November 28, 2
September 09, 2013
VIA EMAIL TO: ElectricMotors2012TP0043@ee.doe.gov
Ms. Brenda Edwards
US Department of Energy
Buildings Technologies Program
Mail Stop EE-2J
1000 Independence Ave, SW
Washington, DC 20585-0121
NEMA Comments on Energy Conservation Program:
Test Procedures for Electric Motors Notice of Proposed Rulemaking
Docket Number: EERE-2012-BT-TP-0043
RIN: 1904-AC89
Dear Ms. Edwards,
The National Electrical Manufacturers Association (NEMA) appreciates the opportunity to
provide the attached comments on the Department of Energy’s Notice of Proposed Rulemaking
for Test Procedures for Electric Motors. These comments are submitted on behalf of NEMA
Motor and Generator Section member companies.
As you may know, NEMA is the association of electrical equipment and medical imaging
manufacturers, founded in 1926 and headquartered in Arlington, Virginia. Its 400-plus member
companies manufacture a diverse set of products including power transmission and distribution
equipment, lighting systems, factory automation and control systems, and medical diagnostic
imaging systems. The U.S. electroindustry accounts for more than 7,000 manufacturing
facilities, nearly 400,000 workers, and over $100 billion in total U.S. shipments.
Please find our detailed comments below. We look forward to working with you further on this
important project. If you have any questions on these comments, please contact Alex
Boesenberg of NEMA at 703-841-3268 or alex.boesenberg@nema.org.
Sincerely,
Kyle Pitsor
Vice President, Government Relations
NEMA Comments on Energy Conservation Program:
Test Procedures for Electric Motors Notice of Proposed Rulemaking
Executive Summary:
We call DOE’s attention to the fact that many of our comments are heavily caveated, based on
industry’s perception of the status of the Electric Motors Energy Conservation Standard, which
is also in progress and nearing the NOPR stage. In several instances, our comments hinge on
a lack of understanding of how the issue at hand will be applied to the final product and to the
marketplace, ergo how the Energy Conservation Standard will be adjusted during its further
development. NEMA has commented previously in other rulemakings regarding our strong
concerns over the DOE attempting to develop Test Procedures and Energy Conservation
Standards in parallel, and this rulemaking is another case where one is outpacing the other and
we are sorely tried to comment accurately. Our concerns continue to grow over the increasing
potential for mistaken and misplaced adjustments to each rulemaking during comments
processing. The difficulty in formulating comments, and the potential for misapplication of
comments, is causing significant trouble for industry, and the resulting mismatch between
interrelated rulemakings is in danger of undermining the public comment process.
Previously, it was normal to pursue and complete the Test Procedures rulemaking before
delving deeply into the corresponding Energy Conservation Standard for a product. The DOE
should return to this approach. Until then, we note several instances in the following comments
where a comment is written with more than one potential meaning, depending on how the
Electric Motors Energy Conservation Standard evolves. In cases where the DOE selects some
new option not present, or where the industry’s interpretation proves incorrect, we expect that
stakeholders will be advised and allowed opportunity to comment either through interviews or by
Supplemental NOPR before the publication of the Final Rule.
Due to the length of these comments, we offer the following summary of significant concerns
relative to the establishment of definitions for various types of electric motors. Additional details
for each, and numerous more issues, appear in our detailed comments which follow this
Summary.
1) The Proposed Definitions Lack Sufficient Clarity For Regulation Purposes
In the complex world of motors of varied shapes and performance it is necessary that the
definitions used to refer to motors which are covered products or exempted products in 10 CFR
be both clear and complete. DOE expresses this concern in several places in the present
NOPR. For example, in Section III-C on page 38461 of the NOPR DOE wrote “DOE
understands that many terms and definitions applicable to motors and used in common industry
parlance for voluntary standards and day-to-day business communication are not necessarily
defined with sufficient clarity for regulatory purposes.” Yet, many of the definitions which DOE
has proposed are basically copies of the definitions from voluntary standards and lack the clarity
which DOE has stated is necessary. This is in contrast to the definitions of different types of
electric motors included in §431.12 of 10 CFR over the years.
An example of some level of completeness can be seen in the first definition of “electric motor”
established by Congress in EPAct of 1992:
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“The term `electric motor' means any motor which is a general purpose T-frame,
single-speed, foot-mounting, polyphase squirrel-cage induction motor of the
National Electrical Manufacturers Association, Design A and B, continuous rated,
operating on 230/460 volts and constant 60 Hertz line power as defined in NEMA
Standards Publication MG1-1987.”
The above definition of “electric motor” consisted of both the construction and performance
criteria necessary to distinguish such motors from all of the other types of motors.
Congress also provided definitions of “special purpose motor” and “definite purpose motor” to
identify types of motors which were not “electric motors” and were exempted from the efficiency
standards.
In 1997, DOE published a statement of “Policies on Coverage and Enforcement of Energy
Efficiency Requirements for Electric Motors”1. Explanations were provided therein regarding
how DOE interpreted certain common motor construction or performance characteristics to
determine whether a motor with such characteristics fit within the categories of being an “electric
motor”, a “special purpose motor”, a “definite purpose motor”, or was outside of the scope of
“electric motor”. A table of 54 example characteristics was provided with identification as to
which category a motor with each characteristic belonged.
In 1999 DOE issued a Final Rule which created a new Part 431 for 10 CFR in which DOE
included an expansion of some of the construction and performance criteria within the EPAct
definition of “electric motor” in order to make it clearer as to what type of motor was considered
to be an “electric motor”. To provide additional clarification, DOE established a definition of
“general purpose motor”, as referred to within the definition of “electric motor”, that was different
from the motor industry voluntary standard definition of “general purpose motor” by including
those definite purpose motors that could be used in most general purpose applications. The
definition of “definite purpose motor” from EPAct was included, but with a clarification that such
motors also could not be used in most general purpose applications. The definition of “special
purpose motor” from EPAct was included with no changes. The “policies” statement of 1997
was included as Appendix A to the General Provisions of Subpart A. In later years the rules and
regulations relative to electric motors were moved to Subpart B.
In 2007 EISA replaced the single type of “electric motor” defined in EPAct with two different
types of electric motors: “general purpose electric motors (subtype I)” and “general purpose
electric motors (subtype II)”. Further, in addition to establishing efficiency standards for the two
different types of electric motors EISA established efficiency standards for “fire pump motors”
and certain “NEMA Design B, general purpose electric motors”.
In accordance with EISA, in a subsequent Final Rule (FR March 23, 2009) DOE changed 10
CFR Part 431 by replacing the definition of the single type of “electric motor” with the definitions
of the two types of electric motors as defined in EISA. At that time DOE pointed out the
possible confusion where EISA referred to a definition of “General Purpose” being in 10 CFR
431 while the actual term defined in 10 CFR 431 was “General purpose motor”. To provide
additional clarity, DOE expanded the EISA definition of “general purpose electric motor (subtype
I)” by including the content of the definition of “general purpose motor” from the then existing
version of §431.12. The definition of “general purpose electric motor (subtype II)” from EISA
1
See the link to the document under “Historical Information” at
http://www1.eere.energy.gov/buildings/appliance_standards/product.aspx/productid/50
3
was added to §431.12 without revision. When the definition of “electric motor” was removed
from §431.12 then the distinguishing construction and performance characteristics embodied in
that definition were also removed. That left a definition of a “general purpose electric motor
(subtype I)” defined solely on the interpretation of what constituted a “general purpose motor”.
In a later Final Rule (FR May 4, 2012), DOE apparently recognized the inadequacy of the
definitions in the 2009 Final Rule to properly identify the types of motors for which the efficiency
standards applied. To correct that problem DOE included a new definition of “electric motor”
derived from the first part of the previous definition of “electric motor” as “a machine that
converts electrical power into rotational mechanical power”. The definition of “general purpose
motor” was replaced by a definition of “general purpose electric motor” of equivalent definition.
This provided for removing the content of the definition of “general purpose electric motor” from
the definition of “general purpose electric motor (subtype I)”. For the purpose of additional
clarification, the definition of “general purpose electric motor (subtype I)” was expanded to
include the construction and performance characteristics from the earlier 1999 Final Rule
definition of “electric motor”. The “general purpose electric motor (subtype II)” inherited those
characteristics because a “general purpose electric motor (subtype II)” is essentially a “general
purpose electric motor (subtype I)” that differs in one or more particular characteristics. The
same was applied to the “NEMA Design B general purpose electric motor” when the condition of
being of a “general purpose electric motor (subtype I)” or “general purpose electric motor
(subtype II)” was added in identifying which type of “NEMA Design B general purpose electric
motor” the standards applied to. As a result of these revisions, the earlier more complete and
clearer definitions of the type of covered electric motors were restored. Regrettably, the 1997
Policies statement that was instrumental in explaining the DOE interpretation of “electric
motors”, “definite purpose motor”, and “special purpose motor” included in 10 CFR as Appendix
A to Subpart B was removed.
Important to examining the proposals in the present NOPR is the identification that a “general
purpose electric motor (subtype II)” differs from a “general purpose electric motor (subtype I)”
with regards to a difference in some particular design element related to either performance or
construction. Each of the seven identified design elements, such as being of footless
construction, is not sufficient by itself to completely identify a covered product.
On August 15, 2012 a group of interested Stakeholders submitted a Joint Petition requesting
that in lieu of increasing the efficiency standards for presently covered electric motors that DOE
consider the energy savings that would be obtained by increasing the scope of covered electric
motors by including some types of definite purpose motors and special purpose motors
presently exempted from standards. Those recommendations were based on the content of the
DOE 1997 Policies statement. In this NOPR DOE is proposing to include definitions for certain
types of electric motors which DOE previously classified in that 1997 Policies statement as
definite purpose motors or special purpose motors. DOE also proposes that some of those
types would continue to remain exempt. Also, DOE is proposing to add a provision to Appendix
B to Subpart B that refers specifically to the types of “definite purpose motors” and “special
purpose motors” for which definitions have been established.
The proposed definition of each new “electric motor” type in the NOPR must be examined to
determine if the proposed definition is sufficiently complete and clear for regulatory purposes, at
least as complete and clear as the present definitions of types of “electric motors” in §431.12
are. As an example, consider the proposed definition of “totally enclosed non-ventilated (TENV)
electric motor” found in the present NOPR:
4
“Totally enclosed non-ventilated (TENV) electric motor means an electric motor
(i.e., a machine that converts electrical power into rotational mechanical power)
that is built in a frame-surface cooled, totally enclosed configuration that is
designed and equipped to be cooled only by free convection.”
The proposed definition is essentially a copy of the definition found in 1.26.1 of the voluntary
NEMA MG1 Standard. In NEMA MG1 the definition is intended only to identify a particular
characteristic of a motor relative to the type of enclosure and the method of cooling of the motor.
This does not address the performance characteristics or any special construction
characteristics which a motor of such TENV construction designed in compliance with the
complete NEMA MG1 standard must have.
When examined in the context of the definitions presently in 10 CFR Part 431 it can be realized
that TENV is but a singular design element that distinguishes the complete motor, performance
and construction, from other motors of similar performance and construction. This is analogous
to the relationship between “general purpose electric motors (subtype II)” and “general purpose
electric motors (subtype I)”
The following conclusions can be reached based on the above proposed definition and
comparison to the present definitions of types of electric motors in §431.12:
 There is no requirement that a TENV electric motor be a single-speed motor.
Multispeed and variable speed motors of the defined mechanical construction fit the
proposed definition of TENV electric motor.

There is no requirement that the TENV electric motor be an induction motor.
Synchronous motors, permanent magnet motors, switched reluctance motors, etc.,
of the defined mechanical construction fit the proposed definition of TENV electric
motor.

There is no requirement that TENV electric motors be rated for continuous duty
(MG1) or duty type S1 (IEC). Intermittent duty, short-time duty, and all IEC duty
types of the defined mechanical construction fit the proposed definition of TENV
electric motor.

There is no requirement that the TENV electric motor be of the squirrel-cage (MG1)
or cage (IEC) induction motor type. Wound rotor induction motors of the defined
mechanical construction fit the proposed definition.

There is no requirement that the TENV electric motor be of the type which operates
on polyphase alternating current 60-Hertz sinusoidal power. Motors incorporating
the defined mechanical construction operating on direct current power, single-phase
power, multi-phase power, or any frequency all fit the proposed definition.

There is no specification of the applicable voltage or voltage range for TENV electric
motors. This encompasses TENV electric motors with form wound stators as well as
random wound. Efficiency levels relative to form wound windings are lower than
those for random wound windings. Also, for form wound stators the efficiency level
decreases with an increase in the voltage rating due to the additional insulation
material required for higher voltage levels. To include all voltage ratings would
require a multitude of different efficiency standards.
5

There is no specification that the TENV electric motors be built according to any
particular standard dimensions. TENV motors built in NEMA small, medium, and
large sizes, IEC sizes, or any other physical size would fit the proposed definition.

There is no requirement that TENV electric motors meet all of the performance
requirements of one of the following types: a NEMA Design A, B, or C motor or an
IEC Design N or H motor. NEMA Design D polyphase motors, all NEMA singlephase motors, and dc motors incorporating the defined mechanical construction fit
the proposed definition.

There is no indication that TENV electric motors are of the general class of “general
purpose electric motors”, “definite purpose electric motors”, or “special purpose
motors”. Whether or not the proposed new provisions of Appendix B to Subpart B
would apply to TENV electric motors is not obvious.
It should be obvious that the proposed definition of “TENV electric motor” is inadequate to meet
the complete and clear definition test. The proposed definitions for other types of electric
motors also fail the same test. The definitions need to be written to provide the necessary
clarity for regulation purposes.
2) NEMA Proposal For Adding Clarity To The Definitions
In the current NOPR DOE also states that “at this time, DOE is considering setting energy
conservation standards for only those motors that exhibit all of the following nine characteristics:
 Is a single-speed, induction motor,
 Is rated for continuous duty (MG1) operation or for duty type S1 (IEC),
 Contains a squirrel-cage (MG1) or cage (IEC) rotor,
 Operates on polyphase alternating current 60-hertz sinusoidal line power,
 Is rated 600 volts or less,
 Has a 2-, 4-, 6-, or 8-pole configuration,
 Has a three-digit NEMA frame size (or IEC metric equivalent) or an enclosed 56 NEMA
frame size (or IEC metric equivalent),
 Is rated no more than 500 horsepower, but greater than or equal to 1 horsepower (or
kilowatt equivalent), and
 Meets all of the performance requirements of one of the following motor types: a NEMA
Design A, B, or C motor or an IEC design N or H motor.”
The above construction and performance characteristics are basically those found in the
definitions and ratings of “general purpose electric motor (subtype I)” and “general purpose
electric motor (subtype II)”. NEMA notes, however, that in the above proposal “T-frame” in the
definition of “general purpose electric motor (subtype I)” was replaced with “three-digit NEMA
frame size”. NEMA assumes that DOE intended to refer to “three-digit NEMA frame number
series”, as in Table 4-2 of NEMA MG1-2009. A “frame number (size)” may be three or four
digits in length and designates a particular mounting dimension (2F) as well as the basic shaft
height (D) designated by the frame number series. While the intent of DOE may have been to
overcome some concerns relative to particular dimensions equated with standard T-frame
dimensions, this creates other unintended problems and confusion. According to NEMA MG12009, paragraph 4.2.2 there are 29 different frame letters or combinations of frame letters used
6
in combination with the frame number. Frame letters “T” and “U” are but two of those. Other
frame letters designate definite purpose motors or special purpose motors which DOE has not
covered in the NOPR. NEMA is of the opinion that, as noted in the following proposal, it is in
the best interest to have a proper definition of “electric motor” based on as many of the nine
characteristics as possible for all “electric motor” types.
Referring to “three-digit NEMA frame sizes (or series)” rather than “T-frame” makes it difficult to
distinguish between “general purpose electric motor (subtype I)” and “general purpose electric
motor (subtype II)” where at present electric motors with U-frame construction in a three-digit
NEMA frame series are defined as only of the second subtype. Comparison of the dimensions
for U-frame sizes in Part 11 of NEMA Standards Publication MG1-19672 to T-frame sizes in Part
4 of NEMA MG1-2009 clearly show that the “D” and “F” dimensions are the same for each
frame number for both “U” and “T”. The differences between “U-frames” and “T-frames” are
related to other standard dimensions that are not a part of the “frame number” designation, and
certainly not the “frame number series” designation. There is another way to handle motors with
dimensions and construction characteristics that deviate from the standard T-frame, or U-frame,
dimensions. NEMA will cover those in comments on the particular issues on which DOE
requested comment.
To provide for complete and clear definitions of the new types of electric motors which may be
covered by efficiency standards NEMA proposes the following for consideration by DOE [Note –
the number of poles and output power level are defined as part of the “rating” in the definition of
“basic model” in §431.12, so such are not included as a part of the definitions of types of
“electric motors” proposed in the following]:
 Add a definition of “motor” as “motor means a machine that converts electrical power
into rotational mechanical power.”
 Change the definition of “electric motor” to be “Electric motor means a motor that:
(1) Is a single-speed, induction motor;
(2) Is rated for continuous duty (MG1) operation or for duty type S1 (IEC);
(3) Contains a squirrel-cage (MG1) or cage (IEC) rotor;
(4) (i)Is built in accordance with NEMA T-frame dimensions or their IEC metric
equivalents, including a NEMA frame size that is between two consecutive NEMA Tframes or their IEC metric equivalents; or
(ii) Is built in an enclosed 56 NEMA frame size (or IEC metric equivalent);
(5) Has performance in accordance with NEMA Design A (MG1) or B (MG1)
characteristics or equivalent designs such as IEC Design N (IEC); and
(6) Operates on polyphase alternating current 60-hertz sinusoidal power.
2

No change is required in the definition of “General purpose electric motor”.

Change the definition of “general purpose electric motor (subtype I)” to “General purpose
electric motor (subtype I) means a general purpose electric motor that:
(1) Has foot-mounting that may include foot-mounting with flanges or detachable feet;
(2) (i) Is rated at 230 or 460 volts (or both) including motors rated at multiple voltages
that include 230 or 460 volts (or both), or
(ii) Can be operated on 230 or 460 volts (or both); and
(3) Includes, but is not limited to, explosion-proof construction.”
Incorporated by reference in §431.15 (e) (2) (i)
7

No change is required in the definition of “General purpose electric motor (subtype II)”.

Add a definition of “definite purpose electric motor” as “Definite purpose electric motor
means any electric motor that:
(1) Is rated at 600 volts or less; and
(2) Cannot be used in most general purpose applications and is designed either:
(i) To standard ratings with standard operating characteristics or standard mechanical
construction for use under service conditions other than usual, such as those specified in
NEMA MG1– 2009, paragraph 14.3, ‘‘Unusual Service Conditions,’’ (incorporated by
reference, see §431.15); or
(ii) For use on a particular type of application.”

Add a definition of “special purpose electric motor” as “Special purpose electric motor
means any electric motor, other than a general purpose electric motor or definite
purpose electric motor, that:
(1) Is rated at 600 volts or less; and
(2) Has special operating characteristics or special mechanical construction, or both,
designed for a particular application.”

As an example of a definition of a new electric motor type, define “Totally enclosed nonventilated (TENV) definite purpose electric motor means a definite purpose electric
motor that is built in a frame-surface cooled, totally enclosed configuration that is
designed and equipped to be cooled only by free convection.”
The above proposal incorporates all of the nine characteristics DOE identified, except for the
two that are a part of the rating. It should be noted that the above proposed definition of
“general purpose electric motor (subtype I)” is the same as in the present §431.12, except that it
would now include electric motors built in an enclosed 56 NEMA frame size (or IEC metric
equivalent), as proposed in the Stakeholders Joint Petition of August 15, 2012.
Similar proposed definitions of other types of definite purpose electric motors and special
purpose electric motors will be provided in the comments where those particular definitions are
discussed.
The above proposal accomplishes the intended goal of providing complete and clear definitions
in §431.12 of all of the types of electric motors for which standards may be established by DOE.
3) Types Of Motors For Which DOE Does Not Intend To Establish Efficiency Standards:
DOE has indicated that definitions are being proposed for certain types of electric motors for
which efficiency standards may not be proposed, but feels it is necessary to provide the
definitions where there may be confusion with a covered electric motor of somewhat similar
construction. NEMA does not agree that such definitions are necessary. If the definition of a
covered electric motor is properly complete and clear then there should be no confusion with a
motor that is not of the same construction or performance. It also makes it unnecessary that
DOE establish definitions for all types of motors of similar basic construction or performance,
but differ in some characteristic as to be exempt. For example, in the proposed list of definitions
in the NOPR DOE has omitted some types of motors DOE identified in the 1997 Policies
statement as also being exempt. Why DOE picked the particular types of exempted motors to
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include when proposing definitions for exempted motors in the NOPR and not the others is
confusing. Further, so long as standards are clearly identified as applicable to specific defined
types of general purpose electric motors, definite purpose electric motors, or special purpose
electric motors then there is no need to create confusion by defining other types. This also
prevents confusion where DOE refers only to the more general terms “general purpose electric
motors”, “definite purpose electric motors”, or “special purpose electric motors”, but only
intending to refer to specific types covered by standards.
In the case of types of motors for which DOE does not agree with NEMA and would still intend
to explicitly provide exemption from the standards while being of the opinion that definitions are
needed, then NEMA proposes that the definitions be relative to “motors” and not “electric
motors” as it is not necessary that such exempted motors have the additional characteristics of
“electric motors” in order to be exempt. This will also make it easier to identify the pertinence of
any general references to “electric motors” as in the proposed changes to Appendix B to
Subpart B. Such concerns are the basis for NEMA proposing in (2) to include a definition of
“motor” in 10 CFR Part 431. If DOE agrees that a definition of “motor“ is not needed because
reference to such are not needed then the content of the definition can be incorporated in the
definition of “electric motor” as it is incorporated in the present definition.
4) IEC IP (Degrees of Protection) and IC (Methods of Cooling) Classification Codes
IEC motors generally do not use the identifiers, such as TENV, for motor types as defined in
NEMA MG1, some of which are being proposed in the NOPR for inclusion in §431.12. IEC
motors types are identified by the use of IP (classification of protection) and IC (classification of
method of cooling) codes. To properly include IEC equivalent electric motors DOE should
include the proper IEC IP and IC codes within the definitions or as a part of the term being
defined.
IP codes consist of the letters “IP” followed by two characteristic numerals, such as “IPXX”. The
first characteristic numeral describes the degree of protection provided by the enclosure with
respect to persons and also to the parts of the motor inside the enclosure. The second
characteristic numeral describes the degree of protection provided by the enclosure with respect
to harmful effects due to ingress of water. The relative degrees of protection indicated by the
numerical values are given in IEC 60034-5 or Part 5 of NEMA MG1. It should be noted that
when a numeral is provided relative to the general identification of a particular motor design type
that the numeral designates the lowest level of protection applicable to that identification.
Greater levels of protection indicated by higher numeral values can also apply. For example,
the lowest level of protection for enclosed motors is generally considered to be “IP4X”, where
the “X” designates that the degree of protection against ingress of water can be specified as any
applicable level. Motors with codes of “IP5X” and “IP6X”, with each indicating a progressively
higher level of protection, can also be identified as being enclosed motors.
IC codes consists of the letters “IC” followed by a numeral designating the circuit arrangement,
a letter designating the primary coolant type, a numeral designating the method of movement of
the primary coolant, a letter designating the secondary coolant type (if applicable), and a
numeral designating the method of movement of the secondary coolant. Each letter designating
the type of coolant may be omitted if the type is air. Each numeral for the IC codes represents a
specific type of circuit arrangement or method of movement of the cooling medium. The relative
methods of cooling indicated by the numerical values and letters are given in IEC 60034-6 or
Part 6 of NEMA MG1.
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5) Expansion of the Application of Test Procedures Beyond Products Covered by Efficiency
Standards:
DOE has proposed adding a Note to Appendix B to Subpart B that expands the requirement of
the use the test procedures in Appendix B to motor types not covered by energy conservation
standards. NEMA has identified the following concerns with the proposal:

The proposed Note refers to “any representation” made related to special and definite
purpose motor types. The meaning of “representation” is not defined. For the purpose
of these comments NEMA assumes that what is intended is “represented nominal fullload efficiency” (§431.17), given that the purpose of the test procedures is for the
determination of efficiency. This needs to be clarified if the Note is to be adopted.

The proposed Note refers to special and definite purpose motor types for which
definitions are provided at §431.12. The only definitions for those motor types are the
present very general definitions of “definite purpose motor” and “special purpose motor”.
None of the definitions proposed in the NOPR for §431.12 are identified as being for a
“definite purpose motor” type or “special purpose motor” type. The Note then appears to
apply to all ““definite purpose motors” and “special purpose motors”, including direct
current, single-phase, polyphase, TENV, air-over, submersible, etc. Yet, the test
procedures in Appendix B obviously do not apply to many of those types. This needs to
be clarified in any final version of the Note that may be included in a Final Rule.

The proposed Note requires the test procedure in Appendix B to be followed for any type
of “definite purpose motor” and “special purpose motor” that DOE provides definitions in
§431.12. Assuming that DOE corrects the proposed definitions to refer to the proper
“definite purpose motor” and “special purpose motor” types then some of the definitions
DOE is proposing are for the purpose of exempting specific “definite purpose motor” and
“special purpose motor” types. Part of the reason for exemption is that the test
procedures in §431.12 are not applicable. The Note needs to be modified to correctly
identify specifically what types of “definite purpose motors” and “special purpose motors”
defined in §431.12 the Note applies to if the Note is included in a Final Rule.

The proposed Note requires the applicable test procedure in Appendix B be followed for
any “definite purpose motor” and “special purpose motor” type defined in §431.12 for
which a representation (of efficiency) is to be made. This appears to extend the
application of the test procedures to any motor that meets a definition of one of the types
of “definite purpose motor” and “special purpose motor” even if no energy conservation
standard has been established. For example, given the proposed very general definition
of TENV motor that DOE has proposed this would make it mandatory that the test
procedures in Appendix B be followed for any motor of TENV construction, regardless of
electrical design, performance or rating. Yet, the test procedures are for TENV motors
of only specific design. It is not clear why DOE would expect a manufacturer of a motor
that fits one of the definitions, but is outside of the range of ratings of the standards to
follow Part 431 requirements for that motor. To minimize confusion, the test procedures
should be applicable only to those general purpose, definite purpose and special
purpose electric motors for which energy conservation standards apply.
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
In the proposed Note the purpose of stating “or for which specific testing procedures are
provided in this appendix,” is not clear. The first part of the sentence already makes it a
requirement that the applicable test procedure be followed for any defined type of
“definite purpose motor” and “special purpose motor”. The “or” provision infers that the
test procedures must be followed for some type of motor that is not defined in §431.12,
but for which test procedures have been established. This is confusing, if that is the
case.

The proposed Note refers to “special and definite purpose motor types”. The test
procedures are for types of “special and definite purpose electric motors”. The proposed
definitions in the NOPR are for types of “electric motors”, not “motors”. The Note should
be changed to refer to “special and definite purpose electric motors”.

The proposed Note appears to be in conflict with §431.17. The proposed Note states
that “any representation made ... related to special and definite purpose motor types …
must be based upon results generated under this test procedure.” This requires that
efficiency be determined by test for all designs of such motor types. Similarly, the Note
states that “any representation, including demonstrations of compliance, related to
general purpose electric motors (subtype I or II) … must be based upon results
generated under this test procedure.” This does not permit determination of efficiency
for representation nor compliance using an AEDM or third party certification program as
permitted in §431.17. Continued use of AEDMs and third party certification programs
need to be accepted by DOE for all types of electric motors.

The proposed Note appears to limit the use of Appendix B to Subpart B for the purposes
related to representation (of efficiency) by the manufacturer and for the purpose of
demonstrating compliance. There is no mention of application of the test procedures
relative to any enforcement process, although the process in §431.383 does refer to
Appendix B to Subpart B.

The proposed note states requirements which would be mandatory after a “date 180
days after publication of the final rule”. DOE has indicated that the purpose of this
NOPR and any related subsequent Final Rule is to establish additional test procedures
relevant to particular types of electric motors for which DOE may establish new energy
conservation standards. According to the latest information from DOE on RIN 1904AC28 the target completion date of any Final Rule for possible efficiency standards is
5/00/20143. The date for compliance is not clear at this time, but at a Public Meeting on
August 21, 2012 DOE stated that “any standards that DOE establishes would have a
compliance date no sooner than December 19, 2015.”4 There is no information at
Reginfo.gov relative to RIN 1904-AC89 on DOE work on test procedures for electric
motors and the present NOPR. However, at the Public Meeting held on July 16, 2013
DOE indicated that the projected date for a Final Rule on test procedures is December,
2013. This means that DOE is proposing that the requirements of Appendix B to subpart
B become effective for all defined types of “special and definite purpose motors” more
than 1-1/2 years in advance of the effective date of any standards and compliance
requirements. In the past the “effective date” of the test standards for newly covered
3
See RIN 1904-AC28 at http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=201304&RIN=1904-AC28
Presentation “U.S. Department of Energy Preliminary Analysis Public Meeting About Energy Conservation
Standards for Electric Motors”, August 21, 2012
4
11
types of electric motors has been the date a manufacturer may privately determine as
required to provide sufficient time to conduct the necessary testing to demonstrate
compliance by the effective date of the applicable standards. The same should be true
when adding certain types of special and definite purpose electric motors as newly
covered products. If the proposed Note is included then the effective date should be the
same as that of any efficiency standards which may be established.

The proposed note requires that the prescribed revised test procedures in Appendix B to
Subpart B are to be mandatory 180 days after publication of the Final Rule for any
representation (of efficiency), including demonstration of compliance, for defined definite
purpose (electric) motors, special purpose (electric) motors, and general purpose electric
motors (subtype I or II). Based on the information from DOE this puts the effective date
at some time around June, 2014. Efficiency standards and compliance requirements
based on present test procedures are already in place for several of the types of electric
motors presently defined in §431.12 or for which clarifying definitions are proposed in the
NOPR. The effect of the proposed changes in some of those test procedures is to
require that after approximately June, 2014 the electric motors must be tested in such a
way that the tested value of total losses will be greater and the tested value of efficiency
be lower than the values that are obtained under the present test procedures that would
be used up until June, 2014. To remain in compliance with the existing standards after
the effective date the manufacturer would be required to redesign the electric motors
that presently are in compliance solely because of a change in the test procedures.
DOE could provide remedy for that through a change in the standards, as done for other
covered products when changes in the test procedure adversely affected the tested
efficiency, but the present proposed effective date for any modification of standards is
not earlier than December, 2015. In essence, the proposed changes in the test
procedures for various types of presently covered electric motors is equivalent to a
hidden change in the efficiency standards. The effective date of any change in test
procedures should be coincident with the effective date of any remedial change in the
standards provided to rectify the effect of the changes in the test procedures on the
tested efficiency.

The proposed Note sets forth compliance dates and specific requirements for “special
and definite purpose motor types for which definitions are provided at §431.12” and for
“general purpose electric motors (subtype I or II)” regardless of any other provisions in
Part 431. Yet, according to §431.17(a)(1) the test procedures in Appendix B to Subpart
B are invoked through §431.16 only when “the average full load efficiency of each basic
model of electric motor” is to be determined by test. Burying provisional requirements
relevant to “representation” and “compliance” of all electric motors in an Appendix that
applies to only a selected group of electric motors can lead to unnecessary confusion.
Any such provisional requirements included in the Final Rule should be within the
appropriate requirements in §431.16 or §431.17.
12
Issues on Which DOE Seeks Comment: Although DOE welcomes comments on any
aspect of this proposal, DOE is particularly interested in receiving comments and views
of interested parties concerning the following issues:
1. DOE requests comment on the decision to incorporate definitions for NEMA Design A
and NEMA Design C motors based on the NEMA MG1–2009 definitions of these motor
designs.
NEMA Comment – NEMA acknowledges that there is an error in the definition of Design C in
MG1-19.1.3 that DOE has copied for the proposed definition. In reference to the level of locked
rotor torque and breakdown torque the statements of “up to the values” should be “not less than
the values” as the limits in the referenced tables are minimum values. The proper statements
are found in the actual standards in the referenced clauses of MG1-12.37 and MG1-12.39.
2. DOE requests comment on the proposed definitions for IEC Design N and H motors.
NEMA Comment - The parenthetical statement “(as demonstrated by the motor’s ability to
operate without an inverter)” is unnecessary and confusing and should be removed. Such a
statement is not included in the present definition of NEMA Design B motor nor in the proposed
definitions of NEMA Designs A and C motors.
While the definitions of the Design N and H types in IEC 60034-12 refer to the range of 0.4 kW
to 1600 kW, the definitions as incorporated in 10 CFR should be within the range DOE has
identified as applicable to all defined electric motors. That range is 0.75 kW to 373 kW as in the
present §431.25 of 10 CFR.
In various definitions DOE includes IEC standards in terms of the level of equivalency to the
NEMA MG1 standard which are used as the basis of the definitions. DOE should be aware that
depending on the level of apparent locked rotor power an IEC Design N electric motor may be
equivalent to a NEMA Design B electric motor or to a NEMA Design A electric motor.
Depending on the level of apparent locked rotor power an IEC Design H motor may be
equivalent to a NEMA Design C electric motor or may not be equivalent to any NEMA Design
type.
DOE should be aware that at the present time the marking requirements in IEC 60034-1 do not
require that a Design type or locked rotor apparent power be marked on IEC design motors.
3. DOE seeks comment on its proposed definition for electric motors with moisture
resistant windings and electric motors with sealed windings and its preliminary decision
to not propose additional testing instructions for these motors types.
NEMA Comment – The proposed definitions refer to NEMA MG1-2009, paragraphs 12.62 and
12.63 as incorporated by reference in §431.15. The present §431.15 does not include 12.62 or
12.63 and this NOPR does not include any proposed changes to §431.15.
If DOE does establish standards for such motors then in accordance with the DOE 1997
Policies Statement and proposed changes to Appendix B of Subpart B the definition should be
for that of a “special purpose electric motor with moisture resistant windings”. If DOE does not
establish standards then the definition should be for that of a “special purpose motor with
13
moisture resistant windings”, however it is preferred that in such case no definition be
established as a definition is not necessary since the 1997 Policies statement is sufficient.
In the proposed definitions DOE uses the term “engineered for passing”, rather than “capable of
passing” as stated in the NEMA MG1-2009 standard. Something might be “engineered for” the
purpose of passing some type of test, but it does not necessarily mean that the engineering will
result in a product that successfully passes the test. It is not clear if “demonstrated” then refers
to demonstration of the engineering procedure or the testing of the actual product. NEMA
prefers the term “capable of passing” as a clearer statement that the actual product can and has
been shown to pass the test on a representative unit.
As explained in the Executive Summary above the proposed definition is inadequate as it is
neither sufficiently complete nor clear. Assuming that the revisions to the definitions as
described in the Executive Summary are made then NEMA proposes that a proper definition
based on paragraph 1.27.1 of NEMA MG1-2009 would be:
“Special purpose electric motor with moisture resistant windings means a special purpose
electric motor that has motor windings that have been treated such that exposure to a moist
atmosphere will not readily cause malfunction. This type of machine is intended for exposure to
moisture conditions that are more excessive than the usual insulation system can withstand. A
motor with moisture resistant windings is capable of passing the conformance test for moisture
resistance described in NEMA MG1-2009, paragraph 12. 63, (incorporated by reference, see
§431.15) as demonstrated on a representative sample or prototype.”
The above comments are also applicable to the proposal to define “electric motor with sealed
windings”. In this case, if DOE establishes a definition it should be for a “special purpose
electric motor with sealed windings” and based on paragraph 1.27.2 of NEMA MG1-2009 NEMA
proposes that the definition be:
“Special purpose electric motor with sealed windings means a special purpose electric motor
that has an insulation system which, through the use of materials, processes, or a combination
of materials and processes, results in windings and connections that are sealed against
contaminants. This type of machine is intended for environmental conditions that are more
severe than the usual insulation system can withstand. A motor with sealed windings is capable
of passing the conformance test for water resistance described in NEMA MG1-2009, paragraph
12. 62, (incorporated by reference, see §431.15) as demonstrated on a representative sample
or prototype.”
NEMA would like to call DOE’s attention to an additional type of special treatment of windings
that is included NEMA MG1-2009, paragraph 12.62. The third type is “special purpose electric
motor with encapsulated windings.” In the 1997 Policies Statement DOE identified this as a
special purpose motor with an electrical modification of encapsulation. A definition of a
“machine with encapsulated windings” was in NEMA MG1 up until the 1993 version when it was
replaced with a “machine with moisture resistant windings”. Derived from that earlier definition,
NEMA proposes that the following definition also be considered for §431.12:
“Special purpose electric motor with encapsulated windings means a special purpose electric
motor that has motor windings that are fully enclosed in an insulating material that protects the
windings from detrimental operating environments (moisture, dust, dirt, contamination, etc.).
The encapsulant material may fully enclose not only the motor windings but the wound stator
core. A motor with encapsulated windings is capable of passing the conformance test for water
14
resistance described in NEMA MG1-2009, paragraph 12. 62, (incorporated by reference, see
§431.15) as demonstrated on a representative sample or prototype.”
If DOE does not include the NEMA recommended revisions to the definition of “electric motor”
and “special purpose electric motor” then the performance and construction characteristics
included in those definitions would need to be included in the definitions of “special purpose
electric motor with moisture resistant windings”, “special purpose electric motor with
encapsulated windings”, and “special purpose electric motor with sealed windings”.
3.A NEMA noted that on page 38463 of the NOPR that “DOE requests any data,
information, or comments regarding the effects of specially insulated stator windings on
electric motor efficiency.”
NEMA Comment - NEMA believes that no different requirements in energy conservation
standards are needed between these types.
4. DOE requests comments on its proposed definition for inverter-capable electric
motors and its decision not to provide any test procedure instructions for this motor
type.
NEMA Comment - As explained in the Executive Summary above the proposed definition is
inadequate as it is neither sufficiently complete nor clear. “Inverter-capable” is a term generally
applied to general purpose motors designed in accordance with Part 12 of NEMA MG1 for
which application guidance for using the motors with inverters is provided in Part 30 of NEMA
MG1. The type of electric motors that Part 30 of NEMA MG1 applies to is the general purpose
electric motor (subtype I) or general purpose electric motor (subtype II), not definite-purpose
electric motors nor special-purpose electric motors. A proper definition would be:
“Inverter-capable electric motor means a general purpose electric motor (subtype I) or general
purpose electric motor (subtype II) that is also capable of continuous operation on an inverter
control over a limited speed range and associated load.”
5. DOE requests comments on its proposed definition and preliminary decision not to
propose any clarifying testing instructions for TENV electric motors.
NEMA Comment - If DOE does establish standards for such motors then in accordance with the
DOE 1997 Policies Statement the definition should be for that of a “Totally enclosed nonventilated (TENV) definite purpose electric motor”. However, if DOE does not establish
standards then the definition should be for that of a “Totally enclosed non-ventilated (TENV)
definite purpose motor”, if it is necessary that any definition be included.
As explained in the Executive Summary above the proposed definition is inadequate as it is
neither sufficiently complete nor clear. Please refer to the more complete and clear proposed
definition of “totally enclosed non-ventilated (TENV) definite purpose electric motor” given in the
example in the Executive Summary. If DOE does not include the NEMA recommended
revisions to the definition of “electric motor” and “definite purpose electric motor” then the
performance and construction characteristics included in those definitions would need to be
included in the definition of “totally enclosed non-ventilated (TENV) definite purpose electric
motor”.
15
Should DOE intend to reference IEC IP and IC codes in the item being defined or in the
definition, NEMA understands that the corresponding codes are IP4X, or higher level of
protection, and IC4A1A0 or IC410. For IP4X the “4” designates that the machine is protected
against solid objects greater than 1mm in diameter and “X” designates that the degree of
protection against the ingress of water can be any value. The first numeral may be greater
than “4” indicating a higher level of protection. IC4A1A0 designates that the circuit arrangement
“4” is for a frame surface cooled machine, the primary or internal coolant type “A” is Air (which
may be omitted in the short version),) the method “1” of moving (i.e., circulating) the interior
cooling air is related to parts on the rotor or shaft which are rotating at the operating speed, the
secondary or external coolant type “A” is Air (which may be omitted in the short version), and
that the method “0” of movement of the secondary exterior cooling air is by free convection.
6. DOE requests comments on its proposed definition of integral brake electric motor
and its preliminary decision to include them in the scope of these test procedures.
NEMA Comment – DOE is proposing the same test procedure for “integral brake electric
motors” and “non-integral brake electric motors”. The location of the brake assembly is then not
of importance in determining the efficiency since the non-electrical losses of the brake assembly
are to be included in the determination. Unless DOE knows of some type of brake motor that is
not of one of the two types then NEMA does not see the need for the two definitions. Instead,
NEMA proposes that a single definition of “special purpose electric motor with brake” be
included as:
“Special purpose electric motor with brake means a special purpose electric motor that
contains a brake mechanism either within the motor enclosure or external to the motor
enclosure.”
NEMA does understand that this would include integral brake electric motors as covered
products, whereas the Stakeholders Joint Petition of 2012 proposed that such motors continue
to be exempted. As explained in the Petition, the test procedure envisioned for motors with
brakes involved the removal of the brake so no losses associated with the brake would be
included in the determination of the efficiency of the motor. Removal of the brake components
of an integral brake motor could leave the motor inoperable, whereas that would not be a
problem with a non-integral brake motor. In this NOPR DOE has proposed that testing is to be
with the components of the brake left in place and that the mechanical losses of the brake be
included in the determination of the overall efficiency. Hence, there is no difference in the test
procedures based on the location of the brake components. NEMA expects that should it be
determined that the mechanical losses of the brake components are significant relative to the
losses of the motor components that any energy conservation standards established for electric
motors tested with the brake components in place will be based on including those additional
brake losses.
If after considering the above comment DOE still sees the need for separate definitions then
NEMA offers the following additional comments relative to the proposed definition of “integral
brake electric motor”.
If DOE does establish standards for such motors then in accordance with the DOE 1997
Policies Statement and proposed changes to Appendix B of Subpart B the definition should be
for that of an “Integral brake special purpose electric motor”. However, if DOE does not
establish standards then the definition should be for that of an “Integral brake special purpose
motor”, if it is necessary that any definition be included.
16
As explained in the Executive Summary above the proposed definition is inadequate as it is
neither sufficiently complete nor clear. Also, “inside of the motor endshield” infers that the brake
fits within the size of the endshield and is mounted within the endshield. This appears to
exempt construction where the brake is within the motor frame between the interior surface of a
endshield and the stator core, but not actually inside the endshield. Assuming that the revisions
to the definitions as described in the Executive Summary are made then a proper definition
would be:
“Integral brake special purpose electric motor means a special purpose electric motor
that contains a brake mechanism either within the motor enclosure or between a motor
fan, when present, and the nearest endshield.”
If DOE does not include the NEMA recommended revisions to the definition of “electric motor”
and “special purpose electric motor” then the performance and construction characteristics
included in those definitions would need to be included in the definition of “integral brake special
purpose electric motor”.
6.A NEMA noted that on page 38468 of the NOPR DOE also requested comments on the
proposed definition of “non-integral brake electric motor”.”
NEMA Comment – Please see the comments under Item (6) regarding the proposed definition
of “integral brake electric motor.” In this case NEMA proposes that the definition, if needed, be
that of a “non-integral brake special purpose electric motor” as:
“Non-integral brake special purpose electric motor means a special purpose electric
motor that contains a brake mechanism outside of the endshield, but not between the
motor fan and endshield.”
If DOE does not include the NEMA recommended revisions to the definition of “electric motor”
and “special purpose electric motor” then the performance and construction characteristics
included in those definitions would need to be included in the definition of “non-integral brake
special purpose electric motor”.
7. DOE requests comments on its preliminary decision to test integral brake electric
motors and non-integral brake electric motors without disassembly but, rather, with their
brake components powered externally.
NEMA Comment – As a part of the test procedures DOE proposes that “(non-)integral brake
electric motors shall be tested with the integral brake component powered by a source separate
from the source powering the electric motor under test.” What does DOE identify as a separate
power source? A test facility is likely to have only one source of power. Besides, this
requirement is not necessary as all that is necessary is that the test equipment used to measure
the electrical power into the motor is connected only to the motor leads and not to both the
motor leads and brake leads. The test procedure should clearly state that the efficiency
determined for the electric motor is not to include any power that may be required to disengage
the brake.
NEMA understands that another reason for separating the connections of the motor and the
brake from the same point of connection to the power supply is that during no load testing the
voltage applied to the motor may be reduced to the point that the brake would not be
17
disengaged if the same level of voltage was applied to the brake. It would be helpful if this is
pointed out in the test procedure by reference to rated voltage.
In addition to providing for disengaging the brake by providing an external source of power, the
test procedure should also provide for manually releasing the brake when such an option is
available.
The proposed test procedure does not actually state that the brake is to be disengaged during
testing.
The proposed test procedure refers to the brake being disengaged from the motor shaft at some
time. The brake does not normally act on the motor shaft as the method of braking. Rather,
brake components are mounted on the shaft and the braking action is between those rotating
components of the brake and stationary brake components.
Why the measurement of any electrical power to the brake is to be taken in 10 minute intervals
is not understood. The rated load heat run portion of the IEEE 112 Method B test does extend
over a long enough period of time that there would be several time intervals 10 minutes in
length during which the power might be recorded. However, the load test and no load test are
normally performed in less than 10 minutes each. No measurement of the power to the brake
would be required during that testing. It should be sufficient to include a record of the input
power to the brake when measurements are recorded for the electric motor during the Method B
test procedure.
If the NEMA proposal that separate definitions are not needed for “integral brake special
purpose electric motor” and “non-integral brake special purpose electric motor” is accepted by
DOE then only a single test procedure for “special purpose electric motor with brake” is
required. In this case, NEMA proposes:
“4.4 Special Purpose Electric Motors with Brakes:
For a special purpose electric motor with brake the efficiency of the electric motor is to be
determined based on measurements of the electrical input power to just the electric motor and
not include any power which may be supplied to the brake. For designs in which the power
leads for the brake are interconnected with the stator winding or electric motor leads, it will be
necessary to separate that connection. During testing the brake is to be disengaged by either
supplying electrical power to the brake at its rated voltage or through the use of a mechanical
release, when available. When electrical power is supplied to the brake for the purpose of
disengaging the brake the magnitude of required power in watts shall be measured and
recorded during the testing.”
7.A NEMA notes that on page 38469 of the NOPR and in the proposed revisions to
§431.12 the DOE proposes a definition of “partial electric motor”, but failed to request
comments on the proposed definition.
NEMA Comment – In contrast to the other new definitions for specific types of definite purpose
or special purpose electric motors proposed in the NOPR for which different levels of efficiency
may be established, the term “partial” is used in the industry to refer to what might be
considered to be similar to that of a design element of a motor rather than a complete motor.
“Partial” may refer to an assembly of parts of a general purpose motor, definite purpose motor,
or special purpose motor and not a particular subset of just one of the three types. As such, it
may be best to incorporate the concept of “partial” as a design element within other definitions
18
rather than as a separate type of electric motor. For example, the definition of “electric motor”
that NEMA proposes in the Executive Summary can be modified as:
“Electric motor means a motor that:
(1) Is a single-speed, induction motor;
(2) Is rated for continuous duty (MG1) operation or for duty type S1 (IEC);
(3) Contains a squirrel-cage (MG1) or cage (IEC) rotor;
(4) (i)Is built in accordance with NEMA T-frame dimensions or their IEC metric
equivalents, including a NEMA frame size that is between two consecutive NEMA Tframe sizes or their IEC metric equivalents; or
(ii) Is built in an enclosed 56 NEMA frame size (or IEC metric equivalent);
(5) Has performance in accordance with NEMA Design A (MG1) or B (MG1)
characteristics or equivalent designs such as IEC Design N (IEC);
(6) Operates on polyphase alternating current 60-hertz sinusoidal power; and
(7) Includes, but is not limited to, partial motor construction.”
The definition required to complete this is then that of a “partial motor”, rather than a “partial
electric motor”. In the NOPR DOE used the phrase “engineered for performing” in the proposed
definition. NEMA understands that what is intended is not that engineering was completed for a
particular design, but rather that once the endshields and bearings are installed then the partial
motor becomes a complete motor capable of actual operation. NEMA proposes that the
definition be:
“Partial motor means an assembly of motor components necessitating the addition of no more
than two endshields, including bearings, to create an operable motor. For the purpose of this
definition, the term ‘‘operable motor’’ means a motor capable of operation in accordance with
the applicable nameplate ratings.”
Since in the NEMA proposals the term “electric motor” is a part of all of the definitions of general
purpose motors, definite purpose motors, and special purpose motors then partial motor
assemblies of all of those types are covered by the above proposal.
7.B NEMA notes that on page 38469 DOE requested comments on the proposed test
procedure for “partial electric motors”.
NEMA Comment – The test instructions appear to be structured around the testing provisions in
Subpart U of 10 CFR Part 431 covering enforcement for electric motors, and do not consider
Subpart B which includes testing requirements for certification. The test instructions assume
the “partial motor” is mated to other parts and must be disconnected from other equipment.
Such is not generally the case when testing for certification. As shipped from a motor
manufacturer the “partial motor” may not be mated to anything. The mating of the “partial
motor” with other parts may be done by a different manufacturer to manufacture a complete
assembly. This raises an issue that DOE has not addressed. Is the manufacturer of the partial
electric motor considered to be the entity which manufactures the non-functional partial motor or
the entity which uses the partial motor to manufacture a complete functional assembly, such as
an integral gear motor as DOE identified on page 38468 of the NOPR? What about importation
where the importer is considered to be the manufacturer?
In the test instructions DOE has also proposed that “if an endshield is necessary, an endshield
meeting NEMA or IEC specifications shall be obtained through the manufacturer, either by
request or purchased as a replacement part.” This presumes that the manufacturer of the
19
partial electric motor has endshields of the appropriate designs available or can make such
available. This may not be the case. If the manufacturer is considered to be the entity which
manufactures only the “partial electric motor” parts of a complete electric motor, then that
manufacturer may not manufacture complete motors based on the “partial electric motor”. If the
manufacturer is considered to be the entity which uses the “partial electric motor” to
manufacture an assembly that DOE considers to be a type of “electric motor”, such as integral
gear motor, then that manufacturer is not likely to have designs available for the required
endshields. In the case of imported equipment, the importer is designated as the manufacturer.
It is unlikely that the importer could provide the required endshields. In such cases the
manufacturer should not be required to provide endshields which the manufacturer does not
normally produce, use, nor could not easily obtain. Instead of the manufacturer being required
to provide the endshields, the manufacturer should be given the option to provide the
endshields, if possible. If the manufacturer declines to do so and instead agrees to let the test
laboratory provide the endshields, the test laboratory shall consult with the manufacturer in
order to determine the critical characteristics the test endshields must possess. It is then the
responsibility of the test laboratory to provide the endshields.
8. DOE requests comments concerning its proposed definition for immersible electric
motor, especially with regards to differentiating this motor type from liquid-cooled
electric and submersible electric motors.
NEMA Comment - If DOE does establish standards for immersible electric motors then in
accordance with the DOE 1997 Policies Statement and proposed changes to Appendix B of
Subpart B the definition should be for that of an “immersible definite purpose electric motor”.
However, if DOE does not establish standards then the definition should be for that of an
“immersible definite purpose motor”.
According to the DOE analysis, immersible definite purpose electric motors may be designed for
operation while submerged in liquid or may be designed to prevent operation while submerged.
This should be included in the definition.
As explained in the Executive Summary above the proposed definition is inadequate as it is
neither sufficiently complete nor clear. Assuming that the revisions to the definitions as
described in the Executive Summary are made then a proper definition would be:
“Immersible definite purpose electric motor means a definite purpose electric motor that
is primarily designed to operate continuously in free-air, but is also capable of
withstanding complete immersion in liquid for a continuous period of no less than 30
minutes, during which time any operation may or may not be inhibited.”
If DOE does not include the NEMA recommended revisions to the definition of “electric motor”
and “definite purpose electric motor” then the performance and construction characteristics
included in those definitions would need to be included in the definition of “immersible definite
purpose electric motor”.
The definition proposed above is sufficiently clear that those knowledgeable in the application of
motors would not purposely use an immersible definite purpose electric motor in an application
where a submersible motor is required. In fact, many immersible motors contain a mechanism
for preventing the operation of the motor when immersed in liquid. The reverse is also true.
Those knowledgeable in the application of an immersible definite purpose electric motor which
operates primarily in air would not purposely use a submersible motor, which must be
20
submerged in liquid, as a substitute. Similarly, it is obvious to the knowledgeable user that there
is no provision in the immersible definite purpose electric motor for providing any cooling liquid
directly to the electric motor. Nor would the typical application for an immersible definite
purpose electric motor have provisions for providing a source of liquid for cooling. The definition
of “immersible definite purpose electric motor” does not require a definition of “submersible
definite purpose electric motor” nor “liquid-cooled definite purpose electric motor” in order to
properly identify when a particular design of electric motor is an “immersible definite purpose
electric motor”.
Should DOE intend to reference IEC IP and IC codes in the item being defined or in the
definition, NEMA understands that the corresponding codes are IP67 and IC4A1A0 or IC41A0.
For IP67 the “6” designates that the machine is dust tight and “7” designates that the machine is
protected against the effects of immersion. IC4A1A0 designates that the circuit arrangement
“4” is for a frame surface cooled machine, the primary or internal coolant “A” is Air (which may
be omitted in the short version), the method “1” of moving (i.e., circulating) the interior cooling
air is related to parts on the rotor or shaft which are rotating at the operating speed, the
secondary or exterior coolant “A” is Air, and that the method “0” of movement of the secondary
exterior cooling air is by free convection, or conduction in this case.
9. DOE invites comment on its proposed test procedure instructions for immersible
electric motors, in particular, the proposal to allow for a maximum run-in period of 10
hours prior to testing according to IEEE Standard 112 Test Method B.
NEMA Comment – The tests described on pages 38465 and 38466 and summarized in Table
III-2 of the NOPR which DOE had performed on a sample immersible motor clearly indicate the
difference in efficiency when testing the immersible motor as received for testing, after an
extended time of operation, and with the seals removed. After an extended total run time of 10
hours it appears that the total losses reported for Test 3 had decreased by 14 watts or 3% from
that for Test 1 based on normal testing as received. With the seals removed the total losses
reported for Test 2 decreased by 97 watts or 21% from that for Test 1. Based on this
information the losses attributed to the seals might appear to have decreased by 14 watts
during the total time for testing. In fact, it is likely that the losses attributed to the seals at the
time of receipt of the immersible motor was higher than 97 watts and decreased by more than
14 watts during the 10 hours of testing because the efficiency (as related to the total losses) of
Test 1 should have been determined after an extended operating time because it is a
requirement of IEEE 112 Test Method B that a rated load heat run be performed before the load
test and no load test that are used to determine the efficiency. If the losses attributed to the
seals decreased as a result of the running time between Test 1 and Test 3, which may have
been less than 8 of the total 10 hours, then the losses must have also decreased between the
time the immersible motor was first energized and the end of Test 1. What the true decrease in
seal losses for 10 hours of running time was is unknown from the information provided in the
NOPR. But, the testing does illustrate the difficulty of determining the efficiency of electric
motors relative to operating time with various types of seals.
The results also indicate that for the tested immersible motor the initial losses in the seals were
of sufficient magnitude to reduce the efficiency by 3 NEMA bands below that with the seals not
installed. Requiring electric motors with seals installed to meet the same efficiency level as
when seals are not installed would be a de-facto increase in the efficiency standards for
ordinary electric motors that will be difficult to achieve. For example, for the tested immersible
motor if the efficiency with the seals installed was required to be the same 91.0% then the
efficiency of the immersible motor without the seals installed would need to be at least 93.2%.
21
That is an increase of 4 NEMA bands. The highest level of efficiency that DOE determined as
possible for the 5 hp motors used as representative units in its study during this rulemaking was
91.7%5 when using advanced technology components, some of which are not available in the
U.S. at this time.
Seals are sized according to the diameter of the shaft. The same design of contact seal may be
used on all motors of the same NEMA frame number series. Assuming that the motor that DOE
tested was in the standard 182 frame number, or 180 frame number series, for a 5 horsepower
2 pole motor (see Part 13 of NEMA MG1-2009), then for a 4 pole motor the rating would be 3
hp. It is expected that the 97 watts of loss measured at near 3600 RPM would be approximately
65 watts at speeds near 1800 RPM. Per §431.25 of 10 CFR the required efficiency level of
general purpose electric motors (subtype I) rated 3 horsepower and 4 poles is 89.5%. To meet
that same efficiency level after seals are installed then the test motor would have to have an
efficiency level of not less than 91.9%, or a reduction in total motors losses, not including seal
losses, of 25% compared to the total losses at 89.5%. The same seal would also be used on
the standard ratings in the corresponding 184 frame number. With the standard rating for a 184
frame higher than that for a 182 frame then the percentage loss would be different. Also,
contact seals of other types than DOE tested would be expected to exhibit different levels of
losses. It should be obvious from the testing that DOE performed and application of the results
to all electric motors that it will difficult to establish energy conservation standards across the
range of electric motors rated from 1 to 500 hp and 2, 4, 6, and 8 poles based on including seal
losses. The only common factor across that range of electric motors is to test for compliance
with energy conservation standards with contact seals removed as permitted today in
accordance with the 1997 Policies Statement.
It should also be noted that some applications require that motors be provided with sealed
bearings. Similar to contact seals, the seals in the bearings introduce additional losses into the
motor. In Appendix B of the Stakeholders Joint Petition it is noted that the seals should be
removed prior to efficiency testing. Rather than remove the seals from the sealed bearing,
NEMA recommends that the sealed bearing be replaced with a standard bearing for testing.
On page 38466 of the NOPR refers to 200 hours as the possible time during which the losses in
seals will continue to decrease. No other information is provided and NEMA does not know the
source of such information in order to comment on its validity. Presumably such a time would
be dependent on the type of contact seal. Even assuming 200 hours would seem to be a short
time basis for a continuous duty electric motor which DOE assumes has an average mechanical
lifetime of up to 108,398 hours6 or an average annual operating time of up to 7,528 hours7. An
assumption that the efficiency level of the electric motor with seals when averaged over the total
period of use would be represented by a run-in time of only 10 hours does not appear to be well
supported by any evidence.
5
Table 5.5 of “PRELIMINARY TECHNICAL SUPPORT DOCUMENT: ENERGY EFFICIENCY PROGRAM
FOR COMMERCIAL EQUIPMENT: ENERGY CONSERVATION STANDARDS FOR ELECTRIC MOTORS”,
U.S. Department of Energy, July 23, 2012.
6
Section 8.2.3 of “PRELIMINARY TECHNICAL SUPPORT DOCUMENT: ENERGY EFFICIENCY PROGRAM
FOR COMMERCIAL EQUIPMENT: ENERGY CONSERVATION STANDARDS FOR ELECTRIC MOTORS”,
U.S. Department of Energy, July 23, 2012.
7
Table 7.2.7 of “PRELIMINARY TECHNICAL SUPPORT DOCUMENT: ENERGY EFFICIENCY PROGRAM
FOR COMMERCIAL EQUIPMENT: ENERGY CONSERVATION STANDARDS FOR ELECTRIC MOTORS”,
U.S. Department of Energy, July 23, 2012.
22
Many testing facilities operate on a standard 8 hour workday. To conduct a run-in for 10 hours
can place a hardship on the testing facility or require running the test in an unmonitored
condition. If the run-in could be completed within 1 day, that may require the actual IEEE 112
testing to be performed on a following day. That would require some time for reheating the
motor before the IEEE 112 test can be performed. DOE does not indicate if the run-in testing is
to be performed with the motor unloaded or at rated load. Presumably the temperature of the
motor in the region of the seals would have an impact on any change in the seal losses during
operation. All of this testing increases the burden on the test facility which needs to provide the
time required to perform the tests as well as the energy for the test motor and all test
equipment. The testing may need to be duplicated if more than one type of seal is used with the
same design of electric motor as required by the application.
NEMA continues to recommend that contact seals be removed prior to testing. If this is not
permitted then it is obvious that efficiency standards for electric motors with contact seals or
sealed bearings would need to be lower than those for the motors without contact seals or
sealed bearings and different levels of standards may be indicated for different types of contact
seals and sealed bearings.
It should also be noted that the title of the proposed 4.3 in Appendix B to Subpart B is
“Immersible Electric Motors and Electric Motors with Contact Seals”. The actual test procedure
appears to describe only the test procedure for immersible electric motors.
Also DOE proposes that “a manufacturer or test laboratory may run the electric motor being
tested for a period of no more than 10 hours in order to break in the contact seals prior to
testing.” First, it is not clear why the “manufacturer” is included in the test procedure. Does that
mean that any time during which the manufacturer may have operated the motor before
shipment would have to be included? How is the test laboratory to know how many hours the
manufacturer may have operated the electric motor? Second, it is presumed that the 10 hours
is not a part of the “testing” (although it seems to be a part of a test procedure) and is before
any part of the IEEE 112 Method B test is performed. The first part of the IEEE 112 test is to
perform a rated load heat run that can take up to several hours to perform. A heat run may also
be conducted at service factor load as a part of the testing for purposes other than efficiency
determination. It is not clear if DOE is intending to limit the total time before actual load testing
to 10 hours, which would include the time for any heat runs, or to the start of the complete IEEE
112 Method B test procedure. Testing with contact seals removed or sealed bearings replaced
with standard bearings eliminates such complexity from the test procedure.
9.A NEMA notes that on page 38466 of the NOPR “DOE requests comment on the
appropriateness of allowing manufacturers to use an alternative power source to run the blower
motor while testing an immersible motor built in a TEBC frame.”
NEMA Comment - As a part of the test procedure DOE also proposes “for immersible motors
built in a totally enclosed blower cooled construction, the smaller, cooling motor shall be
powered by a source separate from the source powering the electric motor under test.” What
does DOE identify as a separate power source? A test facility is likely to have only one source
of power. Besides, this requirement is not necessary as all that is necessary is that the test
equipment used to measure the electrical power into the motor is connected only to the motor
leads and not to both the motor leads and blower leads. As in the case of testing motors with
brakes installed, the proper voltage should be applied to the blower when the voltage to the
motor is to be reduced as a part of the IEEE 112 Method B or Method E test procedure. (See
23
NEMA Comments under Item 7.) It is also not clear why this requirement of not including the
input power to the blower in the measurement of the motor power be applicable only to blower
cooled “immersible” motors, if it is intended that the test procedure is applicable to any electric
motor with contact seals. The test procedure should also clearly state that the input power to
the separately powered blower is not to be included in the determination of the efficiency of the
immersible definite purpose electric motor, or, in general, for any electric motor with a
separately powered blower furnished as a part of the total assembly.
10. DOE requests comment on its preliminary decision not to propose a definition for
electric motors with nonstandard endshields or bases
NEMA Comment – NEMA agrees that a definition should not be created for electric motors with
nonstandard endshields or bases. However, the 1997 Policies statement exempts such
construction on the basis of being used for special purpose motors or for motors outside the
scope of electric motors. Based on this history of interpretation, the present definitions in
§431.12 and the proposed definitions in the NOPR also do not appear to include such
construction. In the context of EISA of 2007 NEMA recommends that such construction be
recognized as a design element applicable to general purpose electric motors, definite purpose
electric motors, and special purpose electric motors. This can incorporated in the definition of
electric motor that NEMA proposes in the Executive Summary as:
“Electric motor means a motor that:
(1) Is a single-speed, induction motor;
(2) Is rated for continuous duty (MG1) operation or for duty type S1 (IEC);
(3) Contains a squirrel-cage (MG1) or cage (IEC) rotor;
(4) (i)Is built in accordance with NEMA T-frame dimensions or their IEC metric
equivalents, including a NEMA frame size that is between two consecutive NEMA Tframe sizes or their IEC metric equivalents; or
(ii) Is built in an enclosed 56 NEMA frame size (or IEC metric equivalent);
(5) Has performance in accordance with NEMA Design A (MG1) or B (MG1)
characteristics or equivalent designs such as IEC Design N (IEC);
(6) Operates on polyphase alternating current 60-hertz sinusoidal power; and
(7) Includes, but is not limited to, construction utilizing special endshields or bases or
both.”
Since in the NEMA proposals the term “electric motor” is a part of all of the definitions of general
purpose motors, definite purpose motors, and special purpose motors then electric motor
assemblies of all of those types with special endshields or bases are covered by the above
proposal.
11. DOE invites comment on its proposed instructions for testing electric motors with
non-standard endshields or flanges.
NEMA Comment - In the test instructions DOE has proposed that if replacement of an endshield
or flange is required, “the replacement endshield or flange shall be obtained through the
manufacturer, either by request or purchased as a replacement part; any such replacement
endshield or flange must be constructed of the same material as the original endplate.” This
presumes that the manufacturer of the electric motor has endshields of the appropriate designs
available or can make such available. This may not be the case. The only design of electric
motor of the particular size that the manufacturer might produce may be only that with the
special endshield or flange. In the case of imported equipment, the importer is designated as
24
the manufacturer. It is unlikely that the importer could provide the required endshield or flange.
In such cases the manufacturer should not be required to provide endshields which the
manufacturer does not normally produce, use, nor could not easily obtain.
It may not be possible to obtain a replacement endshield or flange of the same material,
particularly if the special endshield or flange is made of special material.
Replacement with standard dimension endshields may also require different shaft construction
which would require a complete new assembly of shaft and rotor. For example, a different rotor
assembly is used in an IEC flange motor than in a pinion gear flange assembly.
It may not be necessary that the special endshield or flange be replaced with one of standard
dimensions, if some other design can be used with the test equipment.
The DOE should be aware that a mixture of the terms “endplate” and “endshield” are used in the
proposed test procedure. NEMA assumes both refer to the same part.
NEMA recommends the proposed test procedure be modified as:
“If it is not possible to connect the electric motor to a dynamometer with the non-standard
endshield or flange in place, the testing laboratory shall replace the non-standard endshield or
flange with an endshield or flange of acceptable design. It may be preferred that the
replacement endshield or flange meet the applicable specifications found in NEMA MG–1
(2009) in Section I, Part 4, paragraphs 4.1, 4.2.1, 4.2.2, 4.4.1, 4.4.2, 4.4.4, 4.4.5, and 4.4.6,
Figures 4–1, 4–2, 4–3, 4–4, and 4–5, and Table 4–2 (incorporated by reference, see §431.15)
or the IEC specifications found in IEC 60072–1 (1991) (incorporated by reference, see
§431.15). The manufacturer should be contacted to determine if an appropriate replacement
endshield or flange is available. If not, then before having a replacement constructed the testing
laboratory shall consult with the manufacturer regarding the design of a replacement, including
the type of material used for making the replacement. As an alternative, a general purpose
electric motor of equivalent electrical design and enclosure may be tested instead.”
12. DOE seeks comment on the decision to not propose a definition for electric motors
with non-standard shaft dimensions or additions.
NEMA Comment – NEMA agrees that a definition should not be created for electric motors with
nonstandard shaft dimensions or additions. However, the 1997 Policies statement exempts
such construction. Based on this history of interpretation, the present definitions in §431.12 and
the proposed definitions in the NOPR also do not appear to include such construction.
NEMA does not understand the DOE reference to “additions” with regards to shafts. NEMA
suggests that “non-standard design” may be suitable to cover whatever DOE may be referring
to.
In the context of EISA of 2007 NEMA recommends that such construction be recognized as a
design element applicable to general purpose electric motors, definite purpose electric motors,
and special purpose electric motors. This can incorporated in the definition of electric motor that
NEMA proposes in the Executive Summary as:
“Electric motor means a motor that:
(1) Is a single-speed, induction motor;
25
(2) Is rated for continuous duty (MG1) operation or for duty type S1 (IEC);
(3) Contains a squirrel-cage (MG1) or cage (IEC) rotor;
(4) (i)Is built in accordance with NEMA T-frame dimensions or their IEC metric
equivalents, including a NEMA frame size that is between two consecutive NEMA Tframe sizes or their IEC metric equivalents; or
(ii) Is built in an enclosed 56 NEMA frame size (or IEC metric equivalent);
(5) Has performance in accordance with NEMA Design A (MG1) or B (MG1)
characteristics or equivalent designs such as IEC Design N (IEC);
(6) Operates on polyphase alternating current 60-hertz sinusoidal power; and
(7) Includes, but is not limited to, construction incorporating shafts of non-standard
dimensions or design”
Since in the NEMA proposals the term “electric motor” is a part of all of the definitions of general
purpose motors, definite purpose motors, and special purpose motors then electric motor
assemblies of all of those types with shaft of non-standard dimensions or design are covered by
the above proposal.
13. DOE requests comment on it proposed instructions for testing motors with nonstandard shaft dimensions or additions.
NEMA Comment – As commented on in the proposed definition, NEMA suggests that the words
“additions” be replaced with “non-standard design”.
14. DOE seeks comment regarding its decision not to propose a definition for electric
motors with non-standard base, feet, or mounting configurations.
NEMA Comment – The NEMA comments under Item (10) regarding non-standard bases is
applicable here also. NEMA generally considers “feet” to be a part of a “base”. If DOE sees a
need to expand beyond the proposal in the NEMA comments to Item (10) then NEMA
recommends:
“Electric motor means a motor that:
(1) Is a single-speed, induction motor;
(2) Is rated for continuous duty (MG1) operation or for duty type S1 (IEC);
(3) Contains a squirrel-cage (MG1) or cage (IEC) rotor;
(4) (i)Is built in accordance with NEMA T-frame dimensions or their IEC metric
equivalents, including a NEMA frame size that is between two consecutive NEMA Tframe sizes or their IEC metric equivalents; or
(ii) Is built in an enclosed 56 NEMA frame size (or IEC metric equivalent);
(5) Has performance in accordance with NEMA Design A (MG1) or B (MG1)
characteristics or equivalent designs such as IEC Design N (IEC);
(6) Operates on polyphase alternating current 60-hertz sinusoidal power; and
(7) Includes, but is not limited to, construction utilizing special endshields, bases,
mounting configurations, or any combination of such.”
Since in the NEMA proposals the term “electric motor” is a part of all of the definitions of general
purpose motors, definite purpose motors, and special purpose motors then electric motor
assemblies of all of those types with special endshields, bases, mounting configurations, or any
combination of such are covered by the above proposal.
26
15. DOE requests comment on its instructions for testing electric motors with nonstandard base, feet, or mounting configurations.
NEMA Comment – NEMA is unable to locate any proposed test procedure in Appendix B to
Subpart B regarding testing electric motors with non-standard base, feet, or mounting
configuration. On page 38473 of the NOPR DOE indicated that at the present time DOE does
not plan to issue any particular test procedure for such electric motors. NEMA agrees that
special test procedures are not generally needed for those knowledgeable in the testing of
electric motors. It is common practice to adapt the method of mounting to the test facilities for
the purpose of conducting the test. However, it might be noted that based on the need that
DOE sees for stating a test procedure related to other methods of motor construction, that DOE
may be amiss in not covering this topic also. Please see the NEMA comments under Item (16)
for further information.
16. DOE seeks comment on any other testing difficulties that may arise from testing
electric motors with nonstandard base, feet, or mounting configurations.
NEMA Comment - A subject that may be important is that in the case of special mounting
configurations or footless motors, particularly TENV types, that the method of mounting used
not have an adverse effect on the cooling of the motor. For instance, it is not uncommon to see
a footless motor set in a V-shape or U-shape block or holder with straps around the motor to
restrain it from movement. The design of the block(s) may inhibit free convection cooling of the
TENV motor. Such mounting of the motor may also have a significant impact on open motors if
the block or holder covers any of the ventilation openings, particularly when the openings are on
the side of the motor enclosure.
NEMA recommends the following test procedure:
“Some adaptive fixtures may be required for mounting a motor on the test equipment when
testing an electric motor with a nonstandard base, feet, or mounting configuration. Care must
be taken to ensure that the method of mounting does not have an adverse effect on the
performance of the electric motor. In particular, the cooling of the motor must not be impeded
by any adaptive mounting fixtures.”
17. DOE requests comment regarding its proposed approach to testing electric motors
with bearings capable of horizontal orientation. DOE also requests comment on its
proposed approach to testing electric motors with bearings not capable of horizontal
orientation.
NEMA Comment – It is not clear as to what part of the discussions in the NOPR this request for
comments applies to. Since NEMA knows of no problem with testing standard horizontal
motors with bearings capable of horizontal orientation then it is presumed that what is being
requested is comment on bearings relative to the use in vertical motors and the proposed test
procedure in 4.7 of Appendix B to Subpart B.
NEMA agrees that vertical motors with bearings capable of operation in the horizontal position
can be tested in the horizontal position without modification. However, DOE may need to
provide the guidance that the manufacturer should be contacted as a part of the procedure for
making a determination that the vertical motor can be tested in the horizontal position.
The application of the test procedure appears to be very limited. The only definition of an
electric motor type that makes reference to vertical motors is that of “general purpose electric
27
motor (subtype II)” relative to “vertical solid shaft normal thrust motor (as tested in a horizontal
configuration)”. Given this direct reference, it is not obvious in the new definitions proposed in
the NOPR that DOE is proposing to cover any other type of vertical motor and include a relevant
test procedure.
The proposed title of 4.7 is “Vertical Electric Motors and Electric Motors with Bearings Incapable
of Horizontal Operation”. Since horizontal electric motors use bearings capable of horizontal
operation and vertical electric motors are identified as the first type of motors in the title, then
NEMA does not understand what types of electric motors other than horizontal or vertical that
DOE is referring to by “Electric Motors with Bearings Incapable of Horizontal Operation”. It
appears to NEMA that the title should be just “Vertical Electric Motors”.
If DOE is intending to introduce some definition somewhere that includes vertical motors other
than the type referred to in the definition of “general purpose electric motor (subtype II)” then
DOE should not restrict the test procedure to just testing in a horizontal position. There are
testing laboratories that can test motors in the vertical direction. DOE was in error in stating on
page 38460 of the NOPR that to test an electric motor using IEEE Standard 112 (Test Method
B) the electric motor is first mounted in a horizontal position. IEEE 112 does not restrict the use
of Test Method B to horizontal orientation. Test Method B can be used when testing vertical
motors in the vertical position when testing facilities are capable of measuring the output power
of the motor. DOE should recognize this and permit the use of these test facilities for testing
vertical electric motors.
To test in the vertical position some vertical motors with thrust bearings may require that a
vertical load be exerted on the thrust bearings. If this is not possible then the bearings may
need to be changed, such as to a 6000 series bearing, as DOE identifies in paragraph 4 of
Appendix B to Subpart B. If this requires that the motor then be tested in a horizontal position
then the motor should be tested in the horizontal position. However, NEMA knows of no reason
why the bearings should be changed if a vertical electric motor can be tested in its normal
orientation.
That said, NEMA agrees with the DOE’s proposal that vertical motors with thrust bearings can
have the thrust bearings replaced with standard (6000 series) bearings, but additionally
proposes that testing of the motor in the vertical orientation be permitted when proper test
facilities are available.
If a vertical motor is tested in a horizontal orientation, then the temperature of the intake
ventilation air for the motor in a suitable number of locations determined by the manufacturer
shall be measured immediately prior to the load test and recorded. If the intake ventilation air
temperature is higher than it is understood to be when the motor is operated vertically under
rated conditions, then this is an indication that the horizontal orientation allows more hot exhaust
air to recirculate to the motor air intake than the vertical orientation does, resulting in a higher
motor temperature and increased I2R losses. If it is suspected that the measured efficiency was
adversely affected in this manner, the opportunity should be given to re-test the motor with
baffles or other devices installed so that the amount of air recirculation more closely resembles
that in the vertical orientation.
It is not clear why motors with hollow shafts are referred to in the proposed test procedures
when DOE has not proposed any definition that includes vertical motors with hollow-shafts.
28
The replacement of oil-lubricated bearings should be required only if the oil-lubricated bearings
cannot be used in the orientation in which the vertical electric motor is to be tested. If the
bearings must be changed then that is already covered by the prior sentence in the test
procedure.
It is assumed that DOE will take into account any change in losses relative to the method of
testing and any modifications made for testing when establishing any energy conservation
standards for vertical motors of various types.
Based on the present definitions in §431.12 and those proposed in the NOPR and assuming
that vertical motors of various types are to be included, NEMA recommends that the proposed
test procedure be revised as:
“4.7 Vertical Electric Motors:
Vertical electric motors shall be tested in a horizontal or vertical configuration according to the
test facilities available and the construction of the vertical electric motor. If the unit under test
must be oriented horizontally, but cannot be operated in a horizontal position without
modification due to its bearing construction, the vertical electric motor’s bearing(s) shall be
removed and replaced with standard bearings. Similar consideration of changing the bearings is
to be given to testing of electric motors with thrust bearings in a vertical position if the thrust
bearing(s) require that a vertical load be applied to the shaft during testing. Any coupling or
other adapter required for connection of the vertical electric motor to the test equipment shall
provide sufficient clearance as necessary for proper connection. When tested in a horizontal
orientation the intake ventilation air for open vertical electric motors shall be monitored for the
purpose of determining if the hot exhaust air is being recirculated through the motor. If such
occurs, then temporary baffling or some other barrier may be required to prevent such
recirculation.”
18. DOE requests comments on its preliminary decision not to propose any definitions
for vertical motors.
NEMA Comment – Based on over 20 years of interpretation and application that the present
definitions in §431.12 exclude nearly all vertical motors, it is NEMA’s understanding that only
vertical solid shaft normal thrust general purpose electric motors (subtype II) are included within
the scope of the present and proposed definitions for §431.12. If it is DOE’s intent to include
other types of vertical motors in the proposed definitions of particular types of definite purpose
and special purpose electric motors then it is not obvious.
In the 1997 Policies Statement the only type of vertical motor that DOE referred to was a vertical
motor with normal thrust. Such motors were classified as being outside of the scope of “electric
motor” as defined in EPCA at that time. DOE did also refer to the applicable mounting
arrangements for foot-mounted “electric motors” as F1, F2; W1-4; and C1, 2 -- all horizontal
arrangements. NEMA assumes that for the purpose of this NOPR it is intended that electric
motors of the vertical type be included as covered products and that any such electric motors
added as newly covered electric motors by a Final Rule are considered to be either definite
purpose electric motors or special purpose electric motors as indicated in the 1997 Policies
Statement.
29
Based on the Executive Summary, NEMA offers the following proposal as a way to clearly
identify that vertical motors of the appropriate types will be included in the scope of covered
electric motors:

“Definite purpose electric motor means any electric motor that:
(1) Is rated at 600 volts or less;
(2) Is designed to operate in a horizontal or vertical orientation; and
(3) Cannot be used in most general purpose applications and is designed either:
(i) To standard ratings with standard operating characteristics or standard mechanical
construction for use under service conditions other than usual, such as those specified in
NEMA MG1– 2009, paragraph 14.3, ‘‘Unusual Service Conditions,’’ (incorporated by
reference, see §431.15); or
(ii) For use on a particular type of application.”

“Special purpose electric motor means any electric motor, other than a general purpose
electric motor or definite purpose electric motor, that:
(1) Is rated at 600 volts or less;
(2) Is designed to operate in a horizontal or vertical orientation; and
(3) Has special operating characteristics or special mechanical construction, or both,
designed for a particular application.”
By incorporating the feature of vertical motors in the above definitions then vertical TENV
definite purpose electric motors, vertical immersible definite purpose electric motors, etc. will be
included.
19. DOE seeks comments on its proposed instructions for dealing with the various
construction differences found between vertical and horizontal motors, in particular, test
methods for vertical motors with hollow shafts.
NEMA Comment - See NEMA comments under Item (item 17).
NEMA believes the requirements appearing in the second to last sentence of the proposed
paragraph 4.7 for Appendix B to Subpart B of Part 431 are too specific and/or counterproductive
and, therefore, should be removed. That sentence is: “Finally, if the unit under test contains a
hollow-shaft, a solid-shaft shall be inserted, bolted to the non-drive end of the motor and welded
on the drive end.” NEMA believes the requirement to bolt a solid-shaft to the non-drive end of
the motor is too specific. References to the drive end and the non-drive end for vertical motors
can be confusing due to the fact that, depending on the construction of the motor, the thrust
bearing can be located either on the upper or the lower end of the motor when it is mounted
vertically. Additionally, depending on the construction of the hollow-shaft vertical motor, the test
facility will sometimes attach the solid shaft protrusion so that it couples with the loading device
on the end of the motor that would be facing down when the motor is oriented vertically and
other times attach it so that it couples with the loading device on the end of the motor that would
be facing up when the motor is oriented vertically. NEMA believes the requirement to weld the
solid-shaft on the drive end would render the motor unusable in its intended application outside
of the test facility. For these reasons, NEMA proposes that these specific test instructions be
replaced with the more general instructions in the NEMA proposal for the vertical electric motor
test procedure that appears in the response to Item 17: “Any coupling or other adapter required
for connection of the vertical electric motor to the test equipment shall provide sufficient
clearance as necessary for proper connection.”
30
19.A NEMA notes that on page 38471 “DOE is declining to propose the use of Test Method E
for vertical motors. However, DOE requests additional comments and test data that
demonstrate any differences in the results of testing under Test Method E and Test Method B
for the same basic model of vertical motor.”
NEMA Comment – Comparison of results of Test Method E to Test Method B is not an issue
here. The DOE proposed use of Test Method B in a horizontal orientation is actually a deviation
from the present standard practice of using Test Method E in a vertical orientation. The use of
Test Method B of IEEE 112 was introduced in EPAct of 1992 as the applicable test standard,
based on industry practices, for electric motors as defined in EPAct. In adding electric motors to
10 CFR DOE structured the rules and regulations around horizontal general purpose motors as
used in most general purpose applications. In the 1997 Policies Statement DOE identified
vertical motors as outside of the scope of “electric motors”. In EISA, when Congress added
vertical solid shaft normal thrust general purpose electric motors (subtype II) Congress
designated that such vertical electric motors also be tested in a horizontal configuration, making
Method B of IEEE 112 the applicable test standard for those types of electric motors by default.
In this NOPR DOE seems to suggest that DOE is proposing to add other types of vertical
electric motors for which test procedures must be established. As far as NEMA knows there is
no provision in EPAct or EISA which prohibits DOE from adopting the use of the existing
standard test procedure applicable to a particular type of electric motor when that type is added
as a new covered product. The use of IEEE 112 Test Method E for testing vertical motors when
the bearing construction does not permit testing the vertical motor in a horizontal position as
stated in NEMA MG1-2009 paragraph 12.58.1 has been the standard practice for over 20 years.
DOE has provided no supportive reason as to why DOE proposes to deviate from that standard
practice and the test procedure that has been used for determining the efficiency of such
vertical motors.
In the existing Appendix B to Subpart B the primary test procedure for determining efficiency is
given as:
“2. Test Procedures.
Efficiency and losses shall be determined in accordance with NEMA MG1-2009,
paragraph 12.58.1, “Determination of Motor Efficiency and Losses,” (incorporated by
reference, see §431.15) and either:”
IEEE 112 Method B and CSA C390 are specified to be used in conjunction with the
requirements of MG1-2009, paragraph 12.58.1. Up until such time as vertical electric motors,
other than vertical solid shaft normal thrust general purpose electric motors (subtype II), would
be included in the scope of covered products there has been no reason to include other test
procedures called out in NEMA MG1-2009, paragraph 12.58.1. However, now that other types
of vertical electric motors may be added as covered products then DOE should recognize that in
addition to IEEE 112 Method B the valid standard IEEE 112 Method E test procedure has also
been accepted for use when testing motors in the vertical orientation.
Based on the test procedure that DOE is proposing in paragraph 4.7 of Appendix B to Subpart B
it is unlikely that the efficiency obtained from testing of the vertical electric motor in a horizontal
position after changing out of the bearings and other related parts will be the same as the
efficiency if the vertical motor is tested in the proper vertical position with no modification. This
may be particularly true in the case of additional losses when thrust bearings are installed for
the normal vertical orientation. DOE does not address in the NOPR what this difference is
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expected to be. This difference should be of as much concern as any perceived difference
between the use of IEEE 112 Test Method E and IEEE 112 Test Method B.
Obviously, if DOE is concerned that the use of industry standard IEEE 112 Test Method E
applied in a proper vertical configuration may yield results different from that of IEEE 112 Test
Method B applied in an artificial horizontal configuration then this must be considered in the
establishment of any efficiency standards applicable to such vertical motors.
NEMA again proposes that IEEE 112 Method E be added as a valid test procedure in paragraph
2 of Appendix B to Subpart B and all other paragraphs in Subparts B and U where it is
necessary to identify the applicable test standards for vertical motors. As for the test procedure
in paragraph 4.7, NEMA recommends the following revision to that proposed under Item (17)
above in order to provide consistency with the present regulations for vertical solid shaft normal
thrust general purpose electric motors and allow for the use of Test Method E in accordance
with NEMA MG1-2009, paragraph 12.58.1:
“4.7 Vertical Electric Motors:
Vertical solid shaft normal thrust general purpose electric motors (subtype II) shall be tested in a
horizontal configuration in accordance with IEEE 112 Method B. According to the test facilities
available and construction of the vertical electric motor, vertical electric motors of other types
shall be tested in a horizontal configuration following the IEEE 112 Method B test procedure or
in a vertical configuration following either the IEEE 112 Method B or Method E test procedure. If
the unit under test must be oriented horizontally, but cannot be operated in a horizontal position
without modification due to its bearing construction, the vertical electric motor’s bearing(s) shall
be removed and replaced with standard bearings. Similar consideration of changing the
bearings is to be given to testing of electric motors with thrust bearings in a vertical position if
the thrust bearing(s) require that a vertical load be applied to the shaft during testing. Any
coupling or other adapter required for connection of the vertical electric motor to the test
equipment shall provide sufficient clearance as necessary for proper connection. When tested
in a horizontal orientation the intake ventilation air for open vertical electric motors shall be
monitored for the purpose of determining if the hot exhaust air is being recirculated through the
motor. If such occurs, then temporary baffling or some other barrier may be required to prevent
such recirculation.”
19.B NEMA notes that on page 38473 of the NOPR “DOE requests comment regarding its
proposed approach to testing motors with thrust bearings only capable of vertical operation.
DOE also requests comment on its proposed approach to testing motors with all types of
bearings that are capable of horizontal operation, in particular, its proposed approach to testing
motors with sleeve bearings.”
NEMA Comment – NEMA is unable to find any proposed test procedure in Appendix B to
Subpart B regarding thrust bearings that are only capable of vertical operation. In 4.7 the
reference to “electric motors with thrust bearings” is assumed to refer to horizontal and vertical
electric motors. If an electric motor is to be tested in an orientation which is not the normal
orientation, then NEMA agrees that changing of the bearings and other related parts may be
necessary to perform the testing, provided the effect on the test results of such a change is
understood. As noted in the NEMA comments under Item 17 some vertical motors with thrust
bearings may require that a vertical load be applied to the motor shaft during testing in the
vertical position. In such a case modification of the unit may be required, whether for horizontal
testing or vertical testing. Some bearings may require oil or other lubricant circulation systems
for proper use, but that is a normal method of operation for that type of bearings. In general, the
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motor manufacturer should be consulted regarding any modifications that may be required for
testing.
NEMA considers that the NEMA recommendation for 4.7 under Item (17) addresses the
concerns expressed by DOE relative to bearings.
20. DOE requests comment on its decision not to propose additional test procedure
clarifications for motors with sleeve bearings or a definition for these motor types.
Page 38473 states it as - DOE also requests comment on its proposed approach to testing
motors with all types of bearings that are capable of horizontal operation, in particular, its
proposed approach to testing motors with sleeve bearings.
NEMA Comment – NEMA agrees that no definition is needed covering electric motors with
sleeve bearings. NEMA knows of no reason that the normal IEEE 112 Method B, or Method E
where applicable, test procedure is not sufficient for testing electric motors with sleeve bearings.
21. DOE requests comment regarding the effect of sleeve bearings on a motor’s tested
efficiency.
NEMA Comment – Sleeve bearings have associated losses which must be provided for by the
input power to the electric motor. Those losses result in a decrease in the value of efficiency
that might be determined that does not include such losses. However, testing with the sleeve
bearings in place is a measure of the efficiency of the electric motor as exhibited in normal
operation.
22. DOE requests comment on its proposed definition for air-over electric motor, and the
decision to include both open and enclosed frame motors under the same definition.
NEMA Comment - The NEMA MG1-1.26.9 definition of a totally enclosed air-over (TEAO)
machine is a totally enclosed frame-surface cooled machine intended for exterior cooling by a
ventilating means external to the machine. This distinguishes such a machine from one in
which the ventilating means is external to the machine, but the air is ducted to and from and
circulated through the machine. An example of the latter type is a pipe-ventilated machine. The
definition proposed by DOE does not make this distinction. The DOE proposed definition might
be improved by referring to the air as being free-flowing, which could be over an enclosed
electric motor or through an open electric motor.
If DOE does establish standards for such motors then in accordance with the DOE 1997
Policies Statement and proposed changes to Appendix B of Subpart B the definition should be
for that of an “air-over definite purpose electric motor”. However, if DOE does not establish
standards and still sees the need for a definition then the definition should be for that of an “airover definite purpose motor”.
As explained in the Executive Summary above the proposed definition is inadequate as it is
neither sufficiently complete nor clear in other respects. Assuming that the revisions to the
definitions as described in the Executive Summary are made and that the purpose of the
definition is for exemption of such types of motors then a proper definition would be:
“Air-over definite purpose motor means a definite purpose motor that is designed to be
cooled by a free flow of air provided by a ventilating means external to, and not supplied
with, the motor.”
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However, NEMA would like to repeat its previous comments that there is no need for any
definition of “air-over definite purpose motor” or “air-over definite purpose electric motor” if
efficiency standards are not established for such.
If DOE does not include the NEMA recommended revisions to the definition of “electric motor”
and “definite purpose electric motor” then the performance and construction characteristics
included in those definitions would need to be included in any definition of “air-over definite
purpose electric motor”.
Should DOE intend to reference IEC IP and IC codes in the item being defined or in the
definition, NEMA understands that the corresponding codes are IPXX and IC018. For IPXX the
“XX” designates that the machine can be of any enclosure. IC018 designates that the circuit
arrangement “0” is for free circulation, the method “1” of moving (i.e., circulating) the interior
cooling air is related to parts on the rotor or shaft which are rotating at the operating speed, and
that the method “8” of movement of the secondary exterior cooling air is by forced flow provided
external to the motor.
23. DOE requests comment on the decision to not require air-over electric motors to
meet energy conservation standards at this time.
NEMA Comment – NEMA agrees that the difficulties of testing to determine the efficiency of an
air-over motor make the establishment of efficiency standards impractical.
24. DOE requests comment on its proposed definition of component set of an electric
motor.
NEMA Comment – The confusion between what constitutes a “component set” and what
constitutes a “partial electric motor” that DOE discusses on page 38474 of the NOPR arose
because of the lack of a standard definition of either term. However, assuming that a proper
clear definition of “partial motor” (see Item 7.A) may be adopted then this confusion would no
longer exist.
In the proposed definition of “component set” DOE is, in essence, stating that a “component set
is a combination of motor parts that are not all the parts required to be those of a partial motor.”
Such a definition is not needed for something that is not to be regulated. The definition itself
may unintentionally introduce confusion as to what is a “partial motor”.
DOE has presented nothing within the proposed definitions indicating how “component sets”
might be used nor why it is necessary to define such, particularly since a “component set” is not
an “electric motor”.
NEMA does not see any need for a definition of “component set” and recommends that no
definition be included in §431.12. The definition of “partial motor” should be adequate to
properly identify any combination of motor parts that are to be covered by standards.
25. DOE is open to comment on its tentative decision to not require component sets of
electric motors to meet any particular energy conservation standards.
NEMA Comment – NEMA agrees that component sets not be required to meet any energy
conservation standards. In particular, it is not clear how any standards could be established for
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a component set that lacks a wound stator or a rotor. If a component set is used by an entity to
construct a motor then that motor should be covered by any required standards if the final
product is a type of electric motor for which standards apply.
26. DOE seeks feedback on its proposed definition for liquid-cooled electric motors.
NEMA Comment – As explained in the Executive Summary NEMA sees no need for a definition
of “liquid-cooled electric motor”. It should be obvious that none of the proposed definitions for
definite purpose electric motors or special purpose electric motors which may be covered by
energy conservation standards describe an electric motor of a type that would be confused with
a motor that is cooled by circulating liquid within the motor structure and requires a source of
cooling liquid. The reverse is also true. No motor that is cooled by circulating liquid within the
motor structure would be confused with any of the types of definite purpose or special purpose
motors defined by the proposed definitions.
However, as explained in the Executive Summary, if DOE still sees the need to include a
definition for a product for which test procedures and energy conservation standards are not
being established then the definition should be for that of a “liquid-cooled definite purpose
motor” and not a “liquid-cooled definite purpose electric motor”. In the proposed definition
NEMA understands that “liquid-filled conductors” is intended to represent the piping or channels
within the enclosure structure through which the liquid may flow, but can be confused with
special motors in which the liquid flows through actual hollow electrical conductors in the stator
or rotor. To remove that confusion, NEMA recommends the definition, if needed, be modified to
be:
“Liquid-cooled definite purpose motor means a motor that is cooled by circulating liquid with the
liquid coming into direct contact with machine parts, typically the enclosure.”
If DOE does not include the NEMA recommended revisions to the definition of “electric motor”
and “definite purpose electric motor” and defines “liquid-cooled definite purpose electric motor”
then the performance and construction characteristics included in the former definitions would
need to be included in the definition of “liquid-cooled definite purpose electric motor”.
Should DOE intend to reference IEC IP and IC codes in the item being defined or in the
definition, NEMA understands that the corresponding codes are IPXX and ICA1Y7. For IPXX
the “XX” designates that the machine can be of any enclosure as the cooling liquid is contained
within some arrangement of pipes, ducts, or passages in the motor. IC3A1Y7 designates that
the circuit arrangement “3” is for the coolant provided by inlet and outlet pipes or ducts, the
(higher temperature) primary coolant “A” is air, the method “1” of moving (i.e., circulating) the
interior cooling air is related to parts on the rotor or shaft which are rotating at the operating
speed, the secondary coolant “Y” is to be designated (such as “W” for water or “U” for oil) and
that the method “7” of movement of the secondary coolant is by a separate and independent
coolant system. The designation IC3A1Y7 may be shortened to IC31Y as explained in Part 6 of
NEMA MG1-2009.
27. DOE seeks comment on its tentative decision not to cover liquid cooled electric
motors, primarily because of the testing difficulties encountered when testing them,
namely the number of testing variables that are introduced by the additional coolant
system and pump apparatus.
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NEMA Comment – NEMA agrees that proper testing of liquid cooled definite purpose motors is
one concern making it difficult to verify that a design would meet any applicable energy
conservation standard. (See NEMA comments to Item 28.) Another factor that must be
considered is that liquid cooling is used with motors in specialized applications where it is
important to obtain a high power density within a limited size. Different physical sizes may be
used for the same power rating for different applications for different speed-torque performance,
as needed. That also makes it difficult to establish any particular energy conservation standard
for a rating. NEMA agrees that energy conservation standards should not be established for
motors that rely on liquid cooling.
28. DOE is open to comment regarding any test procedure standards or additional test
procedure guidance language that would take into account all variables involved in
testing liquid cooled motors and allows this motor type to be tested in a consistent,
manageable, and repeatable manner.
NEMA Comment – NEMA is not aware of any consistent defined environment common to all
types of motors which rely on liquid cooling. Some motors may be operated in an open
environment and rely on both free convection as well as liquid cooling to maintain acceptable
temperature levels. Other motors may be operated in confined spaces and rely on only the
liquid cooling for maintaining acceptable temperature levels. Other motors may be operated in
an area where there is a source of externally supplied ventilating air as well as the liquid
cooling. It is very difficult to properly simulate the various environments in a test facility where
the test motor is required to be connected to a dynamometer.
29. DOE requests comment on its proposed definition of submersible electric motor.
NEMA Comment – As explained in the Executive Summary NEMA sees no need for a definition
of “submersible electric motor”. It should be obvious that none of the proposed definitions for
definite purpose electric motors or special purpose electric motors which may be covered by
energy conservation standards describe an electric motor of a type that would be confused with
a motor that must be submerged in a liquid at all times that the motor is operated. The reverse
is also true. No motor that must be submerged in a liquid at all times that the motor is operated
would be confused with any of the types of definite purpose or special purpose motors defined
by the proposed definitions. In particular, it should be obvious that with the changes to the
definition that NEMA proposes under Item 8 that an immersible definite purpose electric motor
can be operated without immersion in a liquid and is designed for immersion for only a short
limited time, during which time the motor may not be operable.
However, as explained in the Executive Summary, if DOE still sees the need to include a
definition for a product for which test procedures and energy conservation standards are not
being established then the definition should be for that of a “submersible definite purpose motor”
and not a “submersible definite purpose electric motor”. In the definition it is not necessary to
include “continuous” as the motor is not intended to be operated outside of the liquid for any
period of time. If a definition is needed then NEMA recommends the definition be:
“Submersible definite purpose motor means a motor designed for operation only while
submerged in liquid.”
If DOE does not include the NEMA recommended revisions to the definition of “electric motor”
and “definite purpose electric motor” and defines “submersible definite purpose electric motor”
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then the performance and construction characteristics included in the former definitions would
need to be included in the definition of “submersible definite purpose electric motor”.
Should DOE intend to reference IEC IP codes in the item being defined or in the definition,
NEMA understands that the corresponding code is IP68. For IP68 the “6” designates that the
motor is protected against the ingress of dust and the “8” designates that the motor is protected
against continuous submersion. There is no common IC code as it depends on the method in
which the motor is cooled and the type of liquid in which the motor is submersed.
30. DOE requests comment on whether it is correct that there are no test facilities
capable of conducting performance tests on submersible electric motors.
NEMA Comment – NEMA is not aware of any test facilities available for conducting an IEEE
112 Method B test on a motor while submerged in liquid.
31. DOE requests comment on its proposed definition for definite purpose, inverter-fed
electric motors.
NEMA Comment – As explained in the Executive Summary NEMA sees no need for a definition
of “definite purpose inverter fed electric motor”. It is assumed that the type of motor the
proposed definition is intended to refer to is one designed and marked in accordance with Part
31 of NEMA MG1-2009. When compared with the definition of “electric motor” as NEMA
proposes in the Executive Summary then it should be obvious that the motor is not designed to
meet the performance and construction requirements of an “electric motor”. Also, the motor is
not marked with a NEMA Design Type nor the National Electrical Code locked rotor kVA/Hp
code required of motors intended for connection directly to sinusoidal line power. Many such
motors are not rated for operation at 60 Hz as the base rating may be at a lower frequency. A
definition would be needed only if there was a clear indication that a motor designed for
operation on inverter power appears to meet the definition of “electric motor” in the Executive
Summary in all respects. Properly designed and marked motors in accordance with Part 31 of
MG1-2009 do not meet that definition of “electric motor”.
However, as explained in the Executive Summary, if DOE still sees the need to include a
definition for a product for which test procedures and energy conservation standards are not
being established then in keeping with the method of identification used for all other definitions
the definition should be for that of an “inverter-fed definite purpose motor” and not a “definite
purpose inverter-fed electric motor”. If it is needed then NEMA recommends the definition be
(Note that there should not be a comma included in the name of the object being defined):
“Inverter-fed definite-purpose motor means a definite purpose motor that is designed for
operation solely with an inverter, and is not defined for across-the-line starting when directly
connected to polyphase, sinusoidal line power.”
If DOE does not include the NEMA recommended revisions to the definition of “electric motor”
and “definite purpose electric motor” and defines “inverter-fed definite purpose electric motor”
then the performance and construction characteristics included in the former definitions would
need to be included in the definition of “inverter-fed definite purpose electric motor”.
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32. DOE seeks comment on its preliminary decision to continue to not require definitepurpose, inverter-fed electric motors to meet any expanded energy conservation
standards for electric motors.
NEMA Comment – NEMA agrees that energy conservation standards should not be established
for motors intended for operation solely with an inverter.
Additional NEMA Comments
A) In Appendix B to Subpart B Line 8 of paragraph (4)
The words “a motor” should be changed to “an electric motor”
B) Comment regarding covered versus non-covered products:
The inclusion of definitions of types of “electric motors” for the purpose of excluding those types
from being covered by energy conservation standards appears to be in conflict with §431.2 that
states that “covered equipment means any electric motor, as defined in §431.12”. The NEMA
proposal to define types of “definite purpose motors” and “special purpose motors”, rather than
“definite purpose electric motors” and “special purpose electric motors”, when needed for stating
an exclusion would seem to resolve this conflict. However, as noted in the other comments
NEMA sees no need to define any motor type for the purpose of stating an exclusion.
C) Comment regarding the proposed definition of “standard bearing” in paragraph 4 of
Appendix B to Subpart B:
The proposed definition of “standard bearing” includes the characteristic of being “open”.
Bearings require proper lubrication during operation. Some endshields contain provisions for
the containment of lubricating materials, such as grease, for bearings. In that case an open
bearing may be acceptable. Other endshields may not have such provisions, in which case a
shielded or double-shielded pre-lubricated bearing may be needed. This can be a concern
when replacing existing bearings of different type, such as thrust bearings, with radial ball
bearings. It is preferred that the lubricant be grease as oil may run out of the bearing during
testing, particularly when not testing in the designed orientation. Specifying a “grease lubricated
double-shielded” bearing instead of an “open” bearing may be the best overall choice for the
proposed definition of “standard bearing”.
NEMA proposes the following changes to the stated definition: For the purposes of this
Appendix, a ‘‘standard bearing’’ is a 6000 series, grease-lubricated double-shielded open,
single-row, deep groove, radial ball bearing, however an open bearing can be used when
provisions for grease lubrication are provided.
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