SIDEBAR No. 2: Controls Compatibility
Lighting controls in the home — from dimmers and vacancy sensors for a single room to sophisticated whole-house control systems — can add energy savings while enhancing lifestyle, according to Craig DiLouie, education director for the Lighting Controls Association, which, administered by the National Electrical Manufacturers Association (NEMA), is dedicated to educating the professional building design, construction, and management communities about the benefits and operation of automatic switching and dimming controls. Dimmers, for example, have been demonstrated to generate an average 20% energy savings. Dimming — with the ultimate option being preset scene control with multiple layers of lighting — can be used to achieve a variety of scenes and moods with the push of a button. The Department of Energy estimates that 12% of all lamps in residences are controlled by a dimmer.
Under the new lamp standards, the safest bet for consumers is to replace incandescent lamps with energy-saving halogen lamps, says DiLouie, as these products dim reliably on the same control devices. If choosing compact fluorescent lamps (CFLs) or LED lamps to fill a socket controlled by a line-voltage, forward-phase control (typical incandescent) dimmer, consumers need to be aware of potential compatibility issues.
“Consumers are accustomed to matching an incandescent lamp with a dimmer and having clear expectations and then have those expectations met,” says DiLouie. “With new lamps, careful selection is required.”
First, the lamp must be designed and rated as dimmable; consumers should never try to dim a non-dimmable lamp on a dimming circuit, or risk damaging components. Second, consumers should be aware of how the technology behaves while dimmed — for example, typically, CFLs visually get a little cooler (bluer) at low dim levels, while incandescent lamps become visually even warmer (red-orangish) — so they have clear expectations on what they are going to get. Third, some compact fluorescent and LED lamps may exhibit poor performance such as flicker on incandescent dimmers, or suffer damage if there is incompatibility.
To support compatibility between selected lamps and dimmers, NEMA recently introduced two major standards. The first, LSD-56-2011, defines compatibility between compact fluorescent lamps and forward phase-control dimmers commonly used to dim incandescent lamps. The dimmer must provide a certain waveform, and the lamp must accept it. The dimmer must provide a minimum voltage at the lowest dim setting, while the lamp must operate at that setting without any major visual instabilities, such as flicker. If the dimmer uses a microprocessor requiring a small amount of current during the OFF state, the lamp must be able to shunt it without flashing.
The second standard, SSL-2010, was produced by NEMA to address compatibility between dimmers and integrated LED replacement lamps. The requirements address dimming of these lamps and the interaction between the dimmer and the lamp, ensuring good dimming performance and preventing damage to either component.