On Mar 9, 2010, the US Department of Energy (DOE) did publish its Final Rule giving efficiency limits that must be met by "small" general-purpose electric motors, starting in 2015. As the Energy Policy Act and its requirements became common knowledge, everyone was aware that it concerned "integral horsepower" motors of 1-200 horsepower (hp) only. "Small" motors rated under 1 hp were outside the law's coverage. As part of the process of comparing existing efficiencies with what might be possible, the DOE undertook its own testing program, for three representative 4-pole ratings: three-phase 1 hp 56 frame (six motors), CSIR 1/2 hp 48 frame; and CSCR 3/4 hp 56 frame (one motor each). As reported in its "Engineering Analysis", the tested motors were then torn down for component study. However efficiency may be measured, defining it has been one of the DOE's major concerns.