Appendix B to Subpart B of Part 431 - Uniform Test Method for Measuring the Efficiency of Electric Motors

Appendix B to Subpart B of Part 431 - Uniform Test Method for Measuring Nominal Full Load Efficiency of Electric Motors

0. Incorporation by Reference

(a) In § 431.15, DOE incorporated by reference the entire standard for CSA C390-10, IEC 60034-1:2010, IEC 60034-2-1:2014, IEC 60051-1:2016, and IEEE 112-2017; however, only enumerated provisions of those documents are applicable as follows:

(i) CSA C390-10:

(1) Section 1.3 “Scope,” as specified in section 2(1) of this appendix;

(2) Section 3.1 “Definitions,” as specified in section 2(1) of this appendix;

(3) Section 5 “General test requirements - Measurements,” as specified in section 2(1) of this appendix;

(4) Section 7 “Test method,” as specified in section 2(1) of this appendix;

(5) Table 1 “Resistance measurement time delay,” as specified in section 2(1) of this appendix;

(6) Annex B “Linear regression analysis,” as specified in section 2(1) of this appendix; and

(7) Annex C “Procedure for correction of dynamometer torque readings” as specified in section 2(1) of this appendix.

(ii) IEC 60034-1:2010:

(1) Section 7.2 as specified in section 2(2) of this appendix;

(2) Section 8.6.2.3.3 as specified in section 2(2) of this appendix; and

(3) Table 5 as specified in section 2(2) of this appendix.

(iii) IEC 60034-2-1:2014:

(1) Method 2-1-1B as specified in section 2(2) and section 3, of this appendix;

(2) Section 3 “Terms and definitions” as specified in section 2(2) of this appendix;

(3) Section 4 “Symbols and abbreviations” as specified in section 2(2) of this appendix;

(4) Section 5 “Basic requirements” as specified in section 2(2) of this appendix; and

(5) Section 6.1.3 “Method 2-1-1B - Summation of losses, additional load losses according to the method of residual losses” as specified in section 2(2) of this appendix.

(iv) IEEE 112-2017:

(1) Test Method B, Input-Output With Loss Segregation as specified in section 2(3), section 3, and section 3.8 of this appendix;

(2) Section 3 “General” as specified in section 2(3) of this appendix;

(3) Section 4 “Measurements” as specified in section 2(3) of this appendix;

(4) Section 5 “Machine losses and tests for losses” as specified in section 2(3) of this appendix;

(5) Section 6.1 “General” as specified in section 2(3) of this appendix;

(6) Section 6.4 “Efficiency test method B - Input-output with loss segregation” as specified in section 2(3) of this appendix; and

(7) Section 9.4 “Form B - Method B”, and Section 9.5 “Form B2 - Method B calculations” as specified in section 2(3) of this appendix.

(b) In § 431.15, DOE incorporated by reference the following enumerated provisions of NEMA MG 1-2009:

(i) Paragraph 12.58.1, “Determination of Motor Efficiency and Losses” as specified in the introductory paragraph to section 2 of this appendix, and

(ii) [Reserved]

(c) In cases where there is a conflict, the language of this appendix takes precedence over those documents. Any subsequent amendment to a referenced document by the standard-setting organization will not affect the test procedure in this appendix, unless and until the test procedure is amended by DOE. Material is incorporated as it exists on the date of the approval, and a notice of any change in the material will be published in the Federal Register.

1. Definitions.

Definitions contained in §§ 431.2 and 431.12 are applicable to this appendix.

2. Test Procedures

Efficiency and losses must be determined in accordance with NEMA MG 1-2009 (incorporated by reference, see § 431.15), paragraph 12.58.1, “Determination of Motor Efficiency and Losses,” and one of the following testing methods:

(1) CSA C390-10 (incorporated by reference, see § 431.15), Section 1.3 “Scope”, Section 3.1 “Definitions”, Section 5 “General test requirements - Measurements”, Section 7 “Test method”, Table 1 “Resistance measurement time delay”, Annex B “Linear regression analysis” and Annex C “Procedure for correction of dynamometer torque readings.”

(2) IEC 60034-2-1:2014 (incorporated by reference, see § 431.15), Method 2-1-1B, Section 3 “Terms and definitions”, Section 4 “Symbols and abbreviations”, Section 5 “Basic requirements”, Section 6.1.3 “Method 2-1-1B - Summation of losses, additional load losses according to the method of residual losses.” The supply voltage shall be in accordance with section 7.2 of IEC 60034-1:2010 (incorporated by reference, see § 431.15). The measured resistance at the end of the thermal test shall be determined in a similar way to the extrapolation procedure described in section 8.6.2.3.3 of IEC 60034-1:2010, using the shortest possible time instead of the time interval specified in Table 5 therein, and extrapolating to zero. The measuring instruments for electrical quantities shall have the equivalent of an accuracy class of 0,2 in case of a direct test and 0,5 in case of an indirect test in accordance with IEC 60051-1:2016 (incorporated by reference, see § 431.15), or

(3) IEEE 112-2017, (incorporated by reference, see § 431.15), Test Method B, Input-Output With Loss Segregation, Section 3 “General”, Section 4 “Measurements”, Section 5 “Machine losses and tests for losses”, Section 6.1 “General”, Section 6.4 “Efficiency test method B - Input-output with loss segregation”, Section 9.4 “Form B - Method B”, and Section 9.5 “Form B2 - Method B calculations.”

3. Procedures for the Testing of Certain Electric Motor Types

Prior to testing according to CSA C390-10, IEC 60034-2-1:2014 Method 2-1-1B, or IEEE 112-2017 Test Method B, each basic model of the electric motor types listed below must be set up in accordance with the instructions of this section to ensure consistent test results. These steps are designed to enable a motor to be attached to a dynamometer and run continuously for testing purposes. For the purposes of this appendix, a “standard bearing” is a 6000 series, either open or grease-lubricated double-shielded, single-row, deep groove, radial ball bearing.

3.1 Brake Electric Motors:

Brake electric motors shall be tested with the brake component powered separately from the motor such that it does not activate during testing. Additionally, for any 10-minute period during the test and while the brake is being powered such that it remains disengaged from the motor shaft, record the power consumed (i.e., watts). Only power used to drive the motor is to be included in the efficiency calculation; power supplied to prevent the brake from engaging is not included in this calculation. In lieu of powering the brake separately, the brake may be disengaged mechanically, if such a mechanism exists and if the use of this mechanism does not yield a different efficiency value than separately powering the brake electrically.

3.2 Close-Coupled Pump Electric Motors and Electric Motors with Single or Double Shaft Extensions of Non-Standard Dimensions or Design:

To attach the unit under test to a dynamometer, close-coupled pump electric motors and electric motors with single or double shaft extensions of non-standard dimensions or design must be tested using a special coupling adapter.

3.3 Electric Motors with Non-Standard Endshields or Flanges:

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 meeting NEMA or IEC specifications. The replacement component should be obtained from the manufacturer or, if the manufacturer chooses, machined by the testing laboratory after consulting with the manufacturer regarding the critical characteristics of the endshield.

3.4 Electric Motors with Non-Standard Bases, Feet or Mounting Configurations

An electric motor with a non-standard base, feet, or mounting configuration may be mounted on the test equipment using adaptive fixtures for testing as long as the mounting or use of adaptive mounting fixtures does not have an adverse impact on the performance of the electric motor, particularly on the cooling of the motor.

3.5 Electric Motors with a Separately-powered Blower:

For electric motors furnished with a separately-powered blower, the losses from the blower's motor should not be included in any efficiency calculation. This can be done either by powering the blower's motor by a source separate from the source powering the electric motor under test or by connecting leads such that they only measure the power of the motor under test.

3.6 Immersible Electric Motors

Immersible electric motors shall be tested with all contact seals removed but be otherwise unmodified.

3.7 Partial Electric Motors:

Partial electric motors shall be disconnected from their mated piece of equipment. After disconnection from the equipment, standard bearings and/or endshields shall be added to the motor, such that it is capable of operation. If an endshield is necessary, an endshield meeting NEMA or IEC specifications should be obtained from the manufacturer or, if the manufacturer chooses, machined by the testing laboratory after consulting with the manufacturer regarding the critical characteristics of the endshield.

3.8 Vertical Electric Motors and Electric Motors with Bearings Incapable of Horizontal Operation:

Vertical electric motors and electric motors with thrust bearings shall be tested in a horizontal or vertical configuration in accordance with IEEE 112-2017 Test Method B, depending on the testing facility's capabilities and construction of the motor, except if the motor is a vertical solid shaft normal thrust general purpose electric motor (subtype II), in which case it shall be tested in a horizontal configuration in accordance with IEEE 112-2017 Test Method B. Preference shall be given to testing a motor in its native orientation. If the unit under test cannot be reoriented horizontally due to its bearing construction, the electric motor's bearing(s) shall be removed and replaced with standard bearings. If the unit under test contains oil-lubricated bearings, its bearings shall be removed and replaced with standard bearings. 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. Enough clearance shall be maintained such that attachment to a dynamometer is possible.

[77 FR 26638, May 4, 2012, as amended at 78 FR 75994, Dec. 13, 2013; 86 FR 22, Jan. 4, 2021; 86 FR 3747, Jan. 15, 2021]