so the electrical and electronic components therein maintain performance. Thermal management, therefore, has become increasingly important in high mast led flood light. LED floodlights feature cast aluminum heat sink behind the LED assembly to control heat buildup and dissipate heat. Heat sinks are thermal conduction pathways that is integrated into a lighting system to remove or redistribute thermal energy from LEDs through thermal conduction with these heat sources. The aerodynamic vents created by the heat sink fins generate efficient air flow and accelerate natural convection. Hot air converges smoothly into a fast laminar flow, quickly transferring heat to the ambient environment. Other thermal management strategies have utilized heat pipes that combines the principles of both thermal conductivity and phase transition heat transfer mechanism. The complete separation of the electrical compartment from the LED assembly keeps the driver and other control circuitry very cool, effectively maintaining the driver's service life in high ambient operating temperatures. The housing is pre-treated and powder-coated to resists extreme weather conditions without cracking or peeling and provide optimal color and gloss retention. The led flood light design is increasingly incorporating more aesthetic elements. The attractively styled contemporary design with smooth curves and contoured edges blend unobtrusively with the environment.
2.LED Chips
The selection of high mast led flood light arrays, modules, or field replaceable LED light engines depends on various design considerations, such as light quality, light output, operating temperature, luminous efficacy, LED drive current, and maintenance, etc. In general, high power LEDs are designed with low thermal resistance, high efficiency, high brightness, high reliability, and superior corrosion robustness. The transition from low- and mid-power LEDs to high-power devices has challenged the LED packaging industry to seek efficient thermal designs that function at higher forward currents and temperatures. Top LED brands such as OSRAM OSLON Square, CREE XLamp LEDs, Lumileds LUXEON Rebel LEDs, and Nichia high power LEDs have very mature designs for a wide range of industrial and outdoor applications where high light output, excellent optical characteristics and maximum efficacy are required. It's of extreme importance to minimize the thermal resistance from the solder point to ambient for efficient heat dissipation in order to optimize luminaire life, lumen maintenance and optical performance even in the highest ambient environment.
3.LED Driver
LED drivers designed to operate the LEDs under wide temperature and electrical ranges to ensure reliability for the most rugged applications. The driver is designed to accept a universal input voltage e.g. 90-305V AC or 120-277V AC. System power factor is generally greater than 0.9 at full load. The total harmonic distortion, or THD, is required to not exceed 20% (a THD of less than 10% is exceptionally good). The driver is thermally protected from excessive temperature. The output overvoltage and overcurrent circuit provides protection against transient peak currents, transient voltage spikes and drops that can occur in electrical systems which would otherwise lead to burning up or premature LED failure without it. The driver components are encased in a IP66/67 water proof, flame resistant plastic enclosure.
4.Beam Patterns
Each floodlight fixture designer to satisfy the demands of the client and meet the parameters of different optical solutions. The primary optic is included in the LED package, and the secondary optics are part of the floodlight fixture and are designed to shape the radiation pattern, or beam pattern, maximize efficiency and application spacing. Secondary optics provide unique optical combination possibilities to modify the LED output beam such that the output beam of the floodlights efficiently meets the desired photometric specification. LED secondary optics include reflectors, lenses, total internal reflection (TIR) lenses, and diffusers. Lens has the excellent light-gathering ability to control the distribution of light rays at a small angle. While the reflector has the advantage to redirecting the flux (illuminance) and converging the rays at a large angle. A TIR lens is a combination of lens and reflector, using the principle of total reflection optics to collect and process light. For high voltage applications it is recommended to use PMMA (acrylic) or PC (polycarbonate) lens for their high mechanical strength, excellent optical properties, good thermal stability, high thermal conductivity, and low moisture and water absorbing capacity. In high power floodlighting, lenses and TIR lenses are often used for better uniformity and higher optical efficiency (at least 90% for most applications). It makes sense, however, to use a reflector design in some applications, e.g. sports lighting, to achieve a designed beam pattern and minimize spill light and glare.
5.Lighting Control
The implementation of controls in high mast led flood light offers many benefits such as energy savings, reduction in light pollution, extending the luminaire life and compliance with energy codes. LED drivers are generally equipped with to dimming circuit for 0/1-10V dimming, DALI digital dimming, or PWM dimming, to allow for adjustment of lighting levels. LED flood lights may also be controlled by motion sensors and are configured to illuminate from low to high power or turn on/on when motion is detected. A photocell can be installed to provide dusk-to-dawn illumination. Emery management system or addressable intelligent controls offers the greatest flexibility and provide multi-way communication channels for networked control. LED RGBW architectural flood lights, for example, can be operated under DMX512 consoles to create fixed or dynamic colorful lighting effects for flood, wash and accent lighting applications to enhance architectural features.
