New Motor Efficiency Standards: What Motor Users Need to Know

New legislation, namely the Energy Independence and Security Act (EISA) of 2007, aims to increase production of renewable energy; increase efficiency of products, buildings and vehicles; and promote research and deployment of greenhouse gas capture and storage. The eventual goal is to move the United States toward greater autonomy in acquiring resources to meet its energy needs. The one page of the law that focuses on motor efficiency will significantly impact motor design and selection for machinery designers. Motors manufactured after December 19, 2010 must comply with the new rules defined in EISA, but that’s an issue for OEMs. How will this legislation affect the end-user?

motorefficiency_largeFirst, let’s understand the new regulations, which will result in a significant jump in motor efficiency. For instance, a 5.0 hp, 4-pole TEFC induction motor required a minimum efficiency of 87.5% under the old legislation, which mainly applied to three-phase general-purpose induction motors; it now requires 89.5% under the new regulations. Under the old act, the energy efficiency levels for induction motors were known as EPAct levels. The new regulation re-classifies them as Subtype I, so these motors, manufactured alone or as part of another piece of equipment, will be required to have nominal full-load efficiencies that meet the levels defined in NEMA MG-1 (2006) Table 12-12; also known as NEMA Premium® efficiency.

A completely new category of motors was created under the new EISA law regulating efficiency for motor designs that have not been covered under any previous legislation. These motors are called out as Subtype II category and defined as motors incorporating design elements of general purpose motors (subtype I) but are configured as U-frame motors, Design C motors, close-coupled pump motors, footless motors, vertical solid shaft normal thrust motors that are tested in a horizontal configuration, eight-pole motors (900 rpm), and polyphase motors with less than 600 volts. Subtype II motors between 1 and 200 hp as well as NEMA Design B motors with horsepower ratings above 200 hp and not greater than 500 hp, and fire pump motors are all required to have nominal full-load efficiencies as defined in NEMA MG-1 (2006) Table 12-11, also recognized as EPAct efficiency levels.

In addition to these new laws for polyphase motors, small motors in two-digit frame series (including single-phase) are being discussed at a series of public meetings held by the Department of Energy (DOE) throughout 2009. These discussions with motor manufacturers, energy efficiency advocates and other interested parties are expected to establish minimum efficiency standards for small motors (two digit frame series motors) for the first time. The DOE is proposing test procedures for measuring the efficiency of small electric motors, including both single-phase and polyphase, and to update the industry references and clarify the scope of coverage for the DOE’s existing test procedure for electric motors.

Prior to this legislation, from an OEM designer’s point of view, motor choice focused primarily, in descending order, on price, size, noise-level and weight. However, a recent survey has shown that those OEMs’ customers believed availability, reliability and price were the top three issues. Until the EISA legislation, neither the OEMs nor their customers considered efficiency important enough to factor into a machine’s overall design. Now, rising energy costs and the new legislation are moving efficiency to the top of everyone’s checklist.

End-users will not have to replace machinery currently in use, but if they want to replace a motor in an existing machine, they may have to call the OEM, which will supply them with a motor that meets the most current regulations. The same expectations of fit and form will need to be met—the new motor may match the performance of the one the end-user just took off his machine, and even be more efficient, but it may not have the exact same dimensions. This may require some “engineering on-the-fly” to make it fit. To make a significant impact, the new regulations must affect all motors covered by the legislation, not just a small percentage.

Depending on the application, it may be more cost-efficient to replace the equipment itself rather than just the motor. This is more likely to occur in machinery run by smaller motors, as opposed to simply replacing the component motor, because form and fit will pose a greater challenge in more compact equipment. With larger motors, this is not so much of an issue—speeds may change and the new motor may require some different control schemes, but the frame sizes will likely remain the same.

From an end-user perspective, pricing will be impacted by the new regulations. There are more active materials (copper and steel) in these new motors, and it’s safe to presume the OEMs will pass this cost along to their customers. Because of this, more than ever, end-users need to carefully evaluate their options in the repair-versus-replace
decision-making process.

Advanced Energy helped pioneer the theories of Motor Management (MM) for end users with its first publication of the HorsePower Bulletin for the DOE in 1991. This document is a useful guide to any facility wishing to implement motor management. Electric motors convert approximately 70% of all electric energy delivered to a manufacturing facility into mechanical energy. The purchase price for an average motor makes up approximately 3% of the total lifecycle cost to own and operate. Energy costs make up the rest. Managing motors could pay big dividends in reducing energy costs and increasing process reliability.

Motor Management (MM) refers to understanding, tracking and making planned decisions regarding any motor population. MM theories have not changed since that first HorsePower Bulletin in 1990, and there are now many tools offered by manufacturers, government, and energy efficiency advocates that address them. At its core, motor management allows for making good, planned decisions in advance of motor failure to determine if a motor should be replaced or repaired, and having an action plan in place that facilitates that decision.

At the heart of the process is making the repair versus replace decision BEFORE a motor fails. This is typically done through motor surveys. Advanced Energy offers a survey that allows anyone to collect nameplate data from a motor and send it to the Advanced Energy team, who processes that data and provides a calculation of how much could potentially be saved by upgrading to a higher efficiency motor. When repair is the proper choice, making certain your repair vendors can maintain efficiency is critical to long-lasting performance and keeping energy costs low. Advanced Energy can help here too by certifying your motor repair vendors through the Proven Efficiency Verification Program.

When evaluating a motor application, it is important to not only consider purchase price, but other factors including total life cycle cost, energy costs, ROI, etc. Factors that maximize return on investment in a motor in terms of efficiency include how many hours per year the motor runs and the cost of energy at your location. The average motor easily consumes 50 to 60 times its initial purchase price in electricity costs in a typical 10-year lifetime. Most importantly, the capital cost of the new motor represents approximately two to three percent of its lifecycle cost. In many instances it is better to negotiate for the most efficient motor you can purchase, because as much as 98 percent of the true cost is going to be the energy you put into that motor in its 10-year life expectancy.

Another way to maximize ROI is to inventory motors in terms of which ones operate the most hours and are critical to the process, and replace those motors first. Switching out a motor may provide great efficiency savings, but if that motor is not particularly critical to the operation or runs less than 4,000 hours per year, the savings might not be significant enough to justify replacement. Focus first on motors that would impact overall productivity and revenue if they experienced any downtime. Some motors don’t cost the company as much as others when they fail and those should be a secondary concern when surveying motors for greater efficiency.

Approximately four out of five motors that fail are repaired rather than replaced, and Advanced Energy’s research has shown that as little as 12 percent of motor users consider energy efficiency in making the decision between replace and repair. Perhaps these new regulations will raise awareness of the issue and help more motor users put a Motor Management plan into action. Not only can it result in increased productivity and energy efficiency, but it can also result in lower operating and maintenance costs.

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NEMA Premium Purchase Decisions

At the time of publication, new legislation has been proposed which could significantly impact the purchasing decisions for NEMA Premium motors. NEMA reports that a provision passed by the Senate Energy Committee could allow stimulus money to offer rebates of $25.00/HP for NEMA Premium motors purchased and $5/HP credit for each non-NEMA Premium motor that is crushed. Details on the “crush for credit” program can be seen at http://tinyurl.com/curhsl

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Advanced Energy and AutomationDirect

Advanced Energy is a leading provider of testing and consulting services in the motor and drives industry. An independent source for accurate and unbiased information, the non-profit helps organizations make decisions that will impact their reputation and financial future. Advanced Energy’s motors and drives services are applied across a wide range of industries including motor users, OEMs, motor manufacturers, distributors and importers, and governments.

AutomationDirect approached Advanced Energy for assistance in selecting a supplier for a line of general-purpose AC motors. Joe Kimbrell, the Drives, Motors and Motion Control product manager at AutomationDirect, had already selected several possible suppliers for evaluation.

Advanced Energy took several steps to collect accurate information. First, a series of motor build-and-inspection analyses were performed on motors from each of the potential suppliers. Inspections were done on a statistical sample of motors throughout the range of motor sizes and types AutomationDirect wished to add to its portfolio of products. This effort narrowed the field down to one supplier and resulted in the introduction of the IronHorse line of motors from AutomationDirect. Extensive motor and drive testing was then performed to validate inverter ratings for this new product line.

“At AutomationDirect, we are in the business of helping our customers apply their product,” said Joe Kimbrell, AutomationDirect. “We needed unbiased expert evaluation of motor design and manufacture, so we turned to Advanced Energy to help us determine the best quality motors for our customers’ needs.”

View products from AutomationDirect that relate to this article:
Marathon NEMA Premium Motors

by Kitt Butler,
Advanced Energy

Originally Published: March 1, 2009