Guide to High Mast Lighting
Outdoor areas with a lot of activity like airports, shipping ports, highways, merging expressways, transportation terminals, and sports fields usually need high mast lighting because they require extra safety and security. High mast lighting is very cost-effective and is the best way to illuminate large outdoor spaces that need high-quality light.
What Is High Mast Lighting?
High-mast lighting is a tall pole with lighting attached to the top pointing towards the ground, usually but not always used to light a highway or recreational field. It is used at sites requiring lighting over a large area. The pole that the lighting is mounted on is generally at least 30 meters (100 feet) tall (under this height it is referred to as conventional lighting system), while the lighting consists of a luminaire ring surrounding the pole with one or several independent lighting fixtures mounted around it. Most units have four, six or eight lights in the ring, with ten, twelve and sixteen lights used in rarer instances. While most high-mast lights are high-pressure sodium, other types such as mercury vapor, metal halide and LED, have also been used. Some units have the lighting surrounded by a circular shield to prevent or reduce light pollution or light trespass from affecting neighbourhoods adjacent to the highway. 
Maintenance of these systems are done by lowering the luminaire ring from the mast head to the base using a winch and motor to the ground or at a height accessible by a cherry picker and located in areas to allow for easier access without disrupting traffic.
Think of Light Maintenance
One of the biggest downsides of HID mast lights is that they need a lot of maintenance. The lights have a lifespan of 15,000-25,000 hours, which means electricians must replace them frequently – a procedure that can be labor-intensive and time-consuming, considering how high the lights usually are. In most instances, when HID lights are being replaced the ballasts must also be replaced, which adds to the overall maintenance costs.
HIDs also have a very high rate of lumen depreciation and lose most of their lumens before they get to the end of their lifespans. In fact, by the time they reach half of their lifetimes, they may have lost half of their lumens. Their degradation process is also not a straightforward one as they start to shift colors as they reach the end of their lifespans. Electricians usually have to change out the bulbs as soon as their efficiency decreases as most outdoor areas with high mast lights need maximum illumination.
LEDs have long lifespans (50,000 to 100,000 hours), maintain 70% of their lumens for their entire lifetimes, do not use ballasts, and don’t shift colors as they age. The lights are basically maintenance-free, the only maintenance that may have to be done is dusting the fixtures.
The primary appeal of LED street lighting is energy efficiency compared to conventional street lighting fixture technologies such as high pressure sodium (HPS) and metal halide (MH). Research continues to improve the efficiency of newer models of LED street lights.
An LED street light based on a 901-milliwatt output LED can normally produce the same amount of (or higher) luminance as a traditional light, but requires only half of the power consumption. LED lighting does not typically fail, but instead decreases in output until it needs to be replaced. It is estimated that installation of energy efficient street lighting in the 10 largest metropolitan areas in the U.S. could reduce annual carbon dioxide emissions by 1.2 million metric tons, the equivalent of taking 212,000 vehicles off the road, and save at least $90 million annually in electricity costs.
As LED lighting fixtures normally produce less illumination it is important to use a well-distributed illumination pattern in order to produce the same illumination as higher-lumen conventional fixtures. For example, different LEDs in one fixture can target different points on the street.
Advantages of LED high mast lights
- Low energy consumption: Many LED lighting retrofits have been claimed to dramatically reduce energy use.
- Long and predictable lifetime: The projected lifetime of LED street lights is usually 10 to 15 years, two to four times the life of currently prevalent HPS. (LEDs themselves do not generally fail or “burn out” in a way comparable to other technologies, and barring catastrophic failure of other mechanical or electronic components of the LED fixture, lifetimes are typically set by a decrease in luminous output of 30%. But the functional lifetime of an LED fixture is limited by the weakest link; associated drive electronics are typically projected to last about 50,000 hrs. It is important to understand that no LED streetlighting products have been in service long enough to confirm the projections). If realized in practice, the less frequent need to service or replace LEDs will mean lower maintenance cost.
- More accurate color rendering: The color rendering index is the ability of a light source to correctly reproduce the colors of the objects in comparison to an ideal light source. Improved color rendering makes it easier for drivers to recognize objects.
- Quick turn on and off: Unlike fluorescent and high-intensity discharge (HID) lamps, such as mercury vapor, metal halide, and sodium vapor lamps, which take time to heat up once switched on, LEDs come on with full brightness instantly.
- Immediate restart: Unlike mercury vapor, metal halide and sodium vapor lamps (commonly used in street lighting), LEDs do not have a problem restarting immediately (hot ignition) following a brief power failure or inadvertent turn off.
- RoHS compliance: LEDs don’t contain mercury or lead, and don’t release poisonous gases if damaged.
- Less attractive to nocturnal insects: Nocturnal insects are attracted to ultraviolet light emitted by many conventional light sources.
- Optically efficient lighting equipment: Other types of street lights use a reflector to capture the light emitted upwards from the lamp. Even under the best of conditions, the reflector absorbs some of the light. Also for fluorescent lamps and other lamps with phosphor coated bulbs, the bulb itself absorbs some of the light directed back down by the reflector. The glass cover, called a refractor, helps project the light down on the street in a desired pattern but some light is wasted by being directed up to the sky (light pollution). LED lamp assemblies (panels) can send light in the desired directions without a reflector.
- Reduced glare: Directing the light downward onto the roadway reduces the amount of light that is directed into driver’s eyes.
- Higher light output even at low temperatures: While fluorescent lights are comparably energy efficient, on average they tend to have lesser light output at winter temperatures.
Cut Costs by Switching to LED
If you own or manage an area with high mast lights, you should seriously consider upgrading to LED. LED bulbs can be easily installed on the existing fixtures and instantly reduce energy consumption. They will also offer many other benefits and help you to get back the money you invested in a short period of time.
The great thing about LEDs is that you can spread their weight evenly on a mast and their lenses will focus the light exactly where it needs to go. However, conventional luminaries may have to be placed on one side of a mast to illuminate a specific area – which may create an unequal load.
YOULUMI has a variety of LED HighMast Lighting Solutions that are suitable for different types of high masts. We also offer different combinations based on the lighting requirements of your outdoor space.
Post time: Nov-19-2018