Craig DiLouie of the Lighting Controls Association recently talked to Randy Reid, VP marketing for LUXIM, about the control aspects of this interesting and novel lighting technology.
DiLouie: Are plasma lighting systems dimmable?
Reid: Yes, they can dim to 20% with standard 0-10VDC controls. Dimming is nearly instantaneous, occurring in about a second. Return from dimming to full is also nearly instantaneous. This is ideal for applications where bilevel lighting is required by code, or where we want to reduce lamp power without turning the source off entirely, which could affect safety.
DiLouie: What are typical control strategies enacted with plasma lighting?
Reid: The most popular applications for light-emitting plasma at this time are outdoor parking lot and roadway lighting.
DiLouie: What changes, if any, occur to the quality of light during dimming—as in CRI, CCT, etc.?
Reid: The lamp will shift to the cool portion of the color spectrum. We offer three CRI ratings: 75,80 and 95. The CRIs will Both drop during dimming. In many dimming applications, dimming occurs as a result of occupancy sensing, so the quality of light will not be an issue.
DiLouie: What changes, if any, occur to lighting efficacy during dimming?
Reid: Plasma dimming is not linear; 20% of initial lumens, for example, is 50% of lamp power. This allows users to maintain a minimum light level with bilevel lighting while saving 50% energy.
DiLouie: What control devices are plasma systems compatible with—e.g., occupancy sensors, manual dimmers, digital switches, photosensors, etc.?
Reid: All can be used. The driver features a built-in 0-10VDC input for dimming, direct low-voltage input for occupancy sensors, and a serial interface for digital controls allowing connection with digital protocols. As for switching, the source starts and restrikes fast compared to HID. Additionally, the driver features built-in monitoring capability, logging operating parameters such as temperature, voltage and current.
DiLouie: What effect, if any, does frequency of switching and dimming have on plasma system service life?
Reid: It increases. This is important because it is the opposite of HID. Our lamp is quartz glass and rated to 50,000 hours, when the lamp reaches useful life based on the L70 metric. Because there are no electrodes, there is nothing to break; the quartz glass will simply begin to wear. With dimming, the quartz glass is operated cooler, which will extend the life of the lamp—similar to how dimming increases the life of an incandescent lamp.