Some things, as the saying goes, need an “act of Congress” to get done. Widespread adoption of more efficient electric motors? Perhaps. Regardless, federal legislation passed three years ago seeks to hasten the shift by mandating that manufacturers selling into the U.S. market build many new motors to higher efficiency standards come December.

The Energy Independence and Security Act of 2007 (EISA) requires general-purpose “Subtype I” motors in the 1-hp to 200-hp category — and manufactured alone or as a component of another piece of equipment — be built to minimum nominal full-load efficiency standards as defined in NEMA MG-1 (2006) Table 12-12.

Those standards generally define the premium-efficient motor — ones that may carry the NEMA Premium designation. That category came into being with passage of the Energy Policy Act of 2005, which required motors procured for federal uses to meet those higher efficiency ratings.

EISA effectively expands those federal procurement guidelines to many motors used in commercial and industrial applications. It succeeds efficiency standards that were mandated for such motors in the Energy Policy Act of 1992 (EPAct ’92). The new EISA standards are several percentage points higher than efficiency ratings that define those so-called EPAct motors, and which are spelled out in NEMA MG-1 (2006) Table 12-11.

EISA also raises the efficiency bar for various other types of motors. Some that had been exempted from EPAct ’92 standards, which were one to four percentage points higher than efficiency ratings for standard-efficiency motors, will now have to meet EPAct ’92 efficiency guidelines. Such motors, called Subtype II, incorporate Subtype 1 design elements but have non-standard configurations.

EISA also brings NEMA Design B motors sized between 200 hp and 500 hp under the EPAct ’92 efficiency prescriptions, as well as fire-pump motors.