Motor Summit 2010: Comparative standards, regulations
This international forum dedicated to debating and promoting relevant motor system efficiency issues presented a growing program on Oct. 26-28, 2010, in Zurich, Switzerland—following prior successful “summits” in 2007 and 2008 at the same locale. Motor Summit supports various ongoing processes of the Electric Motor Systems Annex of the International Energy Agency’s Efficient Electrical End-Use Equipment program (IEA 4E EMSA), namely:
- European Union’s Energy-using Products Ecodesign Directive;
- Harmonized IEC (International Electrotechnical Commission) motor testing and energy classification standards; and
- NEMA Premium Motors minimum efficiency performance standard (MEPS), which became U.S. law in Dec. 19, 2010 (January 2011 in Canada).
Summit segments consisted of “International strategy day” (Oct. 27), “Swiss implementation day” (Oct. 28), and two EMSA workshops: “IEA 4E: Testing Centers,” and “New Motor Technology” (on Oct. 26 and Oct. 28, respectively).
Presentation topics ranged widely from efficiency assessment of motor systems—including pumps, fans, and variable-frequency drives (VFDs)—to associated testing methods and to market potential for new technologies, and more. (A systems view of energy efficiency and permanent magnet motor technology are covered in a separate online article.) Other Summit topics included VFD testing methods and efficiency standards developments—including that for “small motors”—as outlined below.
Standards developments, VFDs
As presented in “New IEC Standards for Motor Efficiency Classes and Testing,” Dr.-Ing. Martin Doppelbauer, manager, design and development motors, SEW Eurodrive GmbH & Co KG, Germany, explained differences between standards and regulations and provided an overview of European energy-efficiency standards for industrial motors. Focus was on IEC 60034, which has several parts dealing with such items as efficiency test methods, a guide for selecting/applying efficient motors and VFDs, and motor efficiency class definitions.
IEC 60034-30 covers the latter area and has defined four international efficiency (IE) classes to harmonize general-purpose, line-fed, three-phase, squirrel-cage, ac induction motors, namely: standard efficiency (IE1), high-efficiency (IE2), premium efficiency (IE3), and super-premium efficiency (IE4). IE2 compares to EPAct and IE3 to NEMA Premium performance standards specified in the U.S (see below).
The European Union’s regulation EC No. 640/2009, has implemented energy-efficiency requirements in Europe based on IE class definitions, which become mandatory in three time steps:
- IE2 efficiency on June 16, 2011 for motors of 0.75-375 kW power range;
- IE3 efficiency on Jan. 1, 2015 for motors of 7.5-375 kW power range; and
- IE3 efficiency on Jan. 1, 2017 for motors of 0.75-375 kW power range.
EC 640/2009 recognizes that VFDs can often save much more energy than energy-efficient motors alone. Premium-efficiency requirements (starting in `15 and `17) apply to constant-speed, line-fed motors only, explained Doppelbauer. “Motors in variable-speed drive applications are just required to be high-efficient (IE2),” he said. “This should give users a small incentive to switch from constant speed to variable speed wherever [such drives are] useful.”
Doppelbauer also mentioned some noteworthy future projects of IEC Technical Committee 2 and its working groups 28 and 31. He is convener of WG 31. These tasks include
- Future efficiency standards developments for ac induction motors (namely IE4);
- Possible introduction of other motor types: single-phase induction, PM synchronous, reluctance synchronous, motors specifically built for VFD operation, etc; and
- Introduction of a new state-of-the-art energy-efficiency class (IE5).
Also see Ref 1.
Importance of VFDs to motor system efficiency was explored by Pierre Angers, P. Engineer at the Energy Testing Laboratory of Hydro-Quebec (Canada), in “Variable Frequency Drive Testing Methods.” The context was to establish appropriate testing procedures and ability to compare efficiency of VFD systems (drive, motor, and connected system) at different loads and speeds.
An increasing number of nations worldwide have, or are adopting, minimum efficiency performance standards (MEPS) for industrial motors—see table. Two papers presented progress in developing motor standards in Asia, namely in China and India, respectively. These were “Small Motors and Pumps Standards in China,” by Zhang Xin, China National Institute for Standardization; and “New Motor Standards in India,” by Milind Raje, director of Energy Solutions, International Copper Association (India).
Rob Boteler, director of marketing at Nidec Motor Corp. (and chairman of NEMA Energy Committee), discussed current energy-efficiency measures in the U.S. in his presentation “Small Motors Regulations Update.” However, he first reviewed MEPS developments for integral horsepower (hp) motors.
Surprisingly, this is an area where the U.S. has taken worldwide leadership. Progress has come in three stages:
- Environmental Policy Act (EPAct 1992) implemented in 1998 for general purpose, T-frame, single-speed, squirrel-cage induction motors in the 1-200 hp (0.75-150 kW) range. This corresponds to IEC’s level IE2;
- Energy Policy Act of 2005 (EPAct `05) that established higher NEMA Premium (IE3 level) efficiency ratings as the basis for federal motor purchases; and
- Pending implementation passed by the U.S. Congress on 19 Dec. 2010 as part of the Energy Independence & Security Act (EISA 2007) that extends efficiency coverage for induction motors from 1 to 500 hp (Premium Efficiency, IE3).
Boteler mentioned that EISA 2007 includes motor varieties and designs previously exempted from minimum efficiency requirements. The following are now included: U-frame, NEMA Design C, close-coupled pump motors, footless motors, vertical solid shaft normal thrust motors, eight-pole (900 rpm), and polyphase motors with voltage of not more than 600 V (other than 230 or 460 V). However, motors sized between 200 and 500 hp need only meet EPAct 92 efficiency ratings, according to Boteler.
Attention of the U.S. Dept. of Energy (DOE) has also been drawn to energy efficiency of small electric motors—generally below 1 hp rating, but extending up to 3 hp for some types. A multi-year process culminated in a so-called DOE Final Rule, “Energy Conservation Program: Energy Conservation Standards for Small Electric Motors,” published March 9, 2010 in the Federal Register (10 CFR Part 431).
The ruling adopts energy conservation standards for general-purpose, polyphase (actually, three-phase) motors ¼ through 3 hp (0.18-2.2 kW) with 2-, 4-, and 6-pole designs and 42 through 56 frame sizes. Also covered are single-phase, capacitor-start motors of the same power range and pole count. Applicable IEC motors and corresponding frame sizes are likewise included. Effect date is five years after publication date in March 2015.
DOE’s new ruling has drawn disagreement from motor manufacturers. Nidec Motor Corp.’s Boteler (and others) have pointed out that efficiency rule making is more complex for this product sector. Fractional hp motors have different designs and types; more frame size possibilities; more diverse applications; fewer operating hours; and less recognized efficiency testing methods compared to larger induction motors used in industrial and commercial applications.
Moreover, motor manufacturers disagree with the definition of “small motor” in DOE’s Final Rule, based on which NEMA has filed a lawsuit against the Rule. The good news is that substantial time remains to resolve any differences before the rule’s effective date of March 2015.
Organizers and sponsors of Motor Summit 2010 were The Swiss Agency for Efficient Energy Use (S.A.F.E.), in collaboration with the International Energy Agency’s 4E EMSA and the national SwissEnergy program. Control Engineering was a participant at Motor Summit 2008.
For full content of the Motor Summit 2010 program, visit http://www.motorsummit.ch
Frank J. Bartos, P.E., is a Control Engineering contributing content specialist. Reach him at firstname.lastname@example.org.
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