CHAPTER 3. MARKET AND TECHNOLOGY ASSESSMENT

TABLE OF CONTENTS

**3. 1**  **INT RODUCTION** 

**.................................... ..........................................................................**  **1**

**3. 2**  **MARKE T**  **ASSESSMENT**

**............................... ..................................................................**  **1**

**3. 2.1**  **Small Electric**  **Motor Definition** 

**............... ..............................................................**  **1**

**3. 2.1.1**  **General­Purpose Alternating­Current**  **Motor**

**... ...........................................**  **3**

**3. 2.1.2**  **Categories of**  **Induction Motors** 

**.................................................................. 5** 

**3. 2.1.3**  **Frame Sizes**  **and Metric**  **Equivalents**

**.......... .................................................**  **7**

**3. 2.1.4**  **Motor Enclosure** 

**.......................................................................................... 8** 

**3. 2.2**  **Small Electric**  **Motor Nameplates**  **and Terminology** 

**.............................................. 8** 

**3. 2.3**  **Pro posed**  **Equipment Classes** 

**................................................................................ 11** 

**3. 2.3.1**  **Representative Units** 

**........................ .........................................................**  **13**

**3. 2.3.2**  **Scaling Findings**  **from Representative**  **Units**

**.. ..........................................**  **20**

**3. 2.4**  **Shipments**

**.............................................................................................................. 21** 

**3. 2.5**  **Manufacturers and**  **Market Share** 

**................ ..........................................................**  **24**

**3. 2.5.1**  **Small Businesses** 

**....................................................................................... 24** 

**3. 2.6**  **Application and**  **Performance of**  **Existing Equipment** 

**.......................................... 25** 

**3. 2.7**  **Trade Associations** 

**................................................................................................ 25** 

**3. 2.7.1**  **National Electrical**  **Manufacturers Association** 

**........................................ 25** 

**3. 2.7.2**  **The Motors**  **and Motion**  **Association**

**........................................................ 26** 

**3. 2.8**  **Regulatory Programs** 

**............................................................................................ 26** 

**3. 2.9**  **Non­Regulatory Programs** 

**.................................................................................... 27** 

**3. 2.9.1**  **Department of**  **Energy Motor**  **Challenge Program** 

**.................................... 27** 

**3. 2.9.2**  **National Electrical**  **Manufacturers Association**  **Premium Efficiency**  **Motor**

**Program**

**..................................................................................................... 28** 

**3. 2.9.3**  **Consortium for**  **Energy Efficiency** 

**............ ................................................**  **29**

**3. 3**  **TECHN OLOGY**  **ASSESSMENT**

**........................... ..........................................................**  **29**

**2 3.3.1**  **Technology Options**  **for I R**  **Losses**

**............................................ ..........................**  **30**

**3. 3.2**  **Technology Options**  **for Core**  **Losses**

**................................................................... 31** 

**3. 3.2.1**  **Plastic Bonded**  **Iron Powder** 

**...................................................................... 33** 

**3. 3.2.2**  **Permanent Magnet**  **Electric Motor** 

**............. ...............................................**  **34**

**3. 3.3**  **Technology Options**  **for Friction**  **and Windage**  **Losses**

**........................................ 34** 

**3. 3.4**  **Technology Options**  **for Stray**  **Load Losses** 

**.......................................................... 34** 

**3. 3.5**  **Summary of**  **the Technology**  **Options Under**  **Consideration**

**................................. 35** 

LIST OF TABLES

**Table 3.2.1.**  **National Electrical**  **Manufacturers Association**  **Standard MG1–1987**  **Service Factor** 

**Requirements of**  **Small Electric**  **Motors**

**............... ...........................................................................**  **4**

**Table 3.2.2.**  **Minimum Locked­Rotor**  **Torque, Ounce­Feet** *

**.......................................................... 5** 

**Table 3.2.3.**  **Required Small**  **Electric Motor**  **Nameplate Information** 

**...................................... .....**  **10**

**Table 3.2.4.**  **Optional Small**  **Electric Motor**  **Nameplate Information** 

**...................................... .....**  **11**

**3­i Table**  **3.2.5. Example**  **of Equipment**  **Classes for**  **Capacitor­Start, Induction­Run**  **Small Electric** 

**Motors**

**.............................................. .............................................................................................**  **13**

**Table 3.2.7.**  **Representative Units**  **Selected for**  **the Preliminary**  **Notice of**  **Proposed Rulemaking20** 

**Table 3.2.9.**  **National Electrical**  **Manufacturers Association**  **Polyphase Small**  **Electric Motor** 

**Table 3.2.11.**  **National Electrical**  **Manufacturers Association**  **Capacitor­Start, Induction­Run** 

**Table 3.2.12.**  **Estimated Capacitor­Start,**  **Induction­Run Small**  **Electric Motor**  **National**

**Table 3.2.13.**  **Estimated Capacitor­Start,**  **Capacitor­Run Small**  **Electric Motor**  **National Table**  **3.2.6. Representative**  **Units Selected**  **for the**  **Determination Analysis** 

**............................. ...**  **14**

**Table 3.2.8.**  **Scaling from**  **Representative Motors**  **to all**  **Equipment Classes** 

**.............................. ..**  **21**

**Shipment Data,**  **2000**

**..................................................................................................................... 22** 

**Table 3.2.10.**  **Estimated Polyphase**  **Small Electric**  **Motor National**  **Shipments, 2007** 

**.................. 22** 

**Small Electric**  **Motor Shipment**  **Data, 2000** 

**............ ......................................................................**  **23**

**Shipments, 2007** 

**............................................................................................................................ 23** 

**Shipments, 2007** 

**............................................................................................................................ 24** 

**Table 3.3.1.**  **Core Steel**  **Grades, Thicknesses,**  **and Associated**  **Losses**

**.......................................... 33** 

**Table 3.3.2.**  **Summary of**  **Technology Options**  **for Improving**  **Efficiency**

**................................... .**  **35**

LIST OF FIGURES

**Figure 3.2.1.**  **Polyphase Small**  **Electric Motor**  **Shipments Broken**  **Down by**  **Pole Configuration**  **14**

**Figure 3.2.5.**  **Capacitor­Start, Induction­Run**  **Small Electric**  **Motor Shipments**  **Broken Down**  **by**

**Figure 3.2.6.**  **Capacitor­Start, Induction­Run**  **Small Electric**  **Motor Shipments**  **Broken Down**  **by**

**Figure 3.2.7.**  **Models of**  **Capacitor­Start, Induction­Run**  **Small Electric**  **Motors Broken**  **Down by** 

**Figure 3.2.8.**  **Efficiency as**  **a Function**  **of Horsepower**  **for Capacitor­Start,**  **Induction­Run Small** 

**Figure 3.2.9.**  **Capacitor­Start, Capacitor­Run**  **Small Electric**  **Motor Shipments**  **Broken Down**  **by**

**Figure 3.2.10.**  **Capacitor­Start, Capacitor­Run**  **Small Electric**  **Motor Shipments**  **Broken Down**  **by**

**Figure 3.2.11.**  **Models of**  **Capacitor­Start, Capacitor­Run**  **Small Electric**  **Motors Broken**  **Down by**  **Figure 3.2.2.**  **Polyphase Small**  **Electric Motor**  **Shipments Broken**  **Down by**  **Horsepower**

**........... 15** 

**Figure 3.2.3.**  **Models of**  **Polyphase Small**  **Electric Motors**  **Broken Down**  **by Horsepower** 

**.......... 15** 

**Figure 3.2.4.**  **Efficiency as**  **Function of**  **Horsepower for**  **Polyphase Small**  **Electric Motors** 

**......... 16** 

**Pole Configuration** 

**........................................................................................................................ 16** 

**Horsepower**

**.......................................... .........................................................................................**  **17**

**Horsepower**

**.......................................... .........................................................................................**  **17**

**Electric Motors** 

**..................................... .........................................................................................**  **18**

**Pole Configurations** 

**...................................................................................................................... 18** 

**Horsepower**

**.......................................... .........................................................................................**  **19**

**Horsepower**

**.......................................... .........................................................................................**  **19**

**3­ii**CHAPTER 3. MARKET AND TECHNOLOGY ASSESSMENT

3. 1 INTRODUCTION

**This chapter**  **details the**  **market and**  **technology assessment**  **that the**  **U.S. Department**  **of**

**Energy (DOE)**  **conducted in**  **support of**  **its energy**  **conservation standards**  **rulemaking for**  **small**

**electric motors.**  **The small**  **electric motors**  **rulemaking was**  **initiated under**  **the Energy**  **Policy and** 

**Conservation Act**  **(EPCA), Public**  **Law 94–163,**  **as amended,**  **by the**  **Energy Policy**  **Act of**  **1992**

**(EPACT 1992),**  **Public Law**  **102–486. The**  **statute requires**  **that, if**  **DOE were**  **to adopt**  **energy**

**conservation standards**  **for small**  **electric motors,**  **they apply**  **would become**  **effective to**  **small**

**electric motors**  **manufactured five**  **years after**  **the publication**  **date of**  **the final**  **rule. a** 

**This chapter**  **consists of**  **two major**  **sections, the**  **market assessment**  **and the**  **technology**

**assessment. The**  **goal of**  **the market**  **assessment is**  **to develop**  **a qualitative**  **and quantitative** 

**characterization of**  **the small**  **electric motors**  **industry. This**  **assessment characterizes**  **the market** 

**structure based**  **on publicly**  **available information**  **as well**  **as data**  **supplied by**  **manufacturers and** 

**other interested**  **parties. Issues**  **include manufacturer**  **characteristics and**  **market shares,**  **existing**

**regulatory and**  **non­regulatory efficiency**  **improvement programs,**  **equipment classes,**  **and trends** 

**in market**  **and equipment**  **characteristics. The**  **goal of**  **the technology**  **assessment is**  **to develop**  **a**

**preliminary list**  **of technology**  **options that**  **manufacturers can**  **use to**  **improve the**  **efficiency of** 

**small electric**  **motors.**

3. 2 MARKET ASSESSMENT

**This section**  **addresses the**  **scope of**  **the rulemaking,**  **identifies potential**  **equipment**

**classes, estimates**  **national shipments**  **of small**  **electric motors,**  **and the**  **market shares**  **of small** 

**electric motor**  **manufacturers. This**  **section also**  **addresses typical**  **equipment lifetimes**  **and**

**market performance**  **data, and**  **discusses regulatory**  **and non­regulatory**  **programs that**  **apply to** 

**small electric**  **motors.**

3. 2.1 Small Electric Motor Definition

**One of**  **the key**  **documents that**  **relates to**  **the scope**  **of coverage**  **for small**  **electric motors**  **is**

**the National**  **Electrical Manufacturers**  **Association (NEMA)**  **Standards Publication**  **MG 1**  **for**

**Motors and**  **Generators. NEMA**  **drafted and**  **maintains the**  **MG 1**  **document, most**  **recently**

**revised in**  **November 2007**  **as MG**  **1–2006 Revision**  **1. MG**  **1 assists**  **users in**  **the correct**  **selection**

**and application**  **of electric**  **motors and**  **generators. MG**  **1 provides**  **practical information**  **to small** 

**a A**  **Final Rule**  **for Small**  **Electric Motors**  **is scheduled**  **to be**  **published by**  **February 28,**  **2010. Under**  **section**

**346(b)(3), any**  **standard for**  **small electric**  **motors “shall**  **apply to**  **small electric**  **motors manufactured**  **60 months**  **after**

**the date**  **such rule**  **is published**  **or, in**  **the case**  **of small**  **electric motors**  **which require**  **listing or**  **certification by**  **a**

**nationally recognized**  **test laboratory,**  **84 months**  **after such**  **date.” (42**  **U.S.C. 6317(b)(3))**  **Thus, if**  **DOE does**  **adopt**

**energy conservation**  **standards for**  **small electric**  **motors, it**  **is anticipated**  **that these**  **standards would**  **apply to**  **small**

**electric motors**  **manufactured after**  **February 28,**  **2015 and**  **February 28,**  **2017, respectively.** 

**3­1 electric**  **motor manufacturers**  **and users**  **concerning the**  **construction, testing,**  **performance, and** 

**safety of**  **alternating current**  **(AC) and**  **direct current**  **(DC) motors**  **and generators.** 

**The term**  **“small electric**  **motor” is**  **defined in**  **the statute,**  **and thus,**  **the scope**  **of coverage** 

**for this**  **rulemaking is**  **determined by**  **this statutory**  **definition. Section**  **340(13)(G) of**  **EPCA**

**b defines**  **the term**  **“small electric**  **motor” to**  **mean “a**  **NEMA general­purpose**  **alternating current** 

**single­speed induction**  **motor, c**  **built in**  **a two­digit**  **frame number**  **series d**  **in accordance**  **with**

**NEMA Standards**  **Publication MG**  **1–1987.” (42**  **U.S.C. 6311(13)(G))**  **Such motors**  **include**

**single­phase, capacitor­start**  **induction­run (CSIR),**  **capacitor­start capacitor­run**  **(CSCR), and** 

**polyphase motors.**  **DOE addresses**  **the scope**  **of small**  **electric motors**  **covered in**  **the sections**  **that**

**follow, noting**  **that today’s**  **scope is**  **slightly narrower**  **than what**  **DOE considered**  **for the** 

**determination analysis.**  **See**

**http://www1.eere.energy.gov/buildings/appliance_standards/commercial/small_electric_motors.h**

**tml.**

**Section 346(b)(3)**  **of EPCA**  **(42 U.S.C.**  **6317(b)(3)) requires**  **that a**  **standard prescribed**  **for**

**small electric**  **motors shall**  **not apply**  **to any**  **small electric**  **motor that**  **is a**  **component of**  **a covered** 

**product under**  **section 322(a)**  **of EPCA**  **(42 U.S.C.**  **6292(a)) or**  **of covered**  **equipment under** 

**section 340**  **of EPCA.**  **(42 U.S.C.**  **6311) Such**  **products and**  **equipment include,**  **for example,** 

**residential air**  **conditioners and**  **heat pumps,**  **furnaces, refrigerators**  **and freezers,**  **clothes washers** 

**and dryers,**  **commercial packaged**  **air­conditioning and**  **heating equipment,**  **and commercial** 

**refrigeration equipment.**  **Accordingly, the**  **analysis does**  **not include**  **small electric**  **motors**

**incorporated into**  **residential and**  **commercial products**  **either covered**  **or specifically**  **excluded by** 

**statute.**

**On July**  **10, 2006,**  **DOE published**  **in the**  Federal Register **its determination**  **that energy** 

**conservation standards**  **for small**  **electric motors**  **appear to**  **be technologically**  **feasible and** 

**economically justified,**  **and would**  **result in**  **significant energy**  **savings. 71**  **FR 38807.**  **A key** 

**issue that**  **arose early**  **in the**  **analytical process**  **was interpretation**  **of the**  **EPCA definition**  **of a** 

**small electric**  **motor and**  **precisely which**  **motors are**  **covered. The**  **EPCA definition**  **identifies**

**several key**  **terms that**  **are defined**  **in NEMA**  **MG 1–1987,**  **such as**  **general purpose**  **and two­digit** 

**frame size.**  **Thus, EPCA’s**  **definition of**  **a small**  **electric motor**  **is tied**  **to NEMA**  **MG1–1987**

**terminology and**  **performance requirements**  **established for**  **(1) general­purpose**  **alternating**

**current motors,**  **(2) various**  **categories of**  **induction motors,**  **and (3)**  **the definition**  **of two­digit** 

**b “General­purpose**  **alternating current”**  **is a**  **term that**  **NEMA uses**  **for alternating­current**  **motors that**  **are not** 

**designed with**  **a specific**  **application in**  **mind.**

**An induction**  **motor converts**  **electrical power**  **into rotational**  **mechanical power.**  **It depends**  **on electromagnetic** 

**induction for**  **its operation**  **and has**  **one or**  **more component**  **members capable**  **of rotary**  **movement.**

**d The**  **terms “two­digit**  **frame number**  **series” and**  **“frame size”**  **refer to**  **a motor’s**  **standard system**  **of numbers**  **in**

**combination with**  **letters for**  **designating the**  **size and**  **mounting dimensions**  **of a**  **motor, according**  **to NEMA** 

**Standards Publication**  **MG1, “Motors**  **and Generators.”**  **In the**  **case of**  **small motors,**  **frame size**  **is the**  **“D” dimension** 

**in inches**  **multiplied by**  **16. The**  **“D” dimension**  **is measured**  **from the**  **centerline of**  **the shaft**  **to the**  **bottom of**  **the**

**mounting feet.**  **For example,**  **a 48­frame**  **motor would**  **have a**  **“D” dimension**  **of 3.00**  **inches (16**  **x 3.00** 

**= 48).**  **Such**

**standard dimensions**  **are essential**  **to fitting**  **a motor**  **to the**  **equipment it**  **drives and**  **for interchangeability**  **among**

**motors.**

**3­2 c** **frame size.**  **In the**  **following subsections,**  **DOE addresses**  **elements of**  **the definition**  **of “small** 

**electric motor”**  **that need**  **clarification.**

3. 2.1.1 General­Purpose Alternating­Current Motor

**Two elements**  **in the**  **statutory definition**  **of small**  **electric motors,**  **which derive**  **from**

**NEMA MG1–1987,**  **are “general­purpose”**  **and “alternating­current.”**  **Paragraph MG1–1.05**  **sets**

**forth the**  **definition:**

**A general­purpose**  **alternating­current motor**  **is an**  **induction motor,**  **rated 200**  **horsepower**

**and less,**  **which incorporates**  **all of**  **the following:**  **(1) open**  **construction e** 

**, (2)**  **rated**

**continuous duty,**  **(3) service**  **factor in**  **accordance with**  **MG 1­12.47,**  **and (4)**  **Class A** 

**insulation system**  **with a**  **temperature rise**  **as specified**  **in MG**  **1­12.42 for**  **small electric** 

**motors or**  **Class B**  **insulation system**  **with a**  **temperature rise**  **as specified**  **in MG**  **1­12.43**

**for medium**  **motors. It**  **is designed**  **in standard**  **ratings with**  **standard operating** 

**characteristics and**  **mechanical construction**  **for use**  **under usual**  **service conditions**  **without**

**restriction to**  **a particular**  **application or**  **type of**  **application.**

**The four**  **criteria that**  **NEMA used**  **in MG**  **1­1987 to**  **define a**  **general­purpose alternating** 

**current motor**  **are open**  **construction, continuous**  **duty, service**  **factor, and**  **a Class**  **A insulation** 

**system.**

**Open construction**  **refers to**  **the type**  **of enclosure**  **that houses**  **the motor.**  **An open** 

**construction enclosure**  **allows outside**  **air to**  **pass through**  **and cool**  **the motor**  **when it**  **is operating.** 

**Electric motors**  **are also**  **manufactured with**  **closed construction**  **housings, which**  **do not**  **circulate**

**external air**  **for cooling.** 

**A motor**  **rated for**  **continuous duty**  **can operate**  **a driven**  **machine indefinitely**  **at the**  **rated**

**load, speed,**  **and temperature**  **without injury**  **to the**  **motor. The**  **statutory language**  **directs DOE**  **to**

**cover and**  **evaluate general­purpose**  **alternating­current motors,**  **which are**  **rated for**  **continuous**

**duty (as**  **opposed to**  **intermittent duty).**  **Therefore, in**  **this rulemaking**  **analysis, DOE**  **proposes to** 

**consider only**  **those motors**  **rated for**  **continuous duty.** 

**MG 1–1987**  **defines general­purpose**  **alternating­current motors**  **as having**  **a service**  **factor**

**in accordance**  **with MG**  **1–12.47. The**  **service factor**  **is a**  **measure of**  **the overload**  **capacity at** 

**which a**  **motor can**  **operate without**  **damage, while**  **operating normally**  **within the**  **correct voltage** 

**tolerances. The**  **rated horsepower**  **(hp) multiplied**  **by the**  **service factor**  **gives that**  **overload**

**capacity. For**  **example, a**  **1­horsepower motor**  **with a**  **1.25 service**  **factor can**  **operate at**  **1.25**

**horsepower (1**  **horsepower x**  **1.25 service**  **factor). NEMA**  **MG 1–1987**  **requires that**  **the service** 

**factor for**  **general­purpose alternating­current**  **motors be**  **in accordance**  **with MG**  **1–12.47. (See** 

**e NEMA**  **MG1–1987 defines**  **each of**  **the following**  **motors, in**  **part, as**  **“an open**  **machine”: drip­proof,**  **splash­proof,**

**semi­guarded, guarded,**  **dripproof guarded,**  **open externally**  **ventilated, open**  **pipe­ventilated, and**  **weather­protected**

**(Type I**  **and Type**  **II).**

**3­3 Table**  **3.2.1.) Therefore,**  **in this**  **rulemaking, DOE**  **proposes to**  **cover only**  **those small**  **electric**

**motors that**  **meet the**  **NEMA service**  **factor requirements.** 

Table 3.2.1. National Electrical Manufacturers Association Standard MG1–1987 Service

Factor Requirements of Small Electric Motors

Horsepower Required Service Factors by Synchronous Speed (rpm)

3, 600 1, 800 1, 200 900

1/20 **1. 4**  **1. 4**  **1. 4**  **1. 4** 

1/12 **1. 4**  **1. 4**  **1. 4**  **1. 4** 

1/8 **1. 4**  **1. 4**  **1. 4**  **1. 4** 

1/6 **1. 35**  **1. 35**  **1. 35**  **1. 35** 

1/4 **1. 35**  **1. 35**  **1. 35**  **1. 35** 

1/3 **1. 35**  **1. 35**  **1. 35**  **1. 35** 

1/2 **1. 25**  **1. 25**  **1. 25** 

**­**

3/4 **1. 25**  **1. 25** 

**­ ­** 

1 **1. 25** 

**­ ­**  **­**

**The MG**  **1–1987 definition**  **of “general­purpose**  **alternating­current motor,”**  **in part** 

**identifies a**  **a small**  **electric motor**  **as one**  **that incorporates**  **a Class**  **A insulation**  **system with**  **a**

**temperature rise**  **as specified**  **in MG1–12.42.**  **This paragraph**  **establishes the**  **maximum**

**temperature rise**  **of the**  **various parts**  **of the**  **motor, over**  **a 40°C**  **ambient temperature.**  **For**

**example, the**  **temperature rise**  **of the**  **windings of**  **a small**  **electric motor**  **with open**  **construction**

**and a**  **Class A**  **insulation system**  **shall not**  **exceed 60°C;**  **if the**  **motor’s service**  **factor is**  **greater**

**than 1.15,**  **it shall**  **not exceed**  **70°C. Although**  **small electric**  **motors can**  **be manufactured**  **with**

**Class B,**  **Class F,**  **or Class**  **H insulation**  **systems, DOE**  **proposes to**  **cover only**  **those small**  **electric**

**motors with**  **Class A**  **insulation systems.** 

**Lastly, MG1–1987**  **requires that**  **a general­purpose**  **alternating­current motor**  **be designed** 

**in standard**  **ratings with**  **standard operating**  **characteristics and**  **mechanical construction**  **for use** 

**under usual**  **service conditions**  **without restriction**  **to a**  **particular application**  **or type**  **of**

**application. This**  **provision is**  **consistent with**  **the definition**  **of “general­purpose**  **motor” under** 

**section 431.12**  **of Title**  **10 of**  **the Code**  **of Federal**  **Regulations, Part**  **431 (10**  **CFR Part**  **431).**

**Essentially, both**  **MG1–1.05 and**  **10 CFR**  **431.12 require**  **general­purpose motors**  **to meet** 

**“standard ratings,”**  **which are**  **generally understood**  **to mean**  **any performance**  **or physical** 

**characteristics established**  **as a**  **rule or**  **model by**  **authority, custom,**  **or general**  **consent. The** 

**NEMA Standard**  **MG1 is**  **based on**  **general consent,**  **meaning that**  **NEMA members**  **who**

**manufacture motors**  **and generators**  **covered in**  **MG1 can**  **vote to**  **approve the**  **document.**

**For small**  **electric motors,**  **examples of**  **standard ratings**  **include minimum**  **breakdown**

**torque (see**  **NEMA MG1–12.32.1)**  **and minimum**  **locked­rotor torque**  **(see NEMA**  **MG1–**

**3­4 12.32.2).**  **Such requirements**  **limit the**  **scope of**  **covered small**  **electric motors.**  **For example,**  **the**

**breakdown torques**  **of many**  **shaded­pole and**  **permanent­split capacitor**  **motors do**  **not fall**  **within**

**the breakdown**  **torque ranges**  **of MG1**  **Table 10–5.**  **Section 12.32.2**  **of MG**  **1­1987 requires**  **that**

**the locked­rotor**  **torque shall**  **be no**  **less than**  **the values**  **presented in**  **Table 3.2.2.** 

Table 3.2.2. Minimum Locked­Rotor Torque, Ounce­Feet*

Horsepower 60­Hz Synchronous Speed

(RPM) 50­Hz Synchronous Speed

(RPM)

**3, 600** 

**3,450 1,**  **800**

**1,725 1,**  **200**

**1,140 3,**  **000**

**2,850 1,**  **500**

**1,425 1,**  **000**

**950**

1/8

**­ 24**  **32**

**­ 29**  **39**

1/6 **15  ** 33** **43 18**  **39 51** 

1/4 **21 46**  **59 25**  **55 70** 

1/3 **26 57**  **73 31**  **69 88** 

1/2 **37 85**  **100 44**  **102 120** 

3/4 **50 119** 

**­ 60**  **143**

**­**

1 **61**

**­ ­**  **73**

**­ ­** 

***** **On the**  **high voltage**  **connection of**  **dual voltage**  **motors, minimum**  **locked­rotor torques**  **up to**  **10 percent**  **less than** 

**these values**  **may be**  **expected.**

****** **Each value**  **in this**  **table depicts**  **the ounce­feet**  **of locked**  **rotor torque**  **for this**  **combination of**  **horsepower and** 

**synchronous speed.**  **For this**  **particular combination**  **(** i.e.

**, 1/6**  **horsepower with**  **a speed**  **between 3,450**  **and 3,600** 

**rpm), manufacturers**  **must ensure**  **that the**  **motor has**  **at least**  **15 ounce­feet**  **of locked**  **rotor torque**  **to meet**  **this**

**requirement of**  **NEMA MG1–1987.** 

**Of the**  **motors satisfying**  **the frame­size**  **requirement of**  **the EPCA**  **definition of**  **“small**

**electric motor”**  **and “built**  **in a**  **two­digit frame**  **number series**  **in accordance**  **with NEMA** 

**Standards Publication**  **MG 1–1987,”**  **only a**  **subset incorporates**  **the other**  **performance**

**requirements of**  **a general­purpose**  **motor under**  **NEMA MG**  **1–1987, paragraph**  **1.05. Among** 

**single­phase motors**  **with a**  **two­digit frame**  **size, DOE**  **found that**  **only capacitor­start**  **motors–**

**including capacitor­start**  **induction­run, and**  **capacitor­start capacitor­run**  **motors–can meet**  **the**

**torque requirements**  **for NEMA**  **general­purpose motors.**  **Among three­phase**  **small electric** 

**motors, only**  **non­servo motors**  **can meet**  **the NEMA**  **performance requirements**  **for general** 

**purpose motors.**  **Hence, DOE’s**  **analysis only**  **covers the**  **capacitor­start categories**  **of single** 

**phase motors**  **and three­phase**  **small electric**  **motors.**

3. 2.1.2 Categories of Induction Motors

**The statutory**  **definition also**  **requires that**  **a small**  **electric motor**  **be an**  **“alternating current** 

**single­speed induction**  **motor” built**  **in accordance**  **with NEMA**  **MG1–1987. DOE**  **identified six** 

**categories of**  **alternating current**  **single­speed induction**  **motors: split­phase,**  **f shaded­pole,**  **g**

**f A**  **split­phase motor**  **is a**  **single­phase induction**  **motor equipped**  **with an**  **auxiliary winding**  **displaced in**  **magnetic**

**position from,**  **and connected**  **parallel to,**  **the main**  **winding. Unless**  **otherwise specified,**  **DOE assumed**  **that the** 

**3­5 capacitor­start**  **(both CSIR**  **h and**  **CSCR i**  **), permanent­split**  **capacitor (PSC),**  **j and**  **polyphase. k**  **In**

**the discussion**  **that follows,**  **DOE explains**  **its review**  **of these**  **six induction**  **motor categories**  **and**

**its preliminary**  **conclusion that**  **the CSIR,**  **CSCR, and**  **polyphase motors**  **are the**  **only three** 

**categories which**  **are covered**  **under EPCA.** 

**DOE eliminated**  **split­phase, PSC,**  **and shaded­pole**  **motors from**  **consideration because** 

**they are**  **not designed**  **as and**  **do not**  **meet the**  **performance requirements**  **of general­purpose** 

**motors. Split­phase**  **motors are**  **designed for**  **specific purposes**  **and applications,**  **and generally** 

**for applications**  **that are**  **short­time rated.**  **Also, split­phase**  **motors do**  **not meet**  **the breakdown** 

**torque requirements**  **or the**  **locked­rotor torque**  **requirements while**  **simultaneously maintaining** 

**the locked­rotor**  **current requirements**  **that have**  **been established**  **in NEMA**  **for general­purpose** 

**motors. In**  **some cases,**  **split­phase motors**  **are components**  **of products**  **covered under**  **EPCA**

**sections 322(a)**  **and 340,**  **42 U.S.C.**  **6292(a) and**  **6311, respectively**  **and are**  **otherwise excluded** 

**from coverage**  **by statute.**  **(42 U.S.C.**  **6317(b)(3)) Similarly,**  **PSC motors**  **used in**  **fans, business** 

**machines, and**  **hermetic motor**  **compressors do**  **not meet**  **the torque**  **requirements for**  **NEMA**

**general­purpose motors.**  **Shaded­pole motors**  **that are**  **generally intended**  **for intermittent** 

**operation in**  **applications such**  **as rotisseries,**  **fans, humidifiers,**  **small business**  **machines,**

**advertising machines,**  **copiers, vending**  **machines and**  **advertising displays**  **also do**  **not meet**  **the**

**requirements. These**  **shaded­pole motors**  **tend to**  **have low**  **efficiency ratings**  **(** i.e.

**, less**  **than 50** 

**percent) and**  **are sold**  **in high**  **volume. However,**  **DOE believes**  **that because**  **PSC and**  **shaded**

**pole motors**  **do not**  **meet the**  **performance characteristics**  **for NEMA**  **general­purpose motors,** 

**which are**  **required under**  **EPCA section**  **340(13)(G), 42**  **U.S.C. 6311(13)(G),**  **and identified**  **in**

**NEMA MG1–1.05,**  **they are**  **not covered**  **categories of**  **induction motors.** 

**The remaining**  **categories of**  **small electric**  **motors include**  **CSIR, CSCR,**  **and polyphase.** 

**In view**  **of its**  **July 2006**  **determination (71**  **FR 38799),**  **DOE re­examined**  **the standard** 

**performance characteristics,**  **construction specifications,**  **and ratings**  **for these**  **three motor** 

**categories. DOE**  **concluded that**  **they meet**  **the EPCA**  **requirements for**  **small electric**  **motors.**

**Furthermore, CSIR,**  **CSCR, and**  **polyphase small**  **electric motors**  **are manufactured**  **in two­digit** 

**frame sizes,**  **can be**  **rated for**  **continuous­duty applications,**  **and can**  **meet other**  **performance**

**requirements for**  **general­purpose motors,**  **including the**  **torque requirements**  **under NEMA**  **MG1–**

**1987, paragraph**  **12.32. Therefore,**  **DOE will**  **address three**  **categories of**  **small electric**  **motors in** 

**today’s rulemaking:**  **single­phase CSIR,**  **single­phase CSCR,**  **and polyphase.** 

**auxiliary circuit**  **is open**  **when the**  **motor attains**  **a predetermined**  **speed. The**  **term “split­phase**  **motor” describes**  **a**

**motor to**  **be used**  **without impedance**  **other than**  **that offered**  **by the**  **motor windings**  **themselves.**

**g A**  **shaded­pole motor**  **is a**  **single­phase induction**  **motor provided**  **with an**  **auxiliary short­circuited**  **winding or** 

**windings displaced**  **in magnetic**  **position from**  **the main**  **winding.**

**h A**  **capacitor­start, induction­run**  **motor is**  **a single­phase**  **motor with**  **a main**  **winding arranged**  **for direct**  **connection**

**to a**  **source of**  **power and**  **an auxiliary**  **winding connected**  **in series**  **with a**  **capacitor. The**  **motor has**  **a capacitor**  **phase,**

**which is**  **in the**  **circuit only**  **during the**  **starting period.** 

**A capaci**  **tor­start, capacitor­run**  **motor is**  **a single­phase**  **motor with**  **different values**  **of effective**  **capacitance for**  **the**

**starting and**  **running conditions.** 

**j A**  **permanent­split capacitor**  **motor is**  **another category**  **of single­phase**  **motor that**  **has the**  **same value**  **of capacitance** 

**for both**  **starting and**  **running conditions.** 

**k A**  **polyphase motor**  **is an**  **electric motor**  **that uses**  **the phase**  **changes of**  **the electrical**  **supply to**  **induce a**  **rotational**

**magnetic field**  **and thereby**  **supply torque**  **to the**  **rotor.**

**3­6 i** 3.2.1.3 Frame Sizes and Metric Equivalents

**Another element**  **in the**  **statutory definition**  **is that**  **a small**  **electric motor**  **is “built**  **in a**  **two**

**digit frame**  **number series**  **in accordance**  **with NEMA**  **Standards Publication**  **MG1–1987.”**

**NEMA MG1–1987**  **establishes a**  **system of**  **numbers and**  **letters for**  **designating motor**  **frames.**

**The frame**  **number for**  **a small**  **electric motor**  **is determined**  **by measuring**  **the distance**  **in inches** 

**between the**  **centerline of**  **the shaft**  **to the**  **bottom of**  **the mounting**  **feet multiplied**  **by 16.**  **The two** 

**digit frame**  **series encompasses**  **NEMA frame**  **sizes 42,**  **48, and**  **56. Two­digit**  **NEMA frames** 

**have standard**  **dimensions and**  **tolerances specified**  **in NEMA**  **Standard MG1­1987** 

**paragraphs11.31 and**  **11.34, which**  **are necessary**  **for mounting**  **and interchangeability**  **among**

**general­purpose applications.** 

**NEMA MG1–1987**  **only assigns**  **standard dimensions**  **to 42,**  **48, and**  **56 frame**  **motors.**

**However, certain**  **other non­standard**  **frame sizes,**  **such as**  **a 66**  **frame size,**  **are manufactured**  **and**

**sold. While**  **“66” is**  **a two­digit**  **frame size,**  **it does**  **not appear**  **in NEMA**  **MG1–1987.**

**Consequently, a**  **66­frame motor**  **may not**  **be covered**  **under the**  **EPCA definition**  **of “small** 

**electric motor.”**  **Furthermore, DOE**  **believes that**  **non­standard, two­digit**  **frames sizes**  **(i.e., other** 

**than 42,**  **48, and**  **56) fall**  **outside the**  **scope of**  **the rulemaking**  **for small**  **electric motors.**  **Such non** 

**standard frame**  **sizes are**  **likely to**  **be definite­purpose**  **or special­purpose**  **motors that**  **are not**  **used**

**in general­purpose**  **applications.**

**DOE is**  **concerned about**  **metric equivalents**  **for the**  **two­digit NEMA**  **frame series,**  **the**

**uncertainty about**  **cross­references, and**  **the potential**  **issues with**  **imports of**  **small electric**  **motors,**

**whether manufactured**  **alone or**  **as a**  **component of**  **another piece**  **of equipment.** 

**EPCA section**  **340(13)(F), as**  **amended by**  **EPCA 1992,**  **42 U.S.C.**  **6311(13)(F), defines** 

**small electric**  **motors in**  **terms of**  **“NEMA Standards**  **Publication MG1–1987,”**  **whose**

**construction and**  **rating system**  **uses English**  **units of**  **measurement and**  **output ratings**  **in**

**l horsepower.**  **In contrast,**  **general­purpose electric**  **motors manufactured**  **outside the**  **United**

**States and**  **Canada are**  **defined and**  **described with**  **reference to**  **the International**  **Electrotechnical**

**Commission (IEC)**  **Standard 60034–1**  **series, “Rotating**  **electrical machines,”**  **which use**  **different**

**terminology and**  **criteria than**  **EPCA. The**  **performance attributes**  **of these**  **IEC motors**  **are rated** 

**pursuant to**  **IEC Standard**  **60034–1, “Rating**  **and performance,”**  **which uses**  **metric units**  **of**

**measurement, a**  **different construction**  **and rating**  **system than**  **NEMA MG1–1987,**  **and output** 

**ratings in**  **kilowatts instead**  **of output**  **ratings in**  **horsepower. Standards**  **exist, such**  **as the**  **Institute**

**of Electrical**  **and Electronics**  **Engineers Standard**  **112, which**  **define the**  **relationship between** 

**horsepower and**  **watts or**  **kilowatts. Further,**  **10 CFR**  **431.12 (2008)**  **defines “electric**  **motor” in** 

**terms of**  **NEMA and**  **IEC equivalents,**  **and 10**  **CFR 431.25**  **provides a**  **table of**  **horsepower and** 

**kilowatt equivalent**  **ratings, which**  **DOE views**  **as a**  **precedent for**  **similar treatment**  **of small** 

**electric motors.** 

**Although the**  **statutory definition**  **of small**  **electric motor**  **does not**  **address metric**  **or**

**kilowatt­rated motors,**  **DOE believes**  **that EPCA**  **covers any**  **motor that**  **is equivalent**  **to or**  **can be** 

**The Energy**  **Independence and**  **Security Act**  **of 2007**  **(EISA 2007),**  **renumbered EPCA**  **section 340(13)(F)** 

**(42 U.S.C.**  **6311(13)(F)) to**  **be section**  **340(13)(G) (42**  **U.S.C. 6311(13)(G)).**  **There was**  **no change**  **in the**  **language.**

**3­7 l** **used as**  **a substitute**  **for a**  **covered small**  **electric motor.**  **Generally, IEC**  **metric or**  **kilowatt**

**equivalent motors**  **can perform**  **the identical**  **functions of**  **small electric**  **motors and**  **provide**

**comparable rotational**  **mechanical power**  **to the**  **same machines**  **or equipment.**  **In other**  **words,**

**IEC metric**  **or kilowatt­equivalent**  **motors can**  **be interchanged**  **with small**  **electric motors.**  **A**

**given commercial**  **central air**  **conditioner, for**  **example, could**  **operate with**  **either an**  **IEC motor**  **or**

**NEMA motor**  **with little**  **or no**  **effect on**  **performance. Therefore,**  **DOE interprets**  **EPCA to**  **mean**

**that a**  **“small electric**  **motor” is**  **any motor**  **that is**  **identical or**  **equivalent to**  **a motor**  **constructed**

**and rated**  **in accordance**  **with NEMA**  **MG1 and**  **covered by**  **the statute.**  **Otherwise, placing** 

**energy efficiency**  **requirements on**  **NEMA small**  **electric motors,**  **but not**  **on equivalent**  **IEC or** 

**kilowatt­rated small**  **electric motors,**  **could give**  **preferential treatment**  **to the**  **latter, should**  **DOE**

**establish minimum**  **energy conservation**  **standards for**  **the NEMA**  **small electric**  **motors but**  **not**

**the IEC**  **equivalent motors.** 

3. 2.1.4 Motor Enclosure

**DOE examined**  **the definition**  **of “general­purpose**  **alternating­current motor”**  **as it**  **appears**

**in NEMA**  **Standard MG1–1987.**  **It explicitly**  **states that**  **a general­purpose**  **alternating­current**

**motor incorporates**  **“open construction.”**  **Later versions**  **of NEMA**  **Standard MG1**  **revised the** 

**definition and**  **expanded it**  **to incorporate**  **open or**  **enclosed construction.**  **However, this**  **is not**  **the**

**case with**  **the EPCA­directed**  **definition. Therefore,**  **DOE interprets**  **the EPCA**  **definition of**  **a**

**small electric**  **motor to**  **cover only**  **open construction.**  **This is**  **in contrast**  **to and**  **supersedes**

**DOE’s initial**  **understanding of**  **covered small**  **electric motors.**  **DOE initially**  **included totally** 

**enclosed motors**  **in the**  **scope of**  **its determination**  **analysis.**

**DOE considered**  **poly­ and single­phase**  **motors, including**  **non­servo three­phase**  **motors;**

**capacitor­start, induction­run**  **motors; and**  **capacitor­start, capacitor­run**  **motors. Only**  **those**

**motors that**  **are built**  **with an**  **open construction**  **are applicable.**  **Horsepower ranges**  **and pole** 

**configurations are**  **also important**  **characteristics of**  **covered motors.**  **These topics**  **are discussed** 

**in section**  **3.2.3.**

3. 2.2 Small Electric Motor Nameplates and Terminology

**The National**  **Fire Protection**  **Association (NFPA)**  **Standard 70,**  **“National Electrical** 

**Code,” article**  **430.7, and**  **NEMA MG**  **1 paragraph**  **10.39 prescribe**  **a consistent**  **set of**  **required**

**information that**  **is reported**  **on all**  **motor nameplates.**  **This information**  **enables a**  **motor user**  **to**

**purchase and**  **install a**  **motor that**  **is appropriate**  **for a**  **particular application.**  **The NFPA**  **70 and** 

**MG 1**  **each require**  **that an**  **electric motor**  **nameplate be**  **marked with**  **information that**  **includes,**

**but is**  **not limited**  **to:**

• **manufacturer's name;** 

• **frame designation;** 

• **rated voltage;** 

• **rated full­load**  **current;**

• **rated frequency;** 

• **number of**  **phases;**

• **rated full­load**  **speed;**

**3­8**• **rated temperature**  **rise or**  **the insulation**  **system class**  **and rated**  **ambient temperature;** 

• **rated horsepower;** 

• **time rating;** 

• **code letter**  **for locked­rotor**  **amperes; and** 

• **thermal protection.** 

**In the**  **following table,**  **DOE provides**  **a brief**  **description of**  **each of**  **the fields**  **that NFPA** 

**70 or**  **NEMA Standard**  **MG 1**  **require on**  **the motor**  **nameplate.**

**3­9**Table 3.2.3. Required Small Electric Motor Nameplate Information

**Frame**

**Designation Frame**  **size numbers**  **represent standardized**  **designations for**  **size and** 

**dimensions. For**  **small electric**  **motors, the**  **frame sizes**  **are two**  **digits,**

**determined by**  **the shaft**  **height of**  **the motor**  **from the**  **bottom of**  **the base**  **in**

**sixteenths of**  **an inch.**  **For example,**  **a 56­frame**  **motor would**  **have a**  **shaft**

**height (“D”**  **dimension) of**  **56/16 of**  **an inch,**  **or 3.5**  **inches. For**  **metric**

**motors, the**  **frame size**  **is also**  **the shaft**  **height of**  **the motor**  **from the**  **bottom**

**of the**  **base, but**  **the height**  **is noted**  **in millimeters**  **rather than**  **sixteenths of**  **an**

**inch.**

**Rated Voltage**  **Rated voltage**  **is the**  **design voltage**  **at which**  **an electric**  **motor will**  **yield**

**optimal performance.**  **In general,**  **motors should**  **be capable**  **of operating** 

**within a**  **20% band**  **of the**  **rated voltage,**  **10% above**  **to 10%**  **below.**

**Rated Full­Load** 

**Amperage The**  **rated full­load**  **amperage represents**  **the amperage**  **consumption when**  **the**

**motor reaches**  **full­load torque.**  **The value**  **is determined**  **by testing**  **a sample** 

**of motors,**  **and is**  **usually rounded**  **up to**  **allow for**  **slight variations**  **in**

**manufacturing that**  **may increase**  **the full­load**  **amperes. The**  **purpose of**  **the**

**full­load amperes**  **is to**  **enable appropriate**  **sizing of**  **power supply**  **wiring and** 

**any overload**  **protection devices.** 

**Frequency For**  **the North**  **American market,**  **motors are**  **designed to**  **operate on** 

**alternating current**  **at 60**  **Hertz (cycles**  **per second).** 

**Phase Single­phase**  **and three­phase**  **motors are**  **available in**  **the United**  **States.**

**Rated Full­Load** 

**Speed The**  **rated full­load**  **speed is**  **the approximate**  **rotations per**  **minute of**  **the**

**motor under**  **full­load conditions**  **at a**  **specified voltage**  **and frequency.**  **The**

**full­load speed**  **is typically**  **95% to**  **99% of**  **the no­load**  **speed.**

**Insulation Class** 

**and Rated** 

**Ambient**

**Temperature Insulation**  **class and**  **allowable maximum**  **ambient temperature**  **denote the** 

**operating parameters**  **of an**  **electric motor,**  **which directly**  **relates to**  **motor**

**operating life.**  **The maximum**  **temperature (**  i.e.

**, hot**  **spot) is**  **a combination**  **of**

**motor design**  **and ambient**  **temperature.**

**Rated**

**Horsepower Rated**  **horsepower is**  **a measure**  **of how**  **much work**  **a motor**  **is expected**  **to**

**perform. Horsepower**  **is based**  **on full­load**  **speed and**  **torque rating,**  **as**

**follows:**

**Horsepower (hp)** 

**= [(Motor**  **Speed) ×**  **(Torque (lb­ft))]**  **÷ 5,250.** 

**Time Rating**  **Time rating**  **states whether**  **the motor**  **is rated**  **for continuous**  **duty (24**  **hours**

**per day**  **/ 7**  **days per**  **week) or**  **certain “short­time”**  **requirements, ranging** 

**from 5**  **to 60**  **minutes. In**  **this rulemaking,**  **all small**  **electric motors**  **are rated** 

**for continuous**  **duty.**

**Locked­Rotor**

**Code Letter**  **Starting an**  **AC motor**  **creates an**  **inrush current**  **that is**  **usually several**  **times**

**greater than**  **the full­load**  **current. The**  **inrush current**  **may be**  **large enough**  **to**

**cause a**  **voltage dip**  **that affects**  **other equipment.**  **Manufacturers provide**  **the**

**inrush current**  **in motor**  **performance specification**  **sheets (“locked­rotor** 

**current”) and**  **as a**  **coded letter**  **on the**  **nameplate.**

**Manufacturer's**

**Name The**  **name of**  **the motor’s**  **manufacturer must**  **appear on**  **the nameplate.** 

**3­10 In**  **addition to**  **the above**  **information, manufacturers**  **of small**  **electric motors**  **may voluntarily** 

**include information,**  **such as**  **service factor,**  **efficiency, and**  **power factor.**  **Manufacturers usually** 

**provide such**  **information because**  **it facilitates**  **purchasing and**  **allows maintenance**  **personnel to** 

**quickly identify**  **an appropriate**  **replacement motor.** 

Table 3.2.4. Optional Small Electric Motor Nameplate Information

**Service Factor**  **This measure**  **indicates how**  **much overload**  **a motor**  **can withstand**  **when**

**operating normally**  **within the**  **correct voltage**  **tolerances. The**  **standard**

**service factor**  **for a**  **1 horsepower**  **open motor**  **with a**  **rated full**  **load speed**  **of**

**1800 revolutions**  **per minute**  **is 1.15.**  **This means**  **that such**  **a motor**  **could**

**provide 1.15**  **horsepower when**  **operated at**  **its service**  **factor. Small**  **electric**

**motors are**  **also designed**  **with higher**  **service factors,**  **such as**  **1.25 or**  **1.35.**

**Full­Load**

**Efficiency Full­load**  **efficiency is**  **a measure**  **of the**  **motor’s ability**  **to effectively**  **convert**

**electrical power**  **into mechanical**  **power and**  **is expressed**  **as a**  **percentage.**

**Power Factor**  **This value**  **is represented**  **by the**  **ratio of**  **the motor**  **load in**  **watts divided**  **by**

**voltage­amperes at**  **full load.**  **Power factor**  **varies directly**  **with loading,** 

**generally increasing**  **with load**  **percentage.**

3. 2.3 Proposed Equipment Classes

**In general,**  **DOE identifies**  **a class**  **of covered**  **equipment by**  **the type**  **of energy**  **used,**

**capacity, and**  **performance­related features**  **that affect**  **consumer utility**  **or efficiency.**  **Different**

**energy conservation**  **standards may**  **apply to**  **different equipment**  **classes. For**  **this rulemaking,** 

**DOE is**  **proposing to**  **establish 72**  **equipment classes**  **for small**  **electric motors,**  **based on**  **the**

**following criteria:**  **motor category,**  **number of**  **poles, and**  **horsepower. As**  **these motor** 

**characteristics change,**  **so does**  **the utility**  **and efficiency**  **of the**  **small electric**  **motor. The**  **lists**

**below identify**  **these three**  **characteristics. There**  **are three**  **motor categories,**  **three pole** 

**configurations, and**  **eight horsepower**  **ratings that**  **affect energy**  **consumption or**  **efficiency,**

**resulting in**  **72 combinations,**  **or equipment**  **classes.**

**1. Motor**  **Category (**  i.e.

**, type**  **of energy**  **used, start**  **and run**  **characteristics)**

• **polyphase**

• **capacitor­start, induction**  **run (CSIR)** 

• **capacitor­start, capacitor**  **run (CSCR)** 

**2. Number**  **of Poles** 

• **2**

• **4**

• **6**

**3­11 3.**  **Horsepower**

• **1/4**

• **1/3**

• **1/2**

• **3/4**

• **1**

• **1 1⁄2**

• **2**

• **3**

**First, the**  **motor category**  **depends on**  **the type**  **of energy**  **used and**  **its starting**  **and running** 

**electrical characteristics.**  **While all**  **small electric**  **motors use**  **electricity, some**  **motors operate**  **on**

**single­phase electricity**  **(which requires**  **certain additional**  **electronics for**  **creating rotational** 

**torque) while**  **others operate**  **on polyphase**  **electricity. Polyphase**  **motors do**  **not need**  **additional**

**circuitry to**  **create rotational**  **torque because**  **they use**  **the existing**  **phase difference**  **in the**  **multiple**

**phases of**  **electricity applied**  **to the**  **motor. This**  **difference impacts**  **efficiency, and**  **therefore**

**becomes a**  **factor around**  **which DOE**  **establishes a**  **separate equipment**  **class for**  **polyphase**

**motors.**

**Within single­phase**  **small electric**  **motors, there**  **are characteristics**  **which are**  **important**

**because they**  **can affect**  **the motor’s**  **utility and**  **potential for**  **improving efficiency.**  **The design** 

**feature of**  **incorporating a**  **run capacitor**  **into the**  **small electric**  **motor affects**  **the efficiency**  **of the** 

**motor, making**  **it more**  **efficient than**  **an induction­run**  **motor that**  **does not**  **incorporate a**  **run**

**capacitor. This**  **constitute a**  **performance­related feature**  **that affects**  **efficiency. Furthermore,** 

**DOE notes**  **that it**  **is not**  **always possible**  **to replace**  **a CSIR**  **motor with**  **a CSCR**  **motor due**  **to the** 

**run capacitor,**  **which is**  **often mounted**  **in an**  **external housing**  **on the**  **motor. In**  **certain**

**applications, the**  **run capacitor**  **mounted on**  **the motor**  **will physically**  **prohibit it**  **from replacing**  **a**

**CSIR motor.**  **This is**  **a design**  **feature that**  **affects utility.**  **For all**  **of these**  **reasons, DOE**  **treats**

**CSIR and**  **CSCR motors**  **as separate**  **equipment classes.** 

**Next, the**  **number of**  **poles in**  **an electric**  **motor determines**  **the synchronous**  **speed (**  i.e.

**, revolutions**  **per minute).**  **There is**  **an inverse**  **relationship between**  **number of**  **poles and**  **speed,**

**meaning that**  **an increase**  **in the**  **number of**  **poles equates**  **to a**  **decrease in**  **the speed**  **of the**  **motor**

**(e.g., going**  **from two**  **to four**  **to six**  **poles, the**  **synchronous speed**  **drops from**  **3,600 to**  **1,800 to** 

**1,200 revolutions**  **per minute).**  **The number**  **of poles**  **has a**  **direct impact**  **on the**  **motor’s**

**performance and**  **efficiency. Consequently,**  **DOE uses**  **the number**  **of poles**  **as a**  **means of** 

**differentiating equipment**  **classes.**

**Finally, in**  **general, efficiency**  **scales with**  **horsepower, or**  **in other**  **words, a**  **3­horsepower**

**motor is**  **usually more**  **efficient than**  **a 1⁄4­horsepower**  **motor. Horsepower**  **is a**  **critical**

**performance attribute**  **of an**  **electric motor,**  **and since**  **there is**  **a correlation**  **with efficiency,**  **DOE**

**uses this**  **as a**  **criterion for**  **distinguishing among**  **equipment classes.** 

**Table 3.2.5**  **presents 24**  **equipment classes**  **(EC) for**  **CSIR motors,**  **broken down**  **by**

**number of**  **poles and**  **horsepower/standard kilowatt**  **equivalent ratings.**  **DOE proposes**  **to have**  **the**

**same table**  **(and EC**  **breakdown) for**  **both CSCR**  **and polyphase**  **motors. Should**  **DOE establish** 

**3­12 minimum**  **energy conservation**  **standards for**  **small electric**  **motors, each**  **“EC” cell**  **in the** 

**following table**  **would be**  **replaced by**  **the applicable**  **nominal full**  **load efficiency**  **value.**

Table 3.2.5. Example of Equipment Classes for Capacitor­Start, Induction­Run Small

Electric Motors

Motor

Horsepower/Standard

Kilowatt Equivalent Six Poles Four Poles Two Poles

**1/4 hp/0.18**  **kW EC**  **#1 EC**  **#2 EC**  **#3**

**1/3 hp/0.25**  **kW EC**  **#4 EC**  **#5 EC**  **#6**

**1/2 hp/0.37**  **kW EC**  **#7 EC**  **#8 EC**  **#9**

**3/4 hp/0.55**  **kW EC**  **#10 EC**  **#11 EC**  **#12**

**1 h**  **p/0.75 kW**  **EC #13**  **EC #14**  **EC #15** 

**11⁄2 hp/1.1**  **kW EC**  **#16 EC**  **#17 EC**  **#18**

**2 h**  **p/1.5 kW**  **EC #19**  **EC #20**  **EC #21** 

**≥ 3**  **hp/2.2 kW**  **EC #22**  **EC #23**  **EC #24** 

**Another important**  **aspect of**  **general­purpose motors**  **covered in**  **this rulemaking**  **is that** 

**each is**  **built in**  **a two­digit**  **frame size,**  **as defined**  **by NEMA**  **MG1–1987. DOE**  **considered, but** 

**then rejected,**  **the idea**  **of differentiating**  **equipment classes**  **by frame**  **size. Frame**  **size is** 

**determined by**  **the shaft**  **height of**  **the motor**  **from the**  **bottom of**  **the base**  **(also called**  **the “D”** 

**dimension) in**  **sixteenths of**  **an inch.**  **For example,**  **a 56­frame**  **motor would**  **have a**  **shaft height**  **of**

**56/16 of**  **an inch,**  **or 3.5**  **inches. DOE**  **is not**  **aware of**  **a direct**  **correlation between**  **efficiency and** 

**frame size**  **that would**  **not generally**  **scale with**  **horsepower. Moreover,**  **frame sizes**  **42, 48,**  **and 56** 

**are manufactured**  **in various**  **horsepower and**  **pole combinations**  **over a**  **range of**  **efficiencies.**

**Therefore, DOE**  **proposes not**  **to differentiate**  **equipment classes**  **by frame**  **size.**

3. 2.3.1 Representative Units

**DOE based**  **its selection**  **of representative**  **units from**  **the 72**  **equipment classes**  **of small** 

**electric motors**  **on three**  **factors: (1)**  **the motors**  **that were**  **studied in**  **the determination**  **analysis,**

**(2) manufacturer’s**  **sales catalogs**  **for this**  **equipment, and**  **(3) the**  **ability to**  **scale from**  **these units** 

**to other**  **units.**

**In the**  **determination analysis,**  **DOE studied**  **five different**  **motors as**  **the representative** 

**units. Two**  **of the**  **motors were**  **capacitor­start, induction­run**  **and three**  **were polyphase.**  **For the** 

**capacitor­start, induction­run**  **motors, DOE**  **chose two**  **similar models**  **with 56**  **and 48**  **frame sizes** 

**to capture**  **different cost­efficiency**  **characteristics associated**  **with those**  **frame sizes.**  **For the** 

**polyphase motors,**  **DOE chose**  **three models,**  **holding frame**  **size constant,**  **but varying**  **the**

**horsepower for**  **two motors.**  **The five**  **motors studied**  **in the**  **determination analysis**  **are presented** 

**in Table**  **3.2.6.**

**3­13**Table 3.2.6. Representative Units Selected for the Determination Analysis

Motor Category Model Horsepower Number of Poles Frame Size

**CSIR Dayton**  **4K856 0.**  **50 4**  **56**

**CSIR Dayton**  **6K965 0.**  **50 4**  **48**

**Polyphase Dayton**  **3N641 0.**  **50 4**  **56**

**Polyphase Dayton**  **2N103 0.**  **50 4**  **56**

**Polyphase Dayton**  **3N102 1.**  **0 4**  **56**

**DOE also**  **reviewed manufacturer**  **catalogs and**  **created a**  **database of**  **over 700**  **motors that** 

**represent all**  **the small**  **electric motors**  **manufactured and**  **listed in**  **the catalogs.**  **Although this** 

**database does**  **not provide**  **information on**  **unit sales,**  **it does**  **provide an**  **indication of**  **the more** 

**popular motors**  **from the**  **standpoint of**  **having a**  **greater variety**  **of certain**  **combinations of** 

**horsepower and**  **frame size.**  **Analyzing this**  **data and**  **shipments data**  **(shown in**  **section 3.2.4)** 

**enabled DOE**  **to select**  **popular configurations**  **of small**  **electric motors.**  **Figure 3.2.1**  **through**

**Figure 3.2.11**  **show shipments**  **data for**  **each motor**  **category broken**  **down by**  **pole configuration** 

**and horsepower,**  **as well**  **as the**  **number of**  **models of**  **each motor**  **category broken**  **down by** 

**horsepower. These**  **figures also**  **show efficiency**  **as a**  **function of**  **horsepower for**  **polyphase and** 

**CSIR motors.** 

Figure 3.2.1. Polyphase Small Electric Motor Shipments Broken Down by Pole

Configuration

**6­pole, 9%**  **2­pole, 23%** 

**4­pole, 68%** 

**3­14**

## Horse ower Figure 3.2.2. Polyphase Small Electric Motor Shipments Broken Down by Horsepower 

## p

**1 1/2**  **HP, 28%** 

**3/4 HP,**  **28% 1/4**  **HP, 2%** 

**1/3 HP,**  **4%**

**1/2HP, 11%** 

**1 HP,**  **19%**

**2­3 HP,**  **7%**

**Figures 3.2.1**  **and 3.2.2**  **are based**  **on historical**  **shipments data**  **submitted by**  **NEMA in** 

**year 2000**  **and projected**  **forward to**  **year 2007.**  **(See section**  **3.2.4 for**  **more detail.)**  **They show** 

**the breakdown**  **of shipments**  **by pole**  **configuration and**  **horsepower. An**  **overwhelming majority** 

**of polyphase**  **motors shipped**  **are four­pole**  **machines and**  **the weighted**  **average horsepower**  **of**

**shipments is**  **1 horsepower.** 

Figure 3.2.3. Models of Polyphase Small Electric Motors Broken Down by Horsepower

**0.25 0.33**  **0.50 0.75**  **1.00 1.50**  **2.00 3.00** 

**Horsepower**

**Th e**  **data in**  **Figure 3.2.3**  **is based**  **on DOE’s**  **database of**  **small electric**  **motors compiled** 

**from several**  **manufacturer’s sales**  **catalogs. This**  **figure shows**  **the distribution**  **of models**  **by**

**horsepower for**  **polyphase motors.**  **The most**  **common horsepower**  **model is**  **3⁄4 horsepower,**  **but**

**the data**  **show a**  **skew toward**  **models around**  **1 horsepower.**  **The data**  **reaffirm the**  **weighted**

**average of**  **1 horsepower**  **for polyphase**  **motor shipments,**  **which is**  **why DOE**  **selected 1** 

**horsepower for**  **the polyphase**  **representative unit.**  **0 10**  **20 30**  **40 50**  **60 70**  **80 N** **u m** **b e** **r o** **f M** **o t** **o r** **s**

**3­15 )**  Figure 3.2.4. Efficiency as Function of Horsepower for Polyphase Small Electric Motors

**50 60**  **70 80**  **90 E** **f f** **i c** **i e** **n c** **y (** **%**

**0.00 0.50**  **1.00 1.50**  **2.00 2.50**  **3.00 3.50** 

**Horsepower**

**Figure 3.2.4**  **shows the**  **relationship between**  **efficiency and**  **horsepower for**  **polyphase**

**motors. As**  **the graph**  **shows, motors**  **with a**  **larger horsepower**  **ratings tend**  **to be**  **more energy** 

**efficient. This**  **substantiates DOE’s**  **decision discussed**  **earlier in**  **this chapter**  **about**

**differentiating equipment**  **classes for**  **small electric**  **motors by**  **horsepower rating.** 

Figure 3.2.5. Capacitor­Start, Induction­Run Small Electric Motor Shipments Broken

Down by Pole Configuration

**2­pole, 32%**  **6­pole, 29%** 

**4­pole, 39%** 

**3­1 6** Figure 3.2.6. Capacitor­Start, Induction­Run Small Electric Motor Shipments Broken

Down by Horsepower

**1/4 HP,**  **18%**

**1/3 HP,**  **30% 3/4**  **HP, 22%**  **1 HP,**  **4% >1**  **HP, 1%** 

**1/2HP, 25%** 

**Figures 3.2.5**  **and 3.2.6**  **are based**  **on historical**  **shipments data**  **submitted by**  **NEMA in** 

**year 2000**  **and projected**  **forward to**  **year 2007.**  **(See section**  **3.2.4 for**  **more detail.)**  **They show** 

**the breakdown**  **of shipments**  **by pole**  **configuration and**  **horsepower. The**  **pole configuration** 

**distribution is**  **fairly even**  **among two,**  **four, and**  **six poles,**  **but four**  **poles are**  **most common.**  **The**

**weighted average**  **horsepower of**  **CSIR motors**  **shipped is**  **1⁄2 hp.** 

Figure 3.2.7. Models of Capacitor­Start, Induction­Run Small Electric Motors Broken

Down by Horsepower

**0.25 0.33**  **0.50 0.75**  **1.00 1.50**  **2.00 3.00** 

**Horsepower**

**Th e**  **data in**  **Figure 3.2.7**  **are based**  **on DOE’s**  **review of**  **manufacturer catalogs**  **and show** 

**the distribution**  **of models**  **by horsepower**  **for CSIR**  **motors. The**  **most common**  **horsepower**

**model is**  **1⁄2 hp**  **and the**  **data trend**  **toward 1⁄2**  **horsepower as**  **an average**  **model. The**  **data reaffirm** 

**the weighted**  **average of**  **1⁄2 horsepower**  **for CSIR**  **shipments, which**  **is why**  **DOE selected**  **1⁄2**

**horsepower for**  **the CSIR**  **representative unit.**  **0 10**  **20 30**  **40 50**  **60 70** **N u** **m b** **e r** **o f** **M o** **t o** **r s** 

**3­17 )**  Figure 3.2.8. Efficiency as a Function of Horsepower for Capacitor­Start, Induction­Run

Small Electric Motors**Efficiency (%**  **90**

**80**

**70**

**60**

**50**

**40**

**0.00 0.50**  **1.00 1.50**  **2.00 2.50**  **3.00 3.50** 

**Horsepower**

**Figure 3.2.8**  **shows the**  **relationship between**  **efficiency and**  **horsepower for**  **CSIR motors.** 

**In general,**  **small electric**  **motors with**  **a larger**  **horsepower ratings**  **are more**  **efficient.**

Figure 3.2.9. Capacitor­Start, Capacitor­Run Small Electric Motor Shipments Broken

Down by Pole Configurations

**2­pole, 32%**  **6­pole, 29%** 

**4­pole, 39%** 

**3­18**Figure 3.2.10. Capacitor­Start, Capacitor­Run Small Electric Motor Shipments Broken

Down by Horsepower

**1/4 HP,**  **18%**

**1/3 HP,**  **30% 3/4**  **HP, 22%**  **1 HP,**  **4% >1**  **HP, 1%** 

**1/2HP, 25%** 

**Figures 3.2.9**  **and 3.2.10**  **are based**  **on historical**  **shipments data**  **submitted by**  **NEMA in** 

**year 2000,**  **projected forward**  **to year**  **2007, and**  **then scaled**  **from CSIR**  **data. (See**  **section 3.2.4** 

**for more**  **detail.) These**  **figures show**  **the breakdown**  **of shipments**  **by pole**  **configuration and** 

**horsepower. The**  **pole configuration**  **distribution is**  **fairly even**  **between two,**  **four, and**  **six poles,** 

**but four**  **poles are**  **most common.**  **The weighted**  **average horsepower**  **of CSCR**  **motors shipped**  **is**

**1⁄2 horsepower.** 

Figure 3.2.11. Models of Capacitor­Start, Capacitor­Run Small Electric Motors Broken

Down by Horsepower

**0.25 0.33**  **0.50 0.75**  **1.00 1.50**  **2.00 3.00** 

**Horsepower**

**The weighted**  **average horsepower**  **of CSCR**  **motors shipped**  **was 1⁄2**  **horsepower, but**  **the**

**most common**  **horsepower model**  **was clearly**  **3⁄4 horsepower,**  **shown in**  **Figure 3.2.11.**  **Since**

**DOE created**  **a 1⁄2­horsepower**  **model for**  **CSIR, it**  **chose 3⁄4**  **horsepower for**  **CSCR.**

**DOE did**  **not show**  **efficiency as**  **a function**  **of horsepower**  **for these**  **motors because**  **there**

**were fewer**  **CSCR models**  **in manufacturer**  **catalogs and**  **only a**  **few of**  **those manufacturers** 

**reported efficiency.**  **0 2**  **4 6**  **8 10**  **12 14**  **16 N** **u m** **b e** **r o** **f M** **o t** **o r** **s**

**3­19 DOE**  **also considered**  **the ability**  **to scale**  **from the**  **findings on**  **the representative**  **unit from** 

**the representative**  **equipment class**  **to the**  **adjoining equipment**  **classes, varying**  **both number**  **of**

**poles and**  **horsepower ratings.**  **DOE selected**  **at least**  **one motor**  **in each**  **of the**  **three categories**  **of**

**small electric**  **motors (i.e.,**  **polyphase, CSIR**  **and CSCR).** 

**Table 3.2.7**  **presents the**  **four representative**  **units DOE**  **selected for**  **this draft**  **analysis.**

**The motors**  **are four­pole**  **motors and,**  **in view**  **of DOE’s**  **analysis of**  **manufacturer catalogs,**  **this is** 

**the most**  **common configuration**  **for these**  **horsepower ratings.**  **As in**  **the determination**  **analysis,**

**DOE selected**  **two CSIR**  **motors with**  **the same**  **horsepower rating**  **and number**  **of poles,**  **but**

**different frame**  **sizes, to**  **capture any**  **differences in**  **the cost­efficiency**  **relationship among**  **frame**

**sizes. DOE**  **also selected**  **motors that**  **approximate the**  **middle of**  **the range**  **of covered** 

**horsepowers, partly**  **to minimize**  **any error**  **that might**  **be introduced**  **as the**  **efficiency of**  **these**

**motors are**  **extrapolated to**  **other horsepower**  **ratings.**

Table 3.2.7. Representative Units Selected for the Preliminary Notice of Proposed

Rulemaking

Motor Category Horsepower Number of Poles Frame Size

Polyphase **1.00 4**  **56**

CSIR **0.50 4**  **56 m** 

CSIR **0.50 4**  **48**

CSCR **0.75 4**  **56**

**DOE identified**  **these four**  **as representative**  **units of**  **interest. All**  **four units**  **fit the** 

**requirements of**  **a NEMA**  **general­purpose, single**  **speed, induction**  **motor, rated**  **for continuous** 

**duty, and**  **built with**  **open construction**  **in a**  **two­digit frame**  **size. In**  **the engineering**  **analysis**

**(chapter 5),**  **DOE provides**  **additional detail**  **on each**  **motor, including**  **input voltage,**  **baseline**

**efficiency, and**  **other critical**  **performance characteristics.** 

3.2.3.2 Scaling Findings from Representative Units

**DOE believes**  **that it**  **is unrealistic**  **to conduct**  **an analysis**  **of representative**  **units from**  **all**

**72 equipment**  **classes for**  **small electric**  **motors. Therefore,**  **DOE is**  **selecting a**  **small sample**  **of**

**motors from**  **popular equipment**  **classes that**  **are approximately**  **in the**  **middle of**  **the range**  **of**

**covered product**  **(both in**  **terms of**  **number of**  **poles and**  **horsepower rating).**  **DOE will**  **then**

**extrapolate its**  **findings from**  **each of**  **the three**  **motor categories**  **to other**  **covered small**  **electric**

**motor equipment**  **classes that**  **were not**  **analyzed, as**  **shown in**  **Table 3.2.8.** 

**m DOE**  **identified these**  **four motors**  **as the**  **representative units**  **to study,**  **and then**  **conducted an**  **engineering analysis** 

**to study**  **the relationship**  **between motor**  **efficiency and**  **manufacturer selling**  **price. DOE**  **found that**  **there was** 

**virtually no**  **difference between**  **the 48**  **and 56**  **frame sizes**  **for the**  **1⁄2­horsepower, four­pole**  **CSIR motors.**  **Therefore,**

**DOE elected**  **to drop**  **the 56**  **frame size**  **from its**  **analysis, since**  **frame size**  **tends to**  **scale with**  **horsepower, and**  **at this** 

**rating it**  **would be**  **more common**  **to find**  **a 48**  **frame than**  **a 56.**  **This issue**  **is discussed**  **in some**  **detail in**  **the**

**engineering analysis**  **(chapter 5)**  **and the**  **appendix to**  **the engineering**  **chapter (appendix**  **5A).**

**3­20**Table 3.2.8. Scaling from Representative Motors to all Equipment Classes

Horsepower 6 poles 4 poles 2 poles

**1⁄4 hp**  **EC #1**  **EC #2**  **EC #3** 

**1/3 hp**  **EC #4**  **EC #5**  **EC #6** 

**1⁄2 hp**  **EC #7**  **EC #8**  **EC #9** 

**3⁄4 hp**  **EC #10**  **EC #11**  **EC #12** 

**1 hp**  **EC #13**  **EC #14**  **EC #15** 

**1 1⁄2**  **hp EC**  **#16 EC**  **#17 EC**  **#18**

**2 hp**  **EC #19**  **EC #20**  **EC #21** 

**> 3**  **hp EC**  **#22 EC**  **#23 EC**  **#24**

**DOE addresses**  **the details**  **of the**  **scaling relationships,**  **including the**  **basis for**  **how these** 

**were derived,**  **in preliminary**  **TSD chapter**  **5.**

3.2.4 Shipments

**To estimate**  **national energy**  **savings from**  **this proposed**  **regulation, DOE**  **will estimate** 

**disaggregated shipments**  **of small**  **electric motors,**  **broken down**  **by equipment**  **class. Individual** 

**manufacturers consider**  **such information**  **to be**  **highly sensitive,**  **which in**  **turn complicates**  **data**

**collection. NEMA,**  **as the**  **manufacturers’ trade**  **association, offered**  **to coordinate**  **and aggregate** 

**its members’**  **shipments data.**  **Working through**  **NEMA, DOE**  **prepared a**  **shipments**

**questionnaire based**  **on the**  **previous data**  **collection tool**  **that was**  **circulated in**  **2002 for**  **the**

**determination analysis.**  **In turn,**  **NEMA would**  **receive current**  **shipments data**  **from its**  **members,**

**aggregate that**  **data, screen**  **out any**  **equipment classes**  **with too**  **few manufacturers**  **reporting, and** 

**provide the**  **combined shipments**  **tables to**  **DOE.**

**Ho wever,**  **there was**  **limited participation**  **from NEMA’s**  **members and**  **consequently DOE** 

**decided to**  **take a**  **new approach.**  **Essentially, DOE**  **chose to**  **use the**  **earlier small**  **electric motors** 

**shipments data**  **it had**  **received from**  **NEMA during**  **the determination**  **analysis, and**  **apply a** 

**growth estimate**  **based on**  **the observed**  **market trends**  **for those**  **motors. n**  **Then DOE**  **took the** 

**small electric**  **motors shipments**  **estimate that**  **NEMA had**  **provided for**  **2000 and**  **extrapolated**

**those data**  **to estimate**  **shipments in**  **2007, based**  **on the**  **observed market**  **growth trends**  **for small** 

**electric motors**  **between 1990**  **and 1999.**  **(Trend information**  **was extrapolated**  **from U.S.**  **Census**

**Bureau data.)** 

**In particular,**  **NEMA provided**  **shipment data**  **to DOE**  **on general**  **purpose, AC,**  **polyphase,**

**single­speed, induction**  **motors built**  **in a**  **two­digit frame**  **number series**  **with open**  **construction**

**and rated**  **for continuous**  **duty in**  **accordance with**  **MG1–1987. Table**  **3.2.9 presents**  **the**

**disaggregated shipments**  **estimates from**  **NEMA.**

**n The**  **Determination Analysis**  **was published**  **on July**  **10, 2006.**  **“Energy Conservation**  **Program for**  **Certain**

**Industrial Equipment:**  **Determination Concerning**  **the Potential**  **for Energy**  **Conservation Standards**  **for Small** 

**Electric Motors.”**  **71 FR**  **38799.**

**3­21**Table 3.2.9. National Electrical Manufacturers Association Polyphase Small Electric Motor

Shipment Data, 2000

Horsepower Six Poles Four Poles Two Poles Total

**1/4 hp**  ***** ***** ***** **9,163**

**1/3 hp**  **3,788 12,899**  **2,585 19,272** 

**1/2 hp**  **6,478 39,501**  **2,856 48,835** 

**3/4 hp**  **9,729 47,084**  **65,405 122,218** 

**1 hp**  ***** **56,783** ***** **84,670**

**1 1/2**  **hp** ***** **115,638** ***** **124,959**

**2­3 hp** 

**­ 22,384**  **10,149 32,533** 

**441,650**

***** **Dat a**  **withheld by**  **NEMA due**  **to insufficient**  **number of**  **manufacturers reporting**  **for those**  **ratings/poles.**

**Using NEMA’s**  **shipment estimates**  **for open**  **drip­proof, polyphase**  **small electric**  **motors,**

**DOE applied**  **the same**  **average market**  **growth rate**  **observed in**  **the 1990**  **through 1999**  **shipment**

**data. DOE**  **found that**  **the average**  **annual growth**  **rate was**  **3.4 percent**  **for open**  **drip­proof**

**polyphase small**  **electric motors.**  **DOE then**  **applied the**  **3.4 percent**  **average annual**  **growth rate**  **to**

**the year**  **2000 estimate**  **that NEMA**  **had provided,**  **and extrapolated**  **it to**  **2007. Due**  **to an** 

**insufficient number**  **of manufacturers**  **reporting NEMA**  **was unable**  **to provide**  **shipments data**  **for**

**all the**  **small electric**  **motors in**  **2000. Therefore,**  **DOE apportioned**  **the unallocated**  **shipments**

**from the**  **total column**  **among the**  **number of**  **poles. Where**  **no shipment**  **breakdown by**  **poles was** 

**provided, such**  **as for**  **the one­quarter**  **horsepower polyphase**  **motors, DOE**  **used the**  **same**

**proportional breakdown**  **as the**  **closest rating**  **(i.e., the**  **one­third horsepower)**  **and established**  **an**

**even, average**  **breakdown between**  **the two**  **and six**  **pole motors.** 

Table 3.2.10. Estimated Polyphase Small Electric Motor National Shipments, 2007

Horsepower Six Poles Four Poles Two Poles Total

**1/4 hp**  **1,967 7,637**  **1,967 11,571** 

**1/3 hp**  **4,784 16,289**  **3,264 24,338** 

**1/2 hp**  **8,181 49,884**  **3,607 61,671** 

**3/4 hp**  **12,286 59,460**  **82,596 154,342** 

**1 hp**  **17,608 71,708**  **17,608 106,925** 

**1 1/2**  **hp 5,885**  **146,033 5,885**  **157,804**

**2­3 hp** 

**­ 28,268**  **12,817 41,084** 

**50,712 379,278**  **127,745 557,735** 

**NEMA provided**  **shipments data**  **to DOE**  **on general**  **purpose, AC,**  **CSIR, single­speed** 

**induction motors**  **built in**  **a two­digit**  **frame number**  **series with**  **open construction**  **and rated**  **for**

**continuous duty.**  **Table 3.2.11**  **presents the**  **disaggregated shipments**  **estimate from**  **NEMA.**

**3­2 2** Table 3.2.11. National Electrical Manufacturers Association Capacitor­Start, InductionRun Small Electric Motor Shipment Data, 2000

Horsepower Six Poles Four Poles Two Poles Total

**1/4 hp**  ***** **342,064** ***** **882,878**

**1/3 hp**  **551,566 609,264**  **354,258 1,515,088** 

**1/2 hp**  **301,198 493,151**  **465,799 1,260,148** 

**3/4 hp**  ***** **385,013** ***** **1,121,644**

**1 hp** 

**­ 53,042**  **143,571 196,613** 

**>1 hp** 

**­ 23,638**  **24,892 48,530** 

**TOTAL 5,024,901** 

***** **Dat a**  **withheld by**  **NEMA due**  **to insufficient**  **number of**  **manufacturers reporting**  **for those**  **ratings/poles.**

**Using NEMA’s**  **shipments estimates**  **for open**  **drip­proof, CSIR**  **small electric**  **motors,**

**DOE applied**  **the same**  **average market**  **growth rate**  **observed in**  **the 1990**  **through 1999**  **Census**

**Bureau shipment**  **data. DOE**  **found that**  **the average**  **annual growth**  **rate was**  **1.1 percent**  **for open** 

**drip­proof CSIR**  **small electric**  **motors. DOE**  **then applied**  **the 1.1**  **percent average**  **annual growth** 

**rate to**  **the year**  **2000 estimate**  **that NEMA**  **provided, and**  **extrapolated it**  **to 2007.**  **Due to**  **an**

**insufficient number**  **of manufacturers**  **reporting, NEMA**  **was unable**  **to provide**  **shipments data**  **for**

**all the**  **small electric**  **motors in**  **2000. Therefore,**  **DOE apportioned**  **the unallocated**  **shipments**

**data, from**  **the total**  **column, in**  **a manner**  **that is**  **proportional to**  **the next**  **closest horsepower** 

**rating.**

Table 3.2.12. Estimated Capacitor­Start, Induction­Run Small Electric Motor National

Shipments, 2007

Horsepower Six Poles Four Poles Two Poles Total

**1/4 hp**  **348,160 384,581**  **223,615 956,357** 

**1/3 hp**  **597,471 659,971**  **383,742 1,641,183** 

**1/2 hp**  **326,266 534,194**  **504,566 1,365,025** 

**3/4 hp**  **290,405 475,480**  **449,108 1,214,994** 

**1 hp** 

**­ 57,456**  **155,520 212,976** 

**>1 hp** 

**­ 25,605**  **26,964 52,569** 

**TOTAL 1,562,302**  **2,137,288 1,743,514**  **5,443,104**

**Fin ally,**  **NEMA was**  **unable to**  **provide shipments**  **data for**  **CSCR motors,**  **due to**  **an**

**insufficient number**  **of manufacturers**  **reporting. However,**  **in its**  **determination analysis,**  **DOE**

**estimated that**  **CSCR motor**  **shipments represent**  **approximately 5**  **percent of**  **the shipments**  **of**

**capacitor­start motors.**  **Therefore, DOE**  **estimated shipments**  **of CSCR**  **motors in**  **2007 by**  **scaling**

**the projected**  **CSIR units**  **sold in**  **2007 to**  **CSCR, based**  **on a**  **19 to**  **1 ratio.** 

**3­2 3** Table 3.2.13. Estimated Capacitor­Start, Capacitor­Run Small Electric Motor National

Shipments, 2007

Horsepower Six Poles Four Poles Two Poles Total

**1/4 hp**  **18,324 20,241**  **11,769 50,335** 

**1/3 hp**  **31,446 34,735**  **20,197 86,378** 

**1/2 hp**  **17,172 28,115**  **26,556 71,843** 

**3/4 hp**  **15,284 25,025**  **23,637 63,947** 

**1 hp** 

**­ 3,024**  **8,185 11,209** 

**>1 hp** 

**­ 1,348**  **1,419 2,767** 

**TOTAL 82,226**  **112,489 91,764**  **286,479**

3.2.5 Manufacturers and Market Share

**Four large**  **manufacturers dominate**  **the small**  **electric motor**  **market for**  **this rulemaking:** 

• **A.O. Smith**  **Electrical Products**  **Company;**

• **Baldor Electric**  **Company;**

• **Emerson Motor**  **Technologies; and** 

• **Regal­Beloit Corporation.** 

**Th e**  **four manufacturers**  **identified above**  **are all**  **major manufacturers**  **with diverse** 

**portfolios of**  **product offerings,**  **including small**  **electric motors**  **covered under**  **EPCA. Over**  **the**

**past decade,**  **there has**  **been a**  **consolidation of**  **motor manufacturing**  **in the**  **United States**  **and, in** 

**part, the**  **limited number**  **of small**  **electric motor**  **manufacturers is**  **a result**  **of mergers**  **and**

**acquisitions occurring**  **over the**  **last few**  **decades.**

**DOE does**  **not have**  **empirical data**  **on the**  **market shares**  **of particular**  **manufacturers of** 

**small electric**  **motors. Nevertheless,**  **estimates of**  **available cumulative**  **data indicate**  **that**

**shipments of**  **small electric**  **motors from**  **these four**  **companies constitute**  **over 90**  **percent of**  **the**

**total U.S.**  **market. Thus,**  **DOE believes**  **that the**  **cumulative shipment**  **estimates provided**  **by**

**NEMA for**  **the determination**  **analysis constitute**  **a good**  **estimate of**  **overall national**  **shipments.**

3.2.5.1 Small Businesses

**Although the**  **small electric**  **motor market**  **is predominantly**  **supplied by**  **large**

**manufacturers, DOE**  **will examine**  **those small**  **businesses that**  **manufacture small**  **electric motors** 

**during the**  **NOPR stage**  **of the**  **rulemaking. In**  **general, the**  **Small Business**  **Administration (SBA)** 

**defines a**  **small business**  **manufacturing enterprise**  **for “motor**  **and generator**  **manufacturing” as** 

**one that**  **has 1,000**  **or fewer**  **employees. The**  **number of**  **employees in**  **a small**  **business is**  **rolled**

**up with**  **the total**  **employees of**  **the parent**  **company; it**  **does not**  **represent the**  **division**

**manufacturing small**  **electric motors.**  **SBA lists**  **small business**  **size standards**  **for industries**  **as**

**they are**  **described in**  **the North**  **American Industry**  **Classification System**  **(NAICS). For**  **small**

**electric motors,**  **the size**  **standard is**  **matched to**  **NAICS code**  **335312, Motor**  **and Generator** 

**1 Manufacturing.** 

**3­2 4** 3.2.6 Application and Performance of Existing Equipment

**The general**  **purpose CSIR,**  **CSCR and**  **polyphase small**  **electric motors**  **covered are**  **used**

**in a**  **fairly wide**  **range of**  **applications, including**  **the following:** 

• **blowers**

• **business equipment** 

• **commercial food**  **processing**

• **compressors**

• **conveyors**

• **fans**

• **farm equipment** 

• **general industrial**  **applications**

• **heating, ventilation,**  **and air­conditioning**  **equipment**

• **machine tools** 

• **milking machines** 

• **pumps**

• **woodworking machines** 

3.2.7 Trade Associations

**DOE is**  **aware of**  **two trade**  **associations for**  **manufacturers of**  **small electric**  **motors: the** 

**National Electrical**  **Manufacturers Association**  **(NEMA) and**  **the Motors**  **and Motion**  **Association**

**(SMMA). o**  **All four**  **major manufacturers**  **discussed above**  **are members**  **of NEMA**  **and SMMA.** 

3.2.7.1 National Electrical Manufacturers Association

**NEMA was**  **established as**  **a trade**  **association in**  **1926, and**  **has since**  **been divided**  **into**

**four groups**  **that provide**  **different functions**  **for its**  **members:**

• **NEMA/TEC, Technical**  **Services Department** 

• **NEMA/GOV, Government**  **Relations Department** 

• **NEMA/PAC, Political**  **Action Committee** 

• **NEMA/BIS, Business**  **Information Services** 

**Th rough**  **these groups,**  **NEMA helps**  **to standardize**  **the performance,**  **size, and** 

**functionality of**  **electrical equipment**  **for its**  **members. An**  **example of**  **NEMA’s role**  **in**

**standardization is**  **the NEMA**  **Standard MG1**  **document, p**  **which is**  **a reference**  **document for** 

**motor and**  **generator manufacturers**  **and users.**  **NEMA Standard**  **MG1 provides**  **guidance to** 

**motor manufacturers**  **on performance**  **and construction**  **specifications for**  **a broad**  **range of**  **electric**

**motors. By**  **standardizing around**  **certain parameters,**  **NEMA makes**  **it easier**  **for users**  **to identify** 

**o For**  **more information**  **about The**  **Motors and**  **Motion Association,**  **visit www.smma.org** 

**. Li**  **kewise, for**  **information**

**about NEMA,**  **visit www.nema.org.** 

**p NEMA’s**  **MG 1**  **document can**  **be purchased**  **online at**  **www.nema.org/st ds/MG**  **1.cfm**

**.**

**3­25 and**  **purchase electric**  **motors. NEMA**  **Standard MG1**  **is a**  **complete industry**  **reference document** 

**2 for**  **standardizing the**  **motors offered**  **in the**  **market.**

**In addition**  **to MG**  **1, NEMA**  **established and**  **promoted a**  **high efficiency**  **standard for** 

**electric motors**  **through the**  **“NEMA Premium®”**  **label for**  **qualifying motors.**  **q NEMA**  **motor**

**manufacturers attach**  **this label**  **to motors**  **that are**  **built to**  **prescribed high**  **efficiency standards.** 

**These standards**  **exceed the**  **minimum requirements**  **established by**  **EPACT 92,**  **which requires** 

**general­purpose motors**  **from 1**  **to 200**  **horsepower to**  **meet certain**  **minimum efficiency**  **levels.**

**See section**  **3.2.9 for**  **more discussion**  **on these**  **minimum efficiency**  **levels.**

3.2.7.2 The Motors and Motion Association

**SMMA is**  **a trade**  **association focused**  **on electric**  **motors and**  **motion control**  **products.**

**SMMA has**  **over 120**  **members, including**  **manufacturers, suppliers,**  **users, consultants,** 

**universities, and**  **distributors. SMMA**  **supports its**  **members through**  **programs and**  **services,**

**including annual**  **conferences, in­house**  **educational courses**  **from the**  **SMMA Motor**  **and Motion** 

**College, the**  **publication of**  **industry market**  **trend data,**  **and small**  **electric motor**  **research activity.**  **r**

**In 1995,**  **SMMA founded**  **the Electric**  **Motor Education**  **and Research**  **Foundation**

**(EMERF), whose**  **mission is**  **“to advance**  **and promote**  **the electric**  **motor industry**  **through**

**education, pre­competition**  **research, and**  **facilitation of**  **technology transfer**  **within the**  **industry**

**3 and**  **in cooperation**  **with academic,**  **private research**  **and governmental**  **organizations.” EMERF**

**is important**  **because it**  **is a**  **segment of**  **the SMMA**  **that promotes**  **energy efficiency**  **through**

**teaching and**  **providing information**  **on new**  **motor technologies.** 

3.2.8 Regulatory Programs

**Under EPCA,**  **as amended**  **by EPACT**  **1992, each**  **general­purpose three­phase**  **induction**

**motor, which**  **is covered**  **by definition**  **and manufactured**  **for distribution**  **in commerce**  **in the** 

**United States,**  **is required**  **to have**  **a nominal**  **full load**  **efficiency that**  **is not**  **less than**  **the efficiency** 

**in 10**  **CFR 431.25.**  **The output**  **ratings of**  **these electric**  **motors are**  **from 1**  **to 200**  **horsepower and,** 

**as such,**  **there appears**  **to be**  **some overlap**  **with the**  **1 to**  **3 horsepower**  **small electric**  **motors**

**covered in**  **this rulemaking.**  **However, the**  **electric motors**  **covered under**  **the EPACT**  **1992**

**amendment are**  **defined as**  **“T­frame” and**  **constructed according**  **to NEMA**  **standard three­digit** 

**frame series**  **dimensions for**  **mounting and**  **interchangeability. The**  **small electric**  **motors covered** 

**in the**  **analysis are,**  **by definition,**  **built in**  **a “two­digit**  **frame number**  **series” for**  **which the** 

**dimensions for**  **mounting and**  **interchangeability are**  **fundamentally different**  **from “T­frame”** 

**motors. This**  **one element**  **in the**  **definition of**  **“small electric**  **motor,” distinctly**  **separates the** 

**identity of**  **“small electric**  **motors” from**  **“electric motors”**  **covered by**  **EPCA. Therefore,**  **DOE**

**concludes that**  **there is**  **no overlap**  **between these**  **covered electric**  **motors.**

**q ®** 

**NEMA’s Premium Motors**  **program can**  **be reviewed**  **at www.nema.org/**  **gov/energy/efficiency/premium**

**.**

**r Information**  **about the**  **SMMA Motor**  **and Motion**  **College can**  **be obtained**  **at**

**www.smma.org/mot or.college.schedule.html** 

**.**

**3­26 In**  **general, EPCA,**  **as amended**  **by EISA**  **2007, covers**  **certain categories**  **of motors**  **other**

**than those**  **already covered**  **under the**  **EPACT 1992**  **amendment and**  **for some,**  **it extends**  **the**

**upper limit**  **of the**  **output power**  **range from**  **201 horsepower**  **to 500**  **horsepower. For**  **all of**  **these**

**motors, EISA**  **2007 prescribes**  **nominal full**  **load efficiency**  **levels as**  **defined in**  **NEMA MG**  **1–**

**2006, Table**  **12–11. Further,**  **for those**  **electric motors**  **already covered**  **under the**  **EPACT 1992** 

**amendment, EISA**  **2007 prescribes**  **nominal full**  **load efficiency**  **levels as**  **defined in**  **NEMA MG** 

**1–2006, Table**  **12–12. EISA**  **2007 does**  **not however,**  **address efficiency**  **levels for**  **small electric** 

**motors that**  **are the**  **subject of**  **this analysis.** 

**Nev ertheless,**  **EPACT 1992**  **amended EPCA**  **to cover**  **“small electric**  **motors” and**  **directed**

**the Secretary**  **of Energy**  **to make**  **a determination**  **as to**  **whether energy**  **conservation standards**  **for**

**covered small**  **electric motors**  **would be**  **technologically feasible,**  **economically justified,**  **and**

**would result**  **in significant**  **energy savings.**  **42 U.S.C.**  **6317(b). Based**  **on its**  **analysis of**  **available**

**information, DOE**  **determined that**  **energy conservation**  **standards for**  **the defined**  **small electric** 

**motors appear**  **to meet**  **these criteria.**  **71 FR**  **38807. As**  **a result,**  **DOE has**  **undertaken a** 

**rulemaking process**  **for small**  **electric motors**  **as directed**  **by EPCA.** 

3.2.9 Non­Regulatory Programs

**DOE reviewed**  **voluntary programs**  **that promote**  **energy efficient**  **electric motors**  **in the** 

**United States,**  **including the**  **DOE Motor**  **Challenge program,**  **NEMA Premium**  **energy efficient** 

**motors program,**  **and Consortium**  **for Energy**  **Efficiency (CEE)**  **Premium Efficiency**  **motors**

**program..**

3.2.9.1 Department of Energy Motor Challenge Program

**In general,**  **motor­driven equipment**  **accounts for**  **more than**  **70 percent**  **of all**  **electricity**

**consumption by**  **U.S. industries.**  **In 1993,**  **DOE launched**  **its industry/government**  **partnership,**

**Motor Challenge**  **Program with**  **the goals**  **of increasing**  **the energy­efficiency**  **of electric**  **motor**

**driven systems**  **in domestic**  **industry and**  **enhancing environmental**  **quality. The**  **program uses**  **a**

**market­driven approach**  **to promote**  **the design,**  **purchase, installation,**  **and management**  **of**

**energy­efficient electric**  **motors and**  **motor­driven systems**  **and equipment,**  **such as**  **pumps, fans,** 

**and compressors.**  **It was**  **designed to**  **help industry**  **capture 5**  **billion kilowatt­hours**  **per year**  **of**

**electricity savings**  **and 1.2**  **million metric**  **tons of**  **carbon equivalent**  **by the**  **year 2000,**  **with**

**projections of**  **much larger**  **and longer­term**  **national energy**  **savings opportunities**  **of over**  **100**

**billion kilowatt­hours**  **per year**  **by the**  **year 2010.**  **s**

**The Motor**  **Challenge program**  **encompasses three­phase**  **60 Hertz**  **motors rated**  **1**

**horsepower and**  **above. Its**  **elements and**  **offerings include:**  **the DOE**  **Energy Efficiency**  **and**

**Renewable Energy**  **(EERE) Information**  **Center, which**  **provides up­to­date**  **information about**  **the**

**practicality and**  **profitability of**  **electric motor**  **system strategies;**  **design decision**  **tools, such**  **as**

**MotorMaster+ software;**  **Showcase Demonstration**  **projects; training;**  **workshops; and** 

**conferences. In**  **general, the**  **response to**  **the program**  **from industry**  **has been**  **overwhelmingly**

**s For**  **more information**  **about DOE**  **“BestPractices,” under**  **the DOE**  **Industrial Technologies**  **Program, and**  **Motor**

**Challenge, visit**  **http://www1.eere.energy.gov/industry/bestpractices/index.html.**

**3­27 favorable.**  **The Motor**  **Challenge program**  **is no**  **longer active;**  **however, the**  **EERE Information** 

**Center and**  **the MotorMaster+**  **database of**  **industrial motors**  **remain viable.** 

**Th e**  **EERE Information**  **Center answers**  **questions on**  **energy efficient**  **products and** 

**services and**  **refers callers**  **to the**  **most appropriate**  **DOE/EERE resources.**  **Industrial callers**  **are**

**eligible for**  **an advanced**  **level of**  **service that**  **includes engineering**  **assistance, research,**  **and**

**software support**  **for plant**  **staff and**  **industrial service**  **providers working**  **on industrial**  **energy**

**savings projects.**  **t**

**MotorMaster+ is**  **an energy­efficient**  **motor selection**  **and management**  **tool, which** 

**includes a**  **database of**  **over 20,000**  **electric motors.**  **It features**  **motor inventory**  **management**

**tools, maintenance**  **log tracking,**  **efficiency analysis,**  **savings evaluation,**  **energy accounting,**  **and**

**environmental reporting**  **capabilities. u**  **Recently, MotorMaster+**  **has been**  **expanded to**  **include an** 

**International Electrotechnical**  **Commission 50**  **Hertz database**  **that contains**  **0.03, 0.04,**  **0.06, 0.09,** 

**0.12, 0.15,**  **0.18, 0.25,**  **0.3, 0.37,**  **0.45,0.55, and**  **0.75 kW**  **motors–the equivalent**  **of polyphase** 

**small electric**  **motors but**  **rated in**  **kilowatts. Many**  **manufacturers have**  **supplied data**  **to**

**MotorMaster+ that**  **was outside**  **the scope**  **of small**  **electric motors,**  **nevertheless, the**  **database**

**could be**  **expanded in**  **the future**  **to include**  **small electric**  **motors.**

3.2.9.2 National Electrical Manufacturers Association Premium Efficiency Motor

Program

**On January**  **11, 1989,**  **NEMA established**  **voluntary energy**  **efficiency levels**  **for 1**  **through**

**200 horsepower,**  **polyphase squirrel­cage**  **induction motors.**  **For an**  **electric motor**  **to be**  **classified**

**as “energy**  **efficient,” it**  **was required**  **to meet**  **certain levels**  **of efficiency**  **in NEMA**  **Standards**

**Publication MG**  **1–1987 (Revised**  **March 1991).**  **In 1992,**  **the NEMA**  **efficiency levels**  **were**

**incorporated into**  **section 342(b)**  **of EPACT**  **1992 and**  **subsequently codified**  **in 10**  **CFR 431.25.** 

**In 2001,**  **the NEMA**  **Premium Efficiency**  **Motor Program**  **was established**  **to provide**  **special**

**recognition to**  **electric motors**  **that exceed**  **the required**  **efficiency levels**  **established by**  **EPACT**

**1992. NEMA**  **Premium labeled**  **motors help**  **purchasers identify**  **more efficient**  **motors and** 

**4 v optimize**  **motor system**  **efficiency commensurate**  **with a**  **particular application.** 

**Go ing**  **a step**  **beyond EPACT,**  **NEMA Premium**  **applies to**  **single­speed, polyphase;**  **1 to** 

**500 horsepower;**  **2­, 4­,**  **and 6­pole;**  **squirrel­cage; induction**  **motors; NEMA**  **Designs A**  **or B;**  **600**

**5 volts**  **or less;**  **and rated**  **for continuous**  **duty operation.**  **Such electric**  **motors are**  **typically used**  **in**

**industrial applications**  **operating more**  **than 2000**  **hours per**  **year. The**  **NEMA Premium** 

**Efficiency Motor**  **Program does**  **not cover**  **small electric**  **motors as**  **they are**  **defined in**  **EPCA.**

**Nevertheless, some**  **motor manufacturers**  **offer polyphase,**  **capacitor­start induction­run,**  **and**

**capacitor­start capacitor­run**  **small electric**  **motors at**  **premium efficiency**  **levels.**

**t For**  **more information**  **about the**  **EERE Information**  **Center, visit** 

**http://www1.eere.energy.gov/industry/bestpractices/info_center.html.**

**u For**  **more information**  **about MotorMaster+,**  **visit www1.eere.energy.gov/**  **industry/bestpractices/software.html#mm**

**.**

**For more**  **information about**  **the NEMA**  **Premium Efficiency**  **Motor Program,**  **visit**

**http://www.nema.org/gov/energy/efficiency/premium/.**

**3­28 v** 3.2.9.3 Consortium for Energy Efficiency

**The Consortium**  **for Energy**  **Efficiency (CEE)**  **is a**  **nonprofit corporation**  **that develops** 

**initiatives for**  **its North**  **American members**  **to promote**  **the manufacture**  **and purchase**  **of energy** 

**efficient products,**  **including electric**  **motors and**  **services. Its**  **members include**  **utilities,**

**statewide and**  **regional market**  **transformation administrators,**  **environmental groups,**  **research**

**organizations and**  **state energy**  **offices in**  **the U.S.**  **and Canada.**  **Also included**  **in the**  **CEE**

**collaborative process**  **are manufacturers,**  **retailers, and**  **government agencies.** 

**In 1996,**  **CEE began**  **its Premium­Efficiency**  **Motors Initiative**  **to promote**  **the production,** 

**distribution, and**  **adoption of**  **premium efficiency**  **motors over**  **motors meeting**  **the minimum** 

**efficiency levels**  **established under**  **EPACT 1992**  **In 1999,**  **CEE took**  **a systems**  **approach to** 

**energy savings**  **and launched**  **its Motor**  **Systems Initiative**  **that viewed**  **the motor**  **as a**  **component**

**of a**  **larger system,**  **where efficient**  **motors, adjustable**  **speed drives,**  **and system­specific**  **design**

**strategies would**  **provide the**  **greatest opportunity**  **for savings.**  **Then, in**  **2001, CEE**  **launched its** 

**Motor Decisions**  **Matter to**  **promote greater**  **awareness of**  **the benefits**  **of motor**  **systems**

**efficiency. In**  **June 2001,**  **CEE and**  **NEMA aligned**  **to promote**  **NEMA Premium**  **motor efficiency** 

**6 levels**  **that are**  **higher than**  **EPACT 1992**  **requirements.**

**In May**  **2007, CEE**  **published the**  **Energy­Efficiency Incentive**  **Programs**

**– Premium** 

**Efficiency Motors**  **& Adjustable**  **Speed Drives**  **in the**  **U.S and**  **Canada, which**  **provides**

**information about**  **the incentive­based**  **programs in**  **North America.**  **These programs**  **concentrate**

**on 1**  **to 200**  **horsepower motors,**  **but some**  **include 201**  **to 500**  **horsepower motors.**  **DOE reviewed** 

**the report**  **and the**  **CEE program**  **descriptions it**  **contains, but**  **did not**  **find any**  **incentives that** 

**explicitly cover**  **small electric**  **motors. It**  **appears that**  **the programs**  **cover commercial**  **and**

**industrial motors**  **rated from**  **1 to**  **500 horsepower,**  **although there**  **is some**  **potential for**  **crossover**

**to small**  **polyphase electric**  **motors in**  **the 1**  **to 3**  **horsepower range.**  **w There**  **are a**  **number of** 

**different programs**  **broken down**  **by region.**  **For more**  **information on**  **these programs,**  **download**

**7 the**  **report from**  **CEE.**

3.3 TECHNOLOGY ASSESSMENT

**The small**  **electric motors**  **covered in**  **this rulemaking**  **are all**  **AC induction**  **motors.**

**Induction motors**  **have two**  **core components:**  **a stator**  **and a**  **rotor. The**  **components work** 

**together to**  **convert electrical**  **energy into**  **rotational mechanical**  **energy. This**  **is done**  **by creating** 

**a rotating**  **magnetic field**  **in the**  **stator, which**  **induces a**  **current flow**  **in the**  **rotor. This**  **current**

**flow creates**  **an opposing**  **magnetic field**  **in the**  **rotor, which**  **creates rotational**  **forces. Because**  **of**

**the orientation**  **of these**  **fields, the**  **rotor field**  **follows the**  **stator field.**  **The rotor**  **is connected**  **to a** 

**shaft that**  **also rotates**  **and provides**  **the mechanical**  **energy output.** 

**Th e**  **purpose of**  **the technology**  **assessment is**  **to develop**  **a preliminary**  **list of**  **technology**

**options that**  **could improve**  **the efficiency**  **of small**  **electric motors.**  **In the**  **small electric**  **motors**

**w For**  **more information**  **about CEE**  **motor and**  **motor systems**  **programs, visit**  **http://www.cee1.org/ind/mot­sys/mtr**

**ms­main.php3.**

**3­29 2**  **covered in**  **this rulemaking,**  **energy efficiency**  **losses are**  **grouped into**  **four main**  **categories: I R** 

**losses, core**  **losses, friction**  **and windage**  **losses, and**  **stray load**  **losses. The**  **technology options** 

**considered in**  **this section**  **are categorized**  **by these**  **four categories**  **of losses.** 

2 3.3.1 Technology Options for I R Losses

2 **I R losses**  **stem from**  **the current**  **flow through**  **the copper**  **windings in**  **the stator**  **and**

**conductor bars**  **in the**  **rotor. These**  **conductor bars**  **are usually**  **made of**  **aluminum, but**  **some high** 

2 **efficiency motors**  **that use**  **copper are**  **now available.**  **I R losses**  **are reduced**  **by decreasing** 

**resistance to**  **current flow**  **in the**  **electrical components**  **of a**  **motor. These**  **losses are**  **manifested**

**as waste**  **heat, which**  **can shorten**  **the service**  **life of**  **a motor.** 

**Th ere**  **are several**  **ways that**  **manufacturers work**  **to minimize**  **the losses**  **created by** 

**resistance to**  **current flow.**  **Most of**  **these efforts**  **use the**  **same principle**  **of decreasing**  **resistance,**

**but there**  **are different**  **ways and**  **areas of**  **the motor**  **where this**  **can be**  **done effectively.**  **The**

**resistance of**  **a conductor**  **is a**  **function of**  **both the**  **resistivity and**  **the geometric**  **dimensions (**  e.g.

**, the**  **cross­sectional area)**  **of the**  **material through**  **which current**  **flows. Resistivity**  **is a**  **physical**

**characteristic that**  **remains relatively**  **constant for**  **a given**  **material, so**  **changing the**  **material type** 

**or manipulating**  **the material’s**  **geometry (**  e.g.

**, copper**  **wire diameter)**  **are two**  **approaches**

**manufacturers employ**  **to lower**  **resistance.**

**Ro tor**  **conductor bars**  **are areas**  **where current**  **flows. These**  **bars are**  **usually made**  **of**

**aluminum in**  **small electric**  **motors. One**  **method of**  **increasing the**  **efficiency of**  **the motor**  **is to** 

**­8 substitute**  **copper bars**  **for aluminum.**  **Aluminum has**  **a higher**  **electrical resistivity**  **(2.65 x**  **10**

**­8 ohm­m)**  **than copper**  **(1.68 x**  **10 ohm­m). Copper**  **is approximately**  **58 percent**  **more conductive** 

2 **than aluminum,**  **and changing**  **from aluminum**  **bars to**  **copper would**  **reduce associated**  **I R losses** 

**in the**  **rotor.**

**2 Manipulation**  **of the**  **rotor’s geometrical**  **design is**  **another approach**  **to reduce**  **I R losses**  **in**

**the rotor.**  **For the**  **motors covered**  **in this**  **rulemaking, the**  **rotors are**  **called “squirrel­cage**  **rotors”**

**because without**  **the core**  **steel stack,**  **the rotor**  **conductor bars**  **and end**  **rings resemble**  **the exercise** 

**wheels that**  **domesticated squirrels**  **would run**  **in. The**  **conductor bars**  **of the**  **rotor cage**  **are not** 

**straight from**  **one end**  **ring to**  **another; instead,**  **they are**  **twisted or**  **slightly skewed.**  **By skewing** 

**the rotor**  **bars, motor**  **designers can**  **reduce harmonics**  **that add**  **cusps to**  **the speed­torque** 

**characteristics of**  **the motor.**  **The cusps**  **in the**  **speed­torque curves**  **mean that**  **the acceleration**  **of**

**the motor**  **will not**  **be completely**  **smooth. The**  **degree of**  **skew matters,**  **because reducing**  **the**

**skew will**  **help reduce**  **the rotor**  **resistance and**  **reactance, thereby**  **providing gains**  **in efficiency.** 

**However, reducing**  **the skew**  **may have**  **adverse impacts**  **on the**  **speed­torque characteristics.** 

**An other**  **change to**  **the rotor**  **bar geometry**  **that can**  **reduce resistance**  **is increasing**  **the**

**cross­sectional area**  **of the**  **conductor bars.**  **Resistance is**  **inversely proportional**  **to the**  **cross**

**sectional area**  **of the**  **material (**  i.e.

**, aluminum**  **or copper)**  **through which**  **current is**  **flowing. By** 

**increasing the**  **cross­sectional area,**  **resistance will**  **decrease and**  **current flow**  **will increase.** 

**An other**  **area of**  **the rotor**  **that manufacturers**  **may alter**  **to increase**  **efficiency is**  **the end** 

**ring. Current**  **also flows**  **through this**  **area of**  **the rotor.**  **Increasing the**  **size of**  **the end**  **ring can** 

**2 help**  **decrease resistance**  **and alleviate**  **some of**  **the I R**  **losses.**

**3­3 0** **When rotor**  **resistance is**  **lowered, rotor**  **bar current**  **is increased,**  **resulting in**  **an increase**  **in**

**the electromagnetic**  **forces. Depending**  **on the**  **magnitude of**  **the gain**  **in efficiency,**  **this may** 

**actually have**  **some adverse**  **impacts on**  **the electric**  **motor. Also,**  **when manufacturers**  **increase**

**the diameter**  **of the**  **rotor bars**  **to lower**  **rotor resistance,**  **they remove**  **steel from**  **the lamination** 

**and thus**  **the magnetic**  **circuit. The**  **reduction in**  **steel will**  **drive up**  **magnetic saturation,**  **which**

**could counteract**  **the efficiency**  **gains. Furthermore,**  **changing the**  **conduct bar**  **shape could**  **induce**

**harmonic content**  **to the**  **motor’s operation.**  **Odd harmonics,**  **particularly the**  **third harmonic,**  **can**

**create cusps**  **in the**  **speed­torque characteristics,**  **which in**  **turn disrupt**  **motor acceleration.**  **Larger**

**rotor bars**  **may also**  **cause manufacturers**  **to build**  **new lamination**  **tooling and**  **add stack**  **length**

**because of**  **magnetic saturation.** 

**2 I R**  **losses are**  **also prevalent**  **in the**  **stator. There**  **are several**  **design alterations**  **that**

**manufacturers may**  **attempt to**  **decrease these**  **losses. Most**  **of the**  **design options**  **involve**

**increasing the**  **amount of**  **copper winding**  **in the**  **slots. Manufacturers**  **can accomplish**  **this by** 

**using different**  **gauges of**  **copper wire,**  **changing the**  **slot sizes,**  **and adjusting**  **the length**  **to**

**diameter ratios.**  **The use**  **of larger**  **(** i.e.

**, numerically**  **lower) wire**  **gauges increases**  **the efficiency** 

**of the**  **motor because**  **the larger**  **cross­sectional area**  **decreases the**  **overall motor**  **resistance.**

**Increasing the**  **stator’s slot**  **size may**  **also allow**  **manufacturers to**  **increase the**  **slot fill.**  **Slot fill**  **is**

**the amount**  **of copper**  **wire inserted**  **into a**  **cross­sectional area**  **relative to**  **the total**  **slot cross** 

**sectional area.**  **Depending on**  **the number**  **of poles**  **in the**  **motor, certain**  **length­to­diameter ratios** 

**are better**  **suited to**  **balance the**  **magnetic circuit.** 

**2 Another**  **way for**  **manufacturers to**  **reduce I R**  **losses is**  **to reduce**  **the air**  **gap between**  **the**

**stator and**  **rotor. A**  **smaller air**  **gap will**  **decrease the**  **magnetomotive force**  **drop, which**  **occurs**

**across the**  **air gap.**  **The motor**  **will then**  **require less**  **current to**  **drive the**  **load and**  **thereby reduce** 

**2 I R**  **losses. The**  **problem with**  **this option**  **is that**  **smaller air**  **gaps mean**  **there are**  **tighter tolerances** 

**on specifications**  **when building**  **a motor,**  **which at**  **some point**  **become technically**  **infeasible to** 

**manufacture. Based**  **on discussion**  **with manufacturers**  **and small**  **electric motor**  **design engineers,** 

**DOE believes**  **that the**  **smallest air**  **gap possible,**  **without manufacturing**  **problems, is**  **0.010 inch.** 

3.3.2 Technology Options for Core Losses

**Core losses**  **are those**  **losses created**  **in the**  **steel components**  **of a**  **motor. These**  **losses,**

**2 like**  **I R losses,**  **manifest themselves**  **as heat.**  **Core losses**  **are generated**  **in the**  **steel by**  **two**

**electromagnetic phenomena:**  **hysteresis losses**  **and eddy**  **currents. Hysteresis**  **losses are**  **caused**

**by magnetic**  **domains resisting**  **reorientation to**  **the alternating**  **magnetic field**  **(** i.e.

**, 60**  **times per** 

**second, or**  **60 hertz).**  **Eddy currents**  **are physical**  **currents that**  **are induced**  **in the**  **steel laminations** 

**by the**  **magnetic flux**  **of the**  **windings.**

**Man ufacturers**  **have several**  **techniques to**  **help reduce**  **the effects**  **of hysteresis**  **and eddy** 

**current losses**  **in their**  **motors. One**  **of the**  **first approaches**  **is simply**  **adding additional**  **steel to**  **the**

**rotor and**  **stator (**  i.e.

**, increasing**  **the “stack”**  **length). This**  **is one**  **of the**  **least costly**  **and least** 

**invasive changes**  **a manufacturer**  **can use**  **to increase**  **motor efficiency.**  **The extra**  **steel**

**laminations and**  **increased stack**  **height decrease**  **flux density.**  **This reduces**  **hysteresis losses,**  **but**

**also changes**  **motor performance.**  **Adding stack**  **length increases**  **motor impedance,**  **which is**  **then**

**reduced by**  **removing several**  **turns of**  **wire in**  **the stator.**  **Monitored starting**  **torque is**  **also**

**3­3 1** **important because**  **an increased**  **stack may**  **reduce torque,**  **rendering the**  **motor unable**  **to start**  **in**

**certain applications.**  **Adding stack**  **to the**  **motor means**  **the motor**  **is also**  **getting longer** 

**physically, therefore**  **geometrical constraints**  **can become**  **an issue**  **as well.** 

**An other**  **common technique**  **for reducing**  **steel losses**  **is using**  **a higher**  **quality, more** 

**efficient grain­oriented**  **electrical steel**  **in the**  **core. Hysteresis**  **losses are**  **reduced because**  **the**

**magnetic permeability**  **improves and**  **grain size**  **increases, reducing**  **the magnetic**  **domain**

**resistance. Eddy**  **currents are**  **reduced because**  **the resistivity**  **of the**  **laminations is**  **higher,**

**reducing the**  **magnitude of**  **the currents.**  **In studying**  **the techniques**  **used to**  **reduce steel**  **losses,**

**DOE considered**  **two types**  **of materials:**  **conventional silicon**  **steel and**  **so­called “exotic”**  **steels,**

**which contain**  **a relatively**  **high percentage**  **of boron**  **or cobalt.** 

**Co nventional**  **steels are**  **commonly used**  **in small**  **electric motors**  **manufactured today.** 

**There are**  **three types**  **of steel**  **that DOE**  **considers “conventional:”**  **cold­rolled magnetic** 

**laminations (CRML),**  **fully processed**  **non­oriented electrical**  **steel, and**  **semi­processed non** 

**oriented electrical**  **steel. Each**  **steel type**  **is sold**  **in a**  **range of**  **grades. Generally,**  **as the**  **grade**

**number goes**  **down, so**  **does the**  **amount of**  **loss associated**  **with the**  **steel (**  i.e.

**, watts**  **of loss**  **per**

**pound of**  **steel). The**  **induction level**  **also drops,**  **causing the**  **need for**  **increased stack**  **length. Of** 

**these three**  **types, CRML**  **steels are**  **the most**  **commonly used,**  **but also**  **the least**  **efficient. The** 

**fully processed**  **steels do**  **not require**  **annealing after**  **being punched**  **and assembled,**  **and are** 

**available in**  **a range**  **of steel**  **grades from**  **M56 through**  **M15. x**  **Semi­processed electrical**  **steels are** 

**8 designed**  **for annealing**  **after punching**  **and assembly,**  **but they**  **have more**  **limited availability.** 

**Th e**  **exotic steels**  **generally are**  **not manufactured**  **for specific**  **use in**  **small electric**  **motors.**

**These steels**  **include amorphous**  **steel, vanadium**  **permendur, and**  **other alloyed**  **steels containing**  **a**

**high percentage**  **of boron**  **or cobalt.**  **These steels**  **offer a**  **lower loss**  **level than**  **the best**  **electrical**

**steels, but**  **are more**  **expensive per**  **pound. From**  **a manufacturing**  **perspective, these**  **steels also** 

**present problems**  **because they**  **come in**  **non­standard thicknesses**  **that are**  **harder to**  **manufacture.**

**An other**  **method manufacturers**  **use to**  **reduce core**  **losses is**  **to use**  **thinner laminations**  **of**

**steel. Using**  **thinner laminations**  **decreases the**  **cross­sectional area**  **through which**  **the eddy** 

**currents are**  **produced, reducing**  **the magnitude**  **of the**  **eddy currents.**  **This reduction**  **in losses**  **will**

**reduce heat**  **generation in**  **the steel**  **and improve**  **efficiency. However,**  **this design**  **change does** 

**come with**  **a penalty.**  **As laminations**  **become thinner,**  **more laminations**  **are needed**  **for the**  **same**

**stack height,**  **requiring more**  **punching and**  **assembly time.** 

**Man ufacturers**  **may also**  **reduce eddy**  **currents by**  **using improved**  **insulating coatings** 

**between the**  **steel laminations.**  **Improved coatings**  **increase the**  **resistance between**  **the steel** 

**laminations, which**  **makes it**  **more difficult**  **for eddy**  **currents to**  **flow from**  **lamination to** 

**lamination.**

**An nealing**  **the core**  **steel is**  **another technique**  **manufacturers use**  **to reduce**  **hysteresis**

**losses. Annealing**  **is a**  **heating process**  **that alters**  **the grain**  **structure of**  **the steel**  **and alleviates** 

**any stresses**  **introduced during**  **punching and**  **assembly. After**  **being annealed,**  **the material** 

**x Lower**  **“M” grades**  **of steel**  **denote lower**  **losses, thus**  **M15 has**  **fewer losses**  **per pound**  **of steel**  **than M56.** 

**3­32 becomes**  **much easier**  **to magnetize,**  **which means**  **the magnetic**  **domains reorient**  **more easily.** 

**Manufacturers will**  **incur more**  **cost if**  **they anneal**  **the steel**  **because they**  **are adding**  **another step** 

**to the**  **manufacturing process,**  **which increases**  **production time.**  **The necessary**  **annealing**

**equipment also**  **requires a**  **large capital**  **investment.**

**Table 3.3.1**  **presents the**  **core steels**  **used in**  **manufacturing small**  **electric motors,** 

**including some**  **more efficient**  **steels that**  **are not**  **as common,**  **which DOE**  **considered in**  **its**

**analysis. In**  **addition to**  **the steel**  **grade name,**  **the table**  **presents nominal**  **thickness and**  **core**

**losses at**  **a fixed**  **magnetic flux**  **density.**

Table 3.3.1. Core Steel Grades, Thicknesses, and Associated Losses

Steel

Grade Nominal

Thickness

(inches) Core Loss at 60 Hz

Watts per Pound at

Magnetic Flux Density Remarks

**24 M56** * **0. 025**  **4. 30**  **Watts/lb at**  **1.5 T**  **Cold­rolled magnetic**  **laminations (semi** 

**processed)**

**26 M47**  **0. 019**  **2. 80**  **Watts/lb at**  **1.5 T**  **Non­oriented electrical**  **steel (fully**  **processed)**

**24 M36**  **0. 025**  **2. 35**  **Watts/lb at**  **1.5 T**  **Non­oriented electrical**  **steel (fully**  **processed)**

**24 M19** * **0. 025**  **2. 00**  **Watts/lb at**  **1.5 T**  **Non­oriented electrical**  **steel (fully**  **processed)**

**29 M15** * **0. 014**  **1. 45**  **Watts/lb at**  **1.5 T**  **Non­oriented electrical**  **steel (fully**  **processed)**

**Hiperco**

**50*** **0. 006**  **1. 00**  **Watts/lb at**  **1.5 T**  **Iron­co balt­vanadium**  **soft magnetic**  **alloy**

**SA1 0.**  **001 0.**  **08 Watts/lb**  **at 1.3**  **T Amorphous**  **core steel**  **(silicon and**  **boron);**

**flux density**  **limitation–testing at**  **1.3 T**  **†**

***** **Denotes a steel**  **used in**  **the engineering analysis.** 

**† Watts**  **of loss**  **per pound**  **of core**  **steel are**  **only comparable**  **at the**  **same magnetic**  **flux density,**  **measured in**  **tesla. The** 

**tesla (symbol**  **T) is**  **the SI­derived unit**  **of magnetic field,**  **which is**  **also known**  **as "magnetic flux**  **density," named**  **in honor** 

**of inventor,**  **scientist, and**  **electrical engineer**  **Nikola Tesla.**

3.3.2.1 Plastic Bonded Iron Powder

**Recently, DOE**  **became aware**  **of a**  **new technology**  **that Lund**  **University researchers**  **in**

**Sweden developed**  **in the**  **production of**  **magnetic components**  **for electric**  **motors from**  **plastic**

**bonded iron**  **powder (PBIP).**  **The technique**  **has the**  **potential to**  **cut production**  **costs by**  **50**

**percent while**  **doubling motor**  **output.**

**Th e**  **method uses**  **two main**  **ingredients: metal**  **powder and**  **plastics. Combining**  **the**

**ingredients creates**  **a material**  **with low**  **conductivity and**  **high permeability.**  **The metal**  **particles**

**are surrounded**  **by an**  **insulating plastic,**  **which prevents**  **electric current**  **from developing**  **in the** 

**material. This**  **is critical**  **because it**  **essentially eliminates**  **losses in**  **the core**  **due to**  **eddy currents.** 

**Properties of**  **PBIP can**  **differ depending**  **on the**  **processing. If**  **the metal**  **particles are**  **too closely** 

**compacted and**  **begin to**  **touch, the**  **material will**  **gain electrical**  **conductivity, counteracting**  **one of** 

**its most**  **important features.** 

**3­3 3** **Another advantage**  **of PBIP**  **is a**  **reduction in**  **the number**  **of production**  **steps. The** 

**number of**  **steps in**  **manufacturing a**  **rotor and**  **stator is**  **reduced from**  **roughly 60**  **to just**  **a few.**  **A**

**second way**  **to increase**  **savings is**  **to build**  **an inductor**  **with PBIP.**  **During processing,**  **the plastic** 

**and metal**  **are molded**  **together using**  **a centrifugal**  **force. During**  **this process,**  **the inductor**  **core**

**consisting of**  **PBIP and**  **pre­wound windings**  **are baked**  **into the**  **core. This**  **inductor is**  **then used** 

**as a**  **filter for**  **grid power**  **application. The**  **filter then**  **reduces the**  **use of**  **cooling equipment**  **in the** 

**9 motor**  **design.**

3.3.2.2 Permanent Magnet Electric Motor

**Permanent magnet**  **motors are**  **made in**  **many configurations.**  **The most**  **common are** 

**brushless DC**  **motors and**  **brushless AC**  **motors. These**  **motors use**  **a permanent**  **magnet for**  **the**

**rotating member**  **instead of**  **a squirrel­cage**  **rotor. They**  **may also**  **require an**  **electronic controller** 

**to operate,**  **which increases**  **the cost**  **of the**  **system and**  **requires extra**  **space. Permanent**  **magnet**

**motors do**  **not have**  **the same**  **operating characteristics**  **as an**  **induction motor.**  **They are**  **less**

**rugged than**  **induction motors**  **and are**  **subject to**  **conditions that**  **may cause**  **demagnetization. It**  **is**

**possible to**  **make a**  **permanent magnet**  **motor that**  **will operate**  **without the**  **aid of**  **a controller.** 

**These motors**  **are synchronous**  **in nature**  **and have**  **a different**  **speed torque**  **profile than**  **an**

**induction motor.**  **However, none**  **of these**  **motors meet**  **the requirements**  **of a**  **NEMA general** 

**purpose motor.** 

3.3.3 Technology Options for Friction and Windage Losses

**Bearing friction**  **and an**  **imperfect cooling**  **fan system**  **create what**  **is called**  **“friction and** 

**windage losses”**  **in AC**  **induction motors.**  **These losses**  **also add**  **heat to**  **the motor’s**  **system and** 

**decrease the**  **motor’s efficiency.** 

**To decrease**  **the losses**  **caused by**  **motor bearings,**  **manufacturers can**  **change the**  **bearings**

**or bearing**  **lubricant. Less**  **friction, and**  **thus less**  **heat, is**  **produced when**  **manufacturers use**  **a**

**better bearing**  **structure or**  **bearing lubricant,**  **but manufacturers**  **must also**  **consider issues**  **such as** 

**temperature rating**  **and speed.** 

**An other**  **way to**  **reduce heat**  **in an**  **induction motor**  **is to**  **use a**  **better cooling**  **system.**

**Changing the**  **fan or**  **adding baffles**  **to the**  **current fan**  **can help**  **reduce heat**  **and losses.**  **Baffles**

**help redirect**  **airflow through**  **the motor,**  **creating better**  **circulation and**  **a cooler**  **motor overall.** 

**With a**  **well­designed cooling**  **system, the**  **motor should**  **run more**  **efficiently. However,**  **some**

**manufacturers choose**  **to use**  **one cooling**  **system for**  **a range**  **of horsepower**  **ratings. This**  **means**

**that the**  **same cooling**  **system may**  **exceed spatial**  **constraints for**  **certain smaller**  **motors, resulting** 

**in more**  **losses than**  **are necessary**  **to cool**  **the motor.** 

3.3.4 Technology Options for Stray Load Losses

**2 Any**  **losses that**  **are otherwise**  **unaccounted for**  **and not**  **attributed to**  **I R losses,**  **steel**

**losses, or**  **frictional and**  **windage losses**  **are considered**  **stray­load losses.**  **DOE is**  **not aware**  **of**

**any specific**  **techniques manufacturers**  **use to**  **reduce stray­load**  **losses. General**  **process changes** 

**to the**  **manufacturing of**  **rotors and**  **stators could**  **somewhat reduce**  **these losses.** 

**3­3 4** 3.3.5 Summary of the Technology Options Under Consideration

**Table 3.3.2**  **summarizes the**  **technology options**  **discussed in**  **this technology**  **assessment,**

**and those**  **that DOE**  **will now**  **consider in**  **the screening**  **analysis (see**  **chapter 4).**  **The options**  **that**

**pass all**  **four screening**  **criteria are**  **considered “design**  **options” and**  **are used**  **in the**  **engineering**

**analysis (see**  **chapter 5)**  **as a**  **means of**  **improving the**  **efficiency of**  **small electric**  **motors.**

**.**

Table 3.3.2. Summary of Technology Options for Improving Efficiency

Type of Loss to Reduce Technology Option Applied

**Use copper**  **die­cast rotor**  **cage**

**Remo ve**  **skew on**  **conductor cage** 

**Increase cross­sectional**  **area of**  **rotor conductor**  **bars**

**I 2**  **R Losses**  **Increase end**  **ring size** 

**ch anging**  **gauges of**  **copper wire**  **in stator** 

**Man ipulate**  **stator slot**  **size**

**Decrease the**  **radial air**  **gap**

**Impro ve**  **grades of**  **electrical steel** 

**Use thinner**  **steel laminations** 

**An neal**  **steel laminations** 

**Co re**  **Losses Ad**  **d stack**  **height (**  i.e.

**, length,**  **add electrical**  **steel**

**laminations)**

**Use high­efficiency**  **lamination materials** 

**Use plastic**  **bonded iron**  **powder**

**Use a**  **permanent magnet**  **electric motor** 

**Frictio n**  **and Windage**  **Losses Use**  **better bearings**  **and lubricant** 

**In stall**  **a more**  **efficient cooling**  **system**

**3­3 5** REFERENCES

**1 U.S.**  **Small Business**  **Administration.** Small Business Size Standards Matched to North

American Industry Classification System. **2006. (Last**  **accessed April**  **21, 2008.)** 

**<http://www.sba.gov/idc/groups/public/documents/sba_homepage/serv_sstd_tablepdf.pdf> The** 

**April 21,**  **2008, material**  **from this**  **website is**  **available in**  **Docket #**  **EERE–2007–BT–STD–0007.**

**2 National**  **Electric Manufacturers**  **Association. (Last**  **accessed April**  **21, 2008.)** 

**<http://www.nema.org/about/upload/NEMACorpBrochure05.pdf >**  **The April**  **21, 2008,**  **material**

**from this**  **website is**  **available in**  **Docket #EERE–2007–BT–STD–0007.** 

**3 Small**  **Motor and**  **Motion Association.**  **January 8,**  **2008. (Last**  **accessed April**  **21, 2008.)** 

**<http://www.smma.org/> The**  **April 21,**  **2008, material**  **from this**  **website is**  **available in**  **Docket**

**#EERE–2007–BT–STD–0007.**

**4 National**  **Electric Manufacturers**  **Association.** NEMA Premium Efficiency Electric Motors

Program. **2008. (Last**  **accessed April**  **21, 2008.)** 

**<http://www.nema.org/gov/energy/efficiency/premium/upload/nemaprem1p.doc> The**  **April 21,** 

**2008, material**  **from this**  **website is**  **available in**  **Docket #EERE–2007–BT–STD–0007.** 

**5 National**  **Electric Manufacturers**  **Association.** NEMA Premium Product Scope and Nominal

Efficiency Levels. **March 12,**  **2002. (Last**  **accessed April**  **21, 2008.)** 

**<http://www.nema.org/stds/complimentary­docs/upload/MG 1MG**  **1premium.pdf> The**  **April**

**21, 2008,**  **material from**  **this website**  **is available**  **in Docket**  **#EERE–2007–BT–STD–0007.**

**6 Consortium**  **for Energy**  **Efficiency.** Industrial Programs Premium­Efficiency Motors

**. 2008.** 

**(Last accessed**  **April 21,**  **2008.) <**  **http://www.cee1.org/ind/motrs/motrs­main.php3> The**  **April**

**21, 2008,**  **material from**  **this website**  **is available**  **in Docket**  **#EERE–2007–BT–STD–0007.**

**7 Consortium**  **for Energy**  **Efficiency.** Energy­Efficiency Incentive Programs, Premium­Efficiency

Motors and Adjustable Speed Drives in the U.S. and Canada

**. May**  **2007.**

**< http://www.**  **motorsmatter.org/tools/programs2007.pdf >** 

**8 National**  **Materials.** National Materials Company: Materials

**. (Last**  **accessed April**  **21, 2008.)** 

**<http://nmlp.hypermart.net/Material/index.html> The**  **April 21,**  **2008, material**  **from this**  **website**

**is available**  **in Docket**  **#EERE–2007–BT–STD–0007.**

**9 Horrdin,**  **H., Olsson,**  **E.** Technology Shifts in Power Electronics and Electric Motors for

Hybrid Electric Vehicles: A Study of Silicon Carbide and Iron Powder Materials. **2007.**

**Chalmers University**  **of Technology.**  **Göteborg, Sweden.** 

**3­3 6**