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Leeson Literature Epact

Jun 03, 2018



  • 8/12/2019 Leeson Literature Epact






  • 8/12/2019 Leeson Literature Epact


    FOREWORDJanuary 1998

    Grafton, Wisconsin

    Today is truly an exciting and challenging time for specifiers, buyers, users andmanufacturers of industrial electric motors. It is a time of change in the motor industry

    rivaled, in recent times, only by the introduction of re-rated T frame motors in the 1960s.

    But there is a difference between that change and this one. The T frame evolution was

    perpetuated by the motor industry itself, driven by economics and market force realities.

    Today, however, we have seen a government mandate.

    As the law of the land, most industrial motors produced after October 24, 1997, were

    required to operate at the mandated efficiency levels prescribed by the Energy Policy Act

    of 1992. These legislated efficiencies are not challenging from a design or manufacturingviewpoint. In fact, mandated efficiency levels are generally lower than the premium-

    efficiency motors available from major manufacturers for many years. The major change

    of EPACT has been felt in the increased cost to motor users, as mandated-efficiency

    Design B motors became the new standard used in many industrial applications and as

    components in a wide variety of industrial machinery. In addition, many motor users have

    found that NEMA Design C torque motors, which are not covered by EPACT mandates,

    are excellent choices for many applications where a bit more torque is desirable. And their

    standard efficiencies may be perfectly adequate when balanced against actual duty cycle

    or the lower up-front cost.

    Guidelines as to what constitutes a motor that can be used for general purposes and is

    therefore covered by EPACT have been clarified. The clarifications have come from

    NEMA (the National Electrical Manufacturers Association) and from the Department of

    Energy, which has the official responsibility for rulemaking and enforcement of EPACT

    mandates. These guidelines are included in Appendix A of this booklet. Also included in

    this revised booklet, in Appendix B, is information on IEEE 112B, the required efficiency

    testing procedure under EPACT.

    As always, LEESON welcomes your comments and suggestions. Please write, fax, or

    e-mail us through our World Wide Web site (, and leave your message.

    We will be delighted to respond.

    We look forward to helping serve you in your industrial electric motor needs.

  • 8/12/2019 Leeson Literature Epact


    t has probably been a topic of discussion since the beginnings of the electric

    motor industry. Certainly, it has been a major topic since the Arab oil

    embargo of the 1970s and, it seems, THE topic of discussion in the motor

    industry since the federal governments passage of the Energy Policy Act

    (EPACT) in 1992. Motor efficiency: How completely an electric motor converts

    electricity into mechanical work. Does 80% of the electrical energy we feed intoa motor become work at the end of the shaft? Does 90%? Yesterday, it was

    mostly a question for the curious. Today, driven first by higher energy costs,

    then by incentive programs of electric utilities, and most recently by federal

    legislation in the form of EPACT, which took effect in late 1997, motor

    efficiency has become an imperative.

    Here, in a nutshell, is what the law means to the industrial motor user, whether

    the motors are for replacement use on existing applications, or components of

    another machine. Three-phase, general-purpose, NEMA T frame motors of 1

    through 200 HP, manufactured after October 24, 1997, must meet government-

    mandated efficiency levels. These EPACT levels are higher than those of most

    manufacturers previous standard efficiency motors, but generally not higher

    than many manufacturers long-standing premium-efficiency lines. So, in that

    sense, motors of the new efficiencies are not really all that new at all. The real

    difference is in how much more widespread their manufacture, availability and

    requiredbecame as of late 1997.

    Why Is Motor Efficiency Important?

    Electric motors have a huge impact on overall energy usage. Between 30 and 40

    percent of all fossil fuels burned in the world are used to generate electricity,

    and a large portion of that electricity goes to run motors. Nearly all estimates

    say that at least 60% of electricity in the United States is used to power motors.

    Given the overwhelming number of small motors in consumer use, well over

    half of motor power demand falls to this (for now) unregulated motorsegment. But that still leaves a sizable power demand within the industrial

    motor population, at current electric rates perhaps $30 billion worth of electrical

    power per year. This means that within the overall industrial motor segment,

    every percentage point gain in overall motor efficiency translates into $300

    million of yearly savings. Maximizing industrial electric motor efficiency is

    clearly important. This is true in public energy policy terms, and

    environmentally in reduction of greenhouse gases associated with fossil fuel

    burning. Plus it is also good business practice.

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    Open Motors2 POLE 4 POLE 6 POLE

    Nominal Nominal NominalHP Efficiency Efficiency Efficiency

    1.0 82.5 80.0

    1.5 82.5 84.0 84.0

    2.0 84.0 84.0 85.5

    3.0 84.0 86.5 86.5

    5.0 85.5 87.5 87.5

    7.5 87.5 88.5 88.5

    10.0 88.5 89.5 90.2

    15.0 89.5 91.0 90.2

    20.0 90.2 91.0 91.025.0 91.0 91.7 91.7

    30.0 91.0 92.4 92.4

    40.0 91.7 93.0 93.0

    50.0 92.4 93.0 93.0

    60.0 93.0 93.6 93.6

    75.0 93.0 94.1 93.6

    100.0 93.0 94.1 94.1

    125.0 93.6 94.5 94.1

    150.0 93.6 95.0 94.5

    200.0 94.5 95.0 94.5250.0* 94.5 95.4 95.4

    300.0* 95.0 95.4 95.4

    350.0* 95.0 95.4 95.4

    400.0* 95.4 95.4

    450.0* 95.8 95.8

    500.0* 95.8 95.8

    Enclosed Motors1.0 75.5 82.5 80.0

    1.5 82.5 84.0 85.5

    2.0 84.0 84.0 86.5

    3.0 85.5 87.5 87.5

    5.0 87.5 87.5 87.5

    7.5 88.5 89.5 89.5

    10.0 89.5 89.5 89.5

    15.0 90.2 91.0 90.2

    20.0 90.2 91.0 90.2

    25.0 91.0 92.4 91.7

    30.0 91.0 92.4 91.7

    40.0 91.7 93.0 93.050.0 92.4 93.0 93.0

    60.0 93.0 93.6 93.6

    75.0 93.0 94.1 93.6

    100.0 93.6 94.5 94.1

    125.0 94.5 94.5 94.1

    150.0 94.5 95.0 95.0

    200.0 95.0 95.0 95.0

    NEMA 12-10 efficiency levels the basis for EPACT mandates.

    * motors larger than 200 HP are not covered by EPACT `92.

    Full-Load Efficiencies of Energy Efficient Motors

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    EPACT 92 Covers...

    General purpose

    T-frame(143T-447T) Foot mounted Single speed motors NEMA Design A or B performance Continuous duty 1 - 200 HP 3600, 1800, 1200 RPM designs 230/460 V, 3 phase, 60 Hz

    Under EPACT, many kinds of industrial motors are required to have efficiency levels nearly as high

    as these premium-efficiency WATTSAVER motors.

    What EPACT Specifically Says About Motors

    Three-phase, 1 through 200 HP, general-purpose, T frame . . . those are the

    key elements to remember about which motors will or will not be covered

    by the EPACT guidelines in late 1997. Here are the specifics:

    Any non-exempt motor manufacturedafter October 24, 1997, must meet

    the EPACT efficiency levels, as administered by the Department of Energy

    and related agencies. These levels are the same as those listed in the MG-1-

    1993 standards published by NEMA, the National Electrical ManufacturersAssociation. They are shown in Table 12-10 of that publication, so you will

    often hear the EPACT efficiency levels equated with NEMA 12-10. (See

    the table on previous page.)

    Note the emphasis in the previous paragraph on manufactured. The law

    clearly does not require any motor user to replace an existing motor with a

  • 8/12/2019 Leeson Literature Epact


    - 6 -

    higher-efficiency model

    (though in some

    applications you might

    want to do so for

    economic reasons based

    on energy dollars saved.)And because motor

    companies are manu-

    facturing motors and

    filling inventory chan-

    nels all the time, there

    will certainly be standard

    motors in the pipeline

    for months and probablyeven years to come.

    Customers may buy and

    install these pre-EPACT-

    manufactured motors

    (presumably at a lower

    price than the newer

    high-efficiency models) as long as theyre available. Similarly, the law makes

    no reference to used or rewound motors. Those may be bought at will,regardless of efficiency, though, over time, its likely that the marketplace will

    demand a proven, if not certified, level of efficiency from rewound or otherwise

    reworked motors as well.

    Note also the term non-exempt motor. While its scope is certainly

    widespread, covering perhaps half of all industrial motors, EPACT does not

    address all types of motors. Its focus is on small to medium-horsepower AC

    motors used in general industrial applications. For example, it states only three-

    phase 230/460 VAC motors from 1 through 200 HP. Further,

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