Understanding Metal Halide Lighting
Metal halide lighting is a type of high-intensity discharge (HID) lighting that uses an electric arc to produce light. Known for their high color-rendering index (CRI) and energy efficiency, metal halide lamps are a popular choice for various applications, including parking lots, sports game lighting, and automotive headlamps. The technology behind metal halide lighting involves creating an electric arc between two electrodes within a clear arc tube filled with gas and metal salts. This arc tube, typically made of quartz or ceramic materials, is crucial for the lamp’s operation. To function correctly, metal halide lamps require a ballast, which regulates the current and provides the necessary voltage to start and maintain the arc.
Pulse Start vs. Probe Start Metal Halide Lighting
High-intensity discharge (HID) metal halide (MH) lamps are widely used in commercial lighting applications because they are about three times as efficient as incandescent lamps. For years, there has been one main technology for middle-wattage metal halide fixtures/lamps: Probe start.
While low-wattage MH fixtures/lamps were pulse start, that technology was not available in the mid-wattage range between 250w and 400w. Today, there is an alternative: A pulse start metal halide (PSMH) fixture and lamp combination that saves energy, increases the life of the lamps, has quicker starts, and lowers operating costs, too! While initially, the fixture and lamp may cost slightly more, the payback is rapid and continues for years. Pulse start and probe start lamps use different ballast systems. Traditional probe start metal halide lamps do not use igniters and require three electrical contacts to ignite the gas and remain lit, which is characteristic of the probe start system. Newer pulse start metal halide lamps use only two contacts and use an igniter located inside the ballast pod, which is a feature of pulse start mh technology.
Ballast Options
When it comes to metal halide lighting, choosing the right ballast is crucial for optimal performance. There are two main types of ballasts: probe start and pulse start. Probe start ballasts use a starting probe electrode to ignite the gas and keep the lamp lit. In contrast, pulse start ballasts employ a high voltage ignitor to heat up the electrodes more quickly during startup. This difference in ignition methods makes pulse start ballasts more energy-efficient and extends the lamp’s lifespan compared to probe start ballasts. Additionally, electronic ballasts are available, offering improved efficiency and reliability over traditional magnetic ballasts. These electronic ballasts further enhance the performance of metal halide lamps by providing more consistent power and reducing energy consumption.
Lamp Characteristics
Metal halide lamps possess several characteristics that influence their performance and longevity. One critical aspect is the arc tube wall, which can become blackened over time, diminishing the lamp’s efficiency. Pulse start lamps, however, boast a longer lifespan—up to 15,000 hours—and higher efficacy, ranging from 90 to 110 lumens per watt, compared to their probe start counterparts. Another important factor is the burn position of the lamp, as some metal halide lamps are designed to operate only at specific angles. Additionally, the open circuit voltage of the ballast plays a vital role in determining the lamp’s performance. By understanding these characteristics, users can make informed decisions about which type of metal halide lamp and ballast system will best meet their needs.
Benefits of Pulse Start-Metal Halide Lamps
Energy Savings of a Pulse Start 320w vs Probe Start 400w MH Lighting System
The benefits are substantial. Pulse start fixtures/lamps offer several benefits:
- Longer Life – Up to 50% longer life, reducing maintenance and replacement cost
- High Efficacy – As much as 24% more lumens per watt, saving energy and money
- Rapid Restrike Time – Less than half the time to relight when shut down
- Better Color Rendition – Superior and stable color rendering as lamps age
- Less Color Variance – Lamps throughout the area appear to be the same color
- Quick Startup – Full brightness in two to four minutes instead of five to ten minutes
- Superior Lumen Maintenance – About 14% less lumen depreciation means more light
Speak to an Access Fixtures Lighting Specialist about Choosing the right Fixture
Access Fixtures is your factory-direct source for all light fixtures needed to suitably illuminate your property. If you have a lighting question, we will be glad to answer your questions. We want to make sure you get the exact fixture for your needs, your budget, and your goals. We are passionate about lighting and love what we do—we’ll get you an answer. To speak with an Access Fixtures lighting specialist, call (800) 468-9925.