Fluorescent ballasts are the “engine” of the lighting systems, and are designed to provide the proper electrical voltage to begin the lighting sequence, to regulate the electrical current flowing through the lamp to stabilize the light output, and to supply the correct voltage required for proper lamp operation. “Fluorescent ballasts must compensate for voltage level variations to ensure the lamp stays lit, even if the voltage fluctuates,” explained Dave Levinson, vice president of marketing for Advance Transformer Co., Rosemont, Ill.

For more than 50 years, electromagnetic ballasts were used to power fluorescent lamps. The improvements of electronic circuits and components, however, have led to the development of electronic ballasts. According to Universal Lighting Technologies, Nashville, Tenn., electronic ballasts are the first choice of specifiers today because they are better able to meet the ever-changing and growing needs of fluorescent lighting applications in the commercial, industrial and residential markets.

Combined industry magnetic and electronic ballast sales are estimated to be more than $1 billion, with a billion magnetic units and half a billion electronic units currently installed and operating in commercial and industrial applications.

“Through market evolution and upcoming federal and state legislation designed to reduce national energy consumption through mandated product efficiency standards, the electronic ballast market is poised to grow at 10 to 20 percent annual rates as electronics increasingly replace magnetic ballasts in appropriate market applications,” said Levinson of Advance Transformer.

In response to regulatory and energy issues, the controllable, or dimmable ballast market has also been gaining momentum recently, according to Paul Trively, vice president of specification sales at Lutron Electronics Inc., Coopersburg, Pa. “Over the next 10 years, dimmable ballasts may represent 50 percent of all new installations, as compared to the 2 to 5 percent share today,” he said.

Changes in technology

As lamp companies create more varied choices of linear fluorescents and compact fluorescent lamps (CFLs), ballasts have been developed that enable these products to be dimmed to levels as low as 1 percent of light output, making them a cost-effective alternative to incandescent downlights. “CFLs need about one-third the amount of energy as incandescent lighting to produce the same light levels and can now be used in spaces that require dimming controls,” said Trively. The newer higher wattage CFLs, which are used with electronic ballasts, can produce up to 120W/9000Lm, which is roughly equivalent to a 175W HID light source.

According to Tom Bosworth, fluorescent product manager for Advance Transformer, manufacturers are also producing smaller, lower-profile electronic ballast systems that offer a variety of benefits, including increased energy efficiency, higher light output levels, and enhanced versatility, enabling the operation of a variety of lamps from a single ballast. Greg Bennorth, director of specification sales at Universal Lighting, observes that low-profile electronic ballasts are also being developed to provide fixture manufacturers with more flexibility in their products’ design. For example, fixtures are being designed for improved optical efficiency around T8 lamps, while reducing the depth of the fixture to allow easier installation in ceilings.

Reduced energy consumption is one of the biggest factors driving changes in ballast technology. According to Universal, if the operation cycle of a light is less than three hours, programmed rapid-start electronic ballasts can provide up to 50 percent longer lamp life, due to the “softer” starting of the lamp filaments. The ballast, as explained by Mark Timbario, Universal’s product manager for electronic ballasts, is “programmed” to first heat the fluorescent lamp filaments to a proper temperature, and then supply a high voltage to ignite the lamp. As a result, the programmed rapid-starting method and technology extends lamp life over instant-start systems in applications where the lamp is frequently turned off and on.

Finally, the concept of daylight harvesting is changing the landscape of ballast systems. “Customer demand is being driven by the desire to both save electricity and to have ‘green’ buildings,” said Trively. Daylight harvesting systems use sensors to automatically dim a space’s light levels in proportion to the levels of natural light, while still maintaining the desired light levels programmed into the systems by the user of that space.

What’s on the horizon?

Lighting systems are increasingly being integrated with the rest of a building’s automated and energy management systems, and ballasts are a vital part of allowing the user of the space to control and adjust lighting levels to create an optimal environment for increased productivity and satisfaction. “System integration makes it easier for building managers to program the lighting to produce levels in accordance with the time of day and with the activities being performed,” said Trively. For example, electronically controlled ballasts enable security personnel to remotely control lighting, and integrated lighting systems can also be used with the building’s key-card access system to provide pathway lighting to each employee’s individual space. In addition, a building manager who can remotely access the facility’s lighting and ballast system can also ascertain the occupancy status as well as the amount of energy being consumed by the system. “A programmable, controllable electronic ballast is the key to providing these levels of flexibility, versatility, and the sharing of data between all of the building’s subsystems,” Trively added.

Using dimming system and programmable control technology to manage fluorescent lighting systems is going to continue to gain momentum as customers look for new ways to control energy costs, predicts Bosworth. “Two fluorescent T8 lamps at full output consume 68 watts of energy. When that light level is reduced through dimming controls, energy consumption is greatly reduced,” he said.

Low-wattage metal halide high-intensity discharge lamps that consume 150W or less is another technology that is increasingly being used, particularly in ceramic lamps in retail applications, according to John Cummings, senior project manager of HID at Advance. “Electronic ballasts have been developed for HID light sources and in the future will be used more and more in those lighting applications,” Cummings predicted. HIDs are mostly used today in the industrial market and the 5 percent growth rates they have historically experienced are directly tied to the economic fluctuations of that segment.

Also on the horizon is the increased use of the relatively new digital addressable lighting interface (DALI) technology. DALI uses digital signals to control a single, group or whole series of lights in a facility and has been used in Europe for the past five to 10 years. The difference between DALI and analog technology is that the ballasts, which are connected through a computer network, can be individually addressed and configured. The acceptance of the technology in the United States is being driven by the desire of employees and building owners to control the lighting in individual workspaces. DALI also makes it easier to rezone a lighting system in an office or other commercial application without having the expense and trouble of completely rewiring it. At this time, however, DALI systems are limited to 64 addresses. EC

BREMER, a freelance writer based in Solomons, Md., contributes frequently to ELECTRICAL CONTRACTOR. She can be reached at 410.394.6966 or darbremer@comcast.net.