Dear LightingTaxDeduction.org,
Are you aware of any clear definition of “bi-level switching”? Depending on the interpretation, there could be a huge array of different qualifiers.
Do you read the "control and circuiting" part of the bill as the lighting fixture or the entire building wiring system?
Does a fixture with a standard 3 wire cord set, with (2) ballasts, qualify? The provision to bi-level switch is in the fixture, it's not actually being taken advantage of in the wiring.
Does a fixture with 2 ballasts and a 4-wire cord set (2 hot) qualify whether or not it is wired to a bi-level switching circuit?
In a retrofit situation, if sensors are not being used, does the building have to run an additional bi-level switching leg to qualify?
Answer: EPAct 2005 does not provide a lot of information about what bi-level switching is, but it is clear on its application: If the Interim Lighting Rule is used, bi-level switching must be installed in all occupancies except hotel and motel guest rooms, store rooms, restrooms, public lobbies and garages (added by IRS Notice 2008-40). Bi-level switching was included as a way to increase energy savings, as the strategy was estimated to produce 10-15% energy savings.
Bi-level switching is not included in ASHRAE/IESNA 90.1-2001. Some state regulations define bi-level switching in a particular way for their own jurisdictions and you must also comply with state and local energy codes. NEMA defines it as manual or automatic control (or a combination thereof) that provides at least two levels of illumination and power in the space besides OFF. The International Energy Conservation Code (IECC) defines it as a manual control allowing occupants to reduce connected lighting load in a “reasonably uniform illumination pattern by at least 50%.” Recognized methods include 1) controlling all lamps and fixtures (e.g., dimming or light level switching), 2) dual switching alternate rows, fixtures or lamps, 3) switching middle lamp independent of outer lamps (3-lamp fixtures, providing three levels of lighting power), and 4) switching each fixture or each lamp.
You listed a number of options in your letter. As long as the option provides at least two levels of lighting power in a space besides OFF, then it would likely qualify. There is no requirement in EPAct 2005’s language for how it’s wired, or the input, or whether it’s manual or automatic: The only requirement is for the output—that is, that there must be a bi-level switching effect.
Note, by the way, that if any of the prerequisites for the Interim Lighting Rules—such as bi-level switching—are already in place in an existing building, then that makes the job of qualifying for the CBTD easier, but any cost incurred before January 1, 2006 will not count toward earning the CBTD. It depends upon when the asset enters service.
As for the circuiting and controls, EPAct 2005 states that the lighting’s circuiting and controls must comply with ASHRAE/IESNA 90.1-2001 if the Interim Lighting Rule is used. However, NEMA’s interpretation of this is that 90.1’s circuiting and controls requirements do not go into effect unless ASHRAE/IESNA 90.1-2001 itself applies (the project is either new construction or a lighting alteration that triggers the application of ASHRAE/IESNA 90.1-2001).
