The National Electrical Manufacturers Association (NEMA) published a white paper that explains the Fluorescent Ballast Rule and the associated measurement methods, NEMA LSD 66-2017 Understanding the Fluorescent Ballast Rule, EPCA 10 CFR 430.

"This white paper updates a 2012 ballast ruling, which became effective in 2014, and offers historical context for the current use of the ballast luminous efficiency metric," said Ed Thomas, chair of the NEMA Ballast & Driver Section Technical Committee. This revision of LSD 66 contains updated language.

NEMA LSD 66-2017 is available as an electronic download at no cost on the NEMA website.