The National Electrical Manufacturers Association recently published NEMA BL 3-2013 Dimming Ballast Energy Performance. This standard provides a methodology for applying existing test methods for program start ballasts to fluorescent dimming ballasts. It also provides a method to calculate ballast luminous efficiency (BLE) for fluorescent dimming ballasts.
Information for proper lamp and ballast compatibility for reliable long term dimming system operation can be found in NEMA LL 9-2011 Dimming of T8 Fluorescent Lighting Systems. Additionally, the Department of Energy (DOE) has developed uniform requirements for programmed start ballasts in the course of ballast rulemaking. BL 3 combines the new 2014 DOE standard for programmed start ballasts with the lamp compatibility aspects of the LL 9 document. The resulting proposal will suggest dimming ballasts be evaluated to BLE performance metrics similar to the programmed start levels, but adjusted to provide for some additional losses due to the added control complexity and also for the heating power lost in the lamp cathodes.
NEMA BL 3-2013 Dimming Ballast Energy Performance may be purchased in electronic or hardcopy format for $32 on the NEMA website here.