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Design by Objective: Maximizing efficiency

April 1, 2001
Doing more with less, and doing it smarter, are keys to efficiency

Rising gasoline prices. Double-digit rate increases for winter heating fuel. California’s blackouts. Energy in its various forms is all over the news these days. Considering today’s problems, which aren’t expected to magically disappear any time soon, the key to both saving money and increasing creature comfort is efficiency — doing more with less and saving energy with smarter appliances, automobiles, and factories. From the board room to the laundry room, just about everyone is interested in the careful use of energy these days.

Awareness campaigns flourishing

Dozens of industry and government organizations are creating initiatives and trying to raise awareness about efficiency, particularly motor efficiency. For example, the motor and generator section of the National Electrical Manufacturers Association (NEMA), an organization of motor manufacturers, announced in October 2000 that it would establish a “NEMA Premium” energy efficiency motor marketing campaign for four main reasons: electric motors have a significant impact on the total energy operating cost for industrial, institutional, and commercial buildings; electric motors vary in terms of efficiency; the NEMA Premium program will assist purchasers in identifying higher efficiency motors that will save money and improve system reliability; and NEMA premium labeled electric motors will assist users in optimizing systems and will reduce electrical consumption, thereby reducing pollution associated with electrical power generation.

Based on U.S. Department of Energy (DOE) data, it is estimated that this program could save 5.8 GW of electricity and prevent the release of nearly 80 million metric tons of carbon into the atmosphere over the next 10 years. This is equal to keeping 16,000,000 cars off the road.

Premium plans from NEMA

Under the Energy Policy Act of 1992 (EPAct), general purpose integral horsepower motors, 1 to 200 hp, are regulated products and have mandated minimum energy efficiency levels. The NEMA motor and generator section’s energy management task force has worked with DOE officials to implement the EPAct requirements and related rules on motor testing and labeling. The DOE issued final rules for these products on October 5, 1999.

One of NEMA’s goals is to be proactive in offering high energy efficiency products that meet the needs and applications of users and OEMs, providing energy cost savings through reduced energy consumption and providing purchasers with the ability to take advantage of utility industry motor rebate programs. By being proactive, the industry seeks to maintain ownership and provide leadership in product standardization and efficiency definitions, grow the premium motor market, and reduce the need for additional federal regulation of motor products. “What we really need, and what would be a major breakthrough in this industry, is a common definition of a ‘premium’ motor,” says Kyle Pistor, industry director for NEMA’s motor and generator section.

The premium efficiency motor marketing campaign is based on present day NEMA Design A and B motor performance, including locked rotor current. Premium motor products are available and sold today and operate with present day motor support equipment. Products are tested and name-plated in accordance with existing standards including the NEMA MG 1 standard. No changes to the National Electrical Code or UL safety requirements would be needed.

The task force developed the NEMA Premium program based on a consensus definition of “premium efficiency” and the use of a consistent label for premium products. The program will cover many more motor types and sizes than those covered under EPAct, including 1 to 200 HP definite and special purpose motors, motors up to 500 HP and medium voltage motors.

NEMA will trademark “NEMA Premium” and a logo for use in this marketing campaign and the label will only be used with those products that meet or exceed the premium motor efficiency levels. Only partnering manufacturers may use the premium label through a memorandum of understanding (MOU) with NEMA. The MOU and label are in final stages of development, says Pistor.

According to NEMA, the motor industry believes that a consistent recognized label will provide member companies and customers with the right marketing tool to more rapidly transform the motor market from lower efficiency products to premium efficiency products.

NEMA is working with other interested parties and stakeholders to obtain support and endorsement. These include the DOE, Environmental Protection Agency, Consortium for Energy Efficiency, American Council for an Energy Efficient Economy, Electrical Apparatus Service Association, Hydraulic Institute, Compressed Air and Gas Institute, Copper Development Association, National Association of State Energy Officials, National Association of Manufacturers, and the Edison Electric Institute.

Motor decisions matter, says CEE

The Consortium for Energy Efficiency (CEE), working in parallel with NEMA and others, has established its own national campaign called “Motor Decisions Matter.” The goal of this campaign is to help industrial customers maximize their productivity amidst growing concern over electric utility restructuring and escalating energy prices. Industrial electric motordriven systems consume approximately 679 billion kWh annually — 23% of all electricity in the U.S. — representing the largest single category of electricity use in the country. Because many motor systems operate 40 to 80 hours per week or more, even small increases in efficiency can yield huge energy savings. However, knowledge and adoption of motor system efficiency measures is very low for a variety of reasons: low priority of energy efficiency among capital investment and operating objectives; general lack of awareness among facilities managers, equipment distributors, engineers, and manufacturers’ representatives about strategies to improve motor system efficiency; low level of staffing for facilities maintenance; and conflicting incentives for equipment and service providers to promote efficient equipment. The cumulative result of these barriers is that the motor system market is largely first-cost driven. Consequently, the connection is not made between efficient motor systems and manufacturing performance and competitiveness.

So, the goal is to raise awareness, in order to help senior management appreciate how improved motor management relates to business performance and then take appropriate action. The target audience of this campaign is senior-level decision makers within industrial companies, such as corporate and plant executives, as well as corporate financial personnel. The proposed time frame is June 2001 to June 2002.

DOE’s disturbing findings

According to the U.S. Industrial Motor Systems Market Opportunities Assessment, one component of the DOE’s Motor Challenge Program, there is a lot of work ahead and here’s why.

• Most big motor purchase decisions are made at the plant level. Even among multi-site organizations, 91% of respondents report that all motor purchase decisions are made at the plant level.
• Awareness of the availability of energy-efficient motors and understanding of their performance advantage is low. Only 19% of respondents report being aware of “premium efficiency” motors.
• Only 22% of companies surveyed report that they had purchased any efficient motors in the past year.
• Motor specifiers most often use the size of the failed motor as a key factor in selecting the size of a new motor. Twenty-nine percent use the size of the failed motor as the only factor in a sizing decision. This can result in persistent oversizing of motors, which leads to inefficient operation.
• Only 11% of respondents report having written specifications for motor purchases; only two-thirds of these customers include efficiency in their specifications.
• Reducing capital costs is the most important consideration driving decisions on whether to rewind or replace failed motors. Only 12% of respondents report that they consider the lower energy operating costs of new motors in these decisions.
• Except among the very largest facilities, the frequency with which systemlevel improvements are undertaken is very low.

Motor design matters

What does it take to produce a highly efficient motor and why is efficiency so important? Common themes are quality materials and effective, streamlined design.

“Over the life cycle of a motor, electricity usage is 98% of the cost, while motor purchase price is only two percent,” says Jerry Peerbolte, VP of marketing for Baldor Electric Co., Fort Smith, Ark. Purchasers often tend to focus on the initial purchase price of a premium motor, which may be a couple hundred dollars more than a non-premium, rather than considering the thousands of dollars in energy savings over the motor’s life. In addition to energy savings, premium motors have other benefits. For one, they run cooler than their non-premium cohorts, avoiding other unpleasant heat-induced machine malfunctions. Premium motors are also balanced better, leading to less machine vibration, which also impacts efficiency and machine performance.

To make machines run even better, add an adjustable speed drive to the motor, such as an inverter, and you’ll increase efficiency another 20 to 40 percent. A prime example of this is with motors used in HVAC applications. Rather than turning an air conditioning motor on and off full blast several times a day, an inverter can be used to drive the motor in a much more efficient manner, throttling down and speeding up as required to hold a constant temperature.

“A typical misconception is the belief that 92% and 94% efficiency ratings are about the same. It’s not true. When you consider that a 50 hp motor can use $25,000 in energy per year, and multiply that by a 10-year life cycle, the percentage differences really start to add up,” says Peerbolte.

Design factors that go into building more efficient motors include things like better steel, improved magnet wire, more steel and copper in the unit, tighter tolerances with air gaps controlled to reduce energy losses, better varnishes, and different slot shapes. Since these motors run cooler, they don’t need as big an external cooling fan either.

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