On Dec. 19, 2013, the US Department of Energy (DoE) issued a Notice of Proposed Rulemaking covering 1-HP to 500-HP, three-phase induction motors. These recommended changes are based on a study conducted in late 2010. The rule was adopted from a petition filed by the National Electrical Manufacturers Association (NEMA) and a coalition of energy advocates to broaden the scope of coverage while retaining the premium efficiency level and making compliance and enforcement easier.
With the new proposed rule, almost all three-phase motors in three-digit NEMA frames and enclosed 56 frames (plus IEC equivalents) will need to meet premium efficiency levels per NEMA MG 1 Table 12-12. This includes NEMA Designs A, B, and C and IEC Designs N and H. Many designs, such as gear motors, partial motors, vertical, TENV, encapsulated, immersible, and others previously not covered, will also need to comply. The DoE also issued a Final Rule for testing motors that cover these configurations.
A Final Rule on these 1-HP to 500-HP motors is expected in May 2014, with a proposed compliance date of Dec. 19, 2015. The coalition proposal requested two years from Final Rule as the compliance date.
It seems that any buyer of motors, especially those that use a lot of power, would of course consider the efficiency of a motor as a major parameter in making the selection of which motor to select. This is true because in most cases the cost of power to run the motor over it's lifetime is far greater than the initial purchase price. The very rare exception is motors that are very seldom operated, where perhaps reliability and size are more important than efficiency.
So while uniform test procedures would be a worthwhile rule to enforce, as well as truth in advertising and labeling, it wo8uld seem that the market would enforce the production of only the most efficient motors. Of course, there may be something else not mentioned in the discussion, such as a tendancy for some offsore sources to provide completely false information about their products, the most obvious is overstating wire sizes. Finding a spool of wire marked as number 12 and finding that it is actually much closer to what would be number 15 is not a nice surprise.
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