CHAPTER 5. ENGINEERING ANALYSIS

TABLE OF CONTENTS`

5.1 INTRODUCTION

.............................................................................................................. 1

5.2 PRODUCT CLASSES AND BASELINE MOTORS ANALYZED

................................. 2

5.2.1 Product Classes Analyzed

....................................................................................... 2

5.2.2 Baseline Models

...................................................................................................... 9

5.3 ENGINEERING ANALYSIS METHODOLOGY

........................................................... 10

5.3.1 Subcontractor Software Design Approach

............................................................ 10

5.3.2 Market Motor Validation

...................................................................................... 12

5.4 COST MODEL

................................................................................................................. 13

5.4.1 Constructing a Bill of Materials

............................................................................ 14

5.4.2 Commodity Prices

................................................................................................. 15

5.4.3 Labor Costs and Assumptions

............................................................................... 17

5.4.4 Manufacturer Markups

.......................................................................................... 19

5.5 RESULTS OF ENGINEERING ANALYSIS

.................................................................. 19

5.5.1 Polyphase, 1 Horsepower, 4-Pole, 56-Frame Motor

............................................. 20

5.5.2 Capacitor-Start, Induction-Run, 1/2 Ho rsepower, 4-Pole, 48-Frame Motor

........ 22

5.5.3 Capacitor-Start, Capacitor-Run, 3/4 Hors epower, 4-Pole, 56-Frame Motor

........ 25

5.6 SCALING RELATIONSHIPS

......................................................................................... 29

5.6.1 Market Efficiency Data

......................................................................................... 29

5.6.2 Independently Tested Motor Results

..................................................................... 29

5.6.3 Modeling Small Electric Motor Efficiency

........................................................... 30

5.6.4 Scaling of the Motor Losses Data

......................................................................... 31

5.6.5 CSCR Motor Scaling

............................................................................................. 32

5-iLIST OF TABLES

Table 5.2.1. Representative Units Selected fo r the Determination Analysis

.............................. 2

Table 5.2.2. Representative Units Selected for the Preliminary Analysis

.................................. 3

Table 5.2.3. Representative Units Selected for the Notice of Proposed Rulemaking

................. 8

Table 5.2.4. Efficiency Ratings of Baseline Motors Selected for Analysis

................................ 9 Table 5.4.1. Labor Markups for Small Elect ric Motor Manu facturers

..................................... 18

Table 5.5.1. Efficiency and MSP Data for Polyphase Motor

.................................................... 21

Table 5.5.2. Polyphase, 1 Horsepower, 4-Pole, 56-Frame Motor Designs

............................... 22

Table 5.5.3. Efficiency and MSP Data for Capacitor-Start, Induction-Run, 48-Frame Motor. 24

Table 5.5.4. Capacitor-Start, Induction-Run, 1/2 Horsepower, 4-Pole, 48-Frame Motor Designs

.................................................................................................................. 25

Table 5.5.5. Efficiency and MSP Data for Capa citor-Start, Capacitor-Run Motor

.................. 27

Table 5.5.6. Capacitor-Start, Capacitor-Run, 3/4 Hors epower, 4-Pole, 56-Frame Motor

........ 28

LIST OF FIGURES

Figure 5.2.1. Polyphase Small Electric Motor Shipments Broken Down by Pole Configuration

............................................................................................................................... 3 Figure 5.2.2. Polyphase Small Electric Motor Shipments Broken Down by Horsepower

......... 4

Figure 5.2.4. Capacitor-Start, Inducti on-Run Small Electric Motor Shipments Broken Down

Figure 5.2.5. Capacitor-Start, Inducti on-Run Small Electric Motor Shipments Broken Down

Figure 5.2.6. Models of Capacitor-Start , Induction-Run Small Electric Motors Broken Down

Figure 5.2.7. Capacitor-Start, Capacitor-Run Small Electric Motor Shipments Broken Down

Figure 5.2.8. Capacitor-Start, Capacitor-Run Small Electric Motor Shipments Broken Down

Figure 5.2.9. Models of Capacitor-Start , Capacitor-Run Small Electric Motors Broken Down

Figure 5.5.1. Polyphase 1 Horsepower, 4-Pole, 56-Frame Motor Engineering Analysis, with

Figure 5.5.2. Polyphase 1 Horsepower, 4-Pole, 56-Frame Motor Engineering Analysis,

Figure 5.5.3. Capacitor-Start, Induction-Run, 1⁄2 Hors epower, 4-Pole, 48-Frame Engineering Figure 5.2.3. Models of Polyphase Small Electric Motors Broken Down by Horsepower

........ 4

by Pole Configuration

........................................................................................... 5

by Horsepower

...................................................................................................... 5

by Horsepower

...................................................................................................... 6

by Pole Configurations

.......................................................................................... 7

by Horsepower

...................................................................................................... 7

by Horsepower

...................................................................................................... 8 Figure 5.4.1. Standard Method of Cost Accoun ting for Standards Rulemaking

...................... 13 Figure 5.4.2. Five-Year Copper Wire Prices in $2008 US

....................................................... 16 Figure 5.4.3. Five-Year Die-Casting Prices in $2008 US

........................................................ 16 Figure 5.4.4. Five-Year Steel Lamination Prices in $2008 US

................................................ 17

Maximum Technology Point

............................................................................... 20

without Maximum Technology Point

.................................................................. 21

Analysis Curve, with Maximum Technology Point

............................................ 23

5-iiFigure 5.5.4. Capacitor-Start, Induction-Run, 1⁄2 Hors epower, 4-Pole, 48-Frame Engineering Analysis Curve, without Maximum Technology Point

....................................... 23 Figure 5.5.5. Capacitor-Start, Capacitor-Run 3⁄4 Horse power, 4-Pole, 56-Frame Engineering

Figure 5.5.6. Capacitor-Start, Capacitor-Run 3⁄4 Horse power, 4-Pole, 56-Frame Engineering Analysis Curve, with Maximum Technology Point

............................................ 26

Analysis Curve, without Maximum Technology Point

....................................... 26 Figure 5.6.1. Manufacturer Motor Losses for Polyphase Motors

............................................. 31 Figure 5.6.2. Manufacturer Motor Losses for CSIR Motors

.................................................... 31 Figure 5.6.3. Four Pole CSIR Efficiency vs. Four Pole CSCR Efficiency

............................... 32

5-iiiLIST OF ACRONYMS AND ABBREVIATIONS

AWG American wire gauge

BOM Bill of materials CSCR Capacitor-Start, Capacitor-Run Motor CSIR Capacitor-Start, Induction-Run Motor DOE United States Department of Energy EISA Energy Independence and Security Act M* M15, M19, M56 - grade of core steel MSP Manufacturer Selling Price

MPC Manufacturer Production Cost

NEMA National Electrical Manufacturers Association NCI Navigant Consulting, Inc RPM Revolutions per minute TSD Technical Support Document SEC Securities and Exchange Commission

U.S. United States

μ F Microfarads

5-ivCHAPTER 5. ENGINEERING ANALYSIS

5.1 INTRODUCTION

The engineering analysis estimates the increase in manufacturer selling price (MSP) associated with technological and design changes that improve the efficiency of small electric motors. This chapter presents the U.S. De partment of Energy’s (DOE’s) assumptions, methodology and findings for the small electric mo tor engineering analysis. The output from the engineering analysis is a “cost-efficiency” relationship for each motor analyzed which describes how cost changes as efficiency increases. The engi neering analysis is used as an input to the lifecycle cost analysis (see Techni cal Support Document (TSD) chapter 8) as well as the national impact analysis (see TSD chapter 10).

As discussed in chapter 3 of this TSD, the electric motors covered in this rulemaking include general-purpose capacito r-start, induction-run (CSIR), capacitor-start, capacitor-run (CSCR), and polyphase electric motors built in a National Electrical Manufacturers Association (NEMA) two-digit frame number series. The engineering analysis selected and analyzed one small electric motor from each of these three categories of covered motors.

The engineering analysis takes input from the market and technology assessment (see TSD chapter 3) and the screening analysis (s ee TSD chapter 4). These inputs include product classes, baseline motor performance, methods for improving efficiency, and design options that have passed the screening criteria. The engineer ing analysis uses these inputs, coupled with material price estimates, design parameters, and other manufact urer inputs, to develop the relationship between the MSP and nominal full-load efficiency of the representative motors studied. For small electric motors, this relati onship was evaluated using third-party design software, created and maintained by Yeadon Energy Systems, Inc.

At its most basic level, the output of the engineering analysis is a curve that estimates the manufacturer’s selling price for a range of efficien cy values. This output is subsequently markedup to determine the end-user prices based on th e various distribution ch annels (see TSD chapter 6). After determining customer prices by appl ying distribution chain markups, sales tax, and contractor markups, the data is combined with the energy-use and end-use load characterization (see TSD chapter 7) and used as a critical input to the custome r’s life-cycle cost and payback period analysis (see TSD chapter 8).

The results presented in this chapter do not provide a full assessment of the manufacturer’s costs associated with increasing efficiency levels for a small electric motor. The relationship presented in this chapter assume s an ideal situation, where manufacturers do not incur any costs associated with retooling, produ ct redesign, training, or marketing associated with incorporating design changes to their product lines to achieve the efficiency levels presented. DOE has quantified the additional costs manufacturers would incur when complying with mandatory efficiency standards using the design specifications outlined in this chapter. For

a discussion of those costs and DOE’s methodol ogy for quantifying them, see TSD chapter 12, the manufacturer impact analysis.

5-1In this chapter, DOE discusses the product classes analyzed and the representative motors

selected from all covered small electric motors. DOE also presen ts the methodology, inputs, and results associated with the development of M SP versus efficiency curves for each of the representative motors. Finally, DOE discusses the approach used to scale the engineering analysis to all other product classes for the national impact analysis.

5.2 PRODUCT CLASSES AND BASELINE MOTORS ANALYZED

Due to the large number of product classes, DOE did not directly analyze all covered motors. Instead, DOE selected representative units from the 72 product classe s of small electric motors based on three factors: (1) the motors that were studied in the determination and preliminary analyses, (2) manufacturer’s sales catalogs for this equipment, and (3) the ability to

scale from these units to other units.

5.2.1 Product Classes Analyzed

In the determination analysis, DOE studied five different motors as the representative units. Two of the motors were capacitor-start, in duction-run and three were polyphase. For the capacitor-start, induction-run motors, DOE chose two similar models with 56 and 48 frame series to capture different cost-efficiency charact eristics associated with frame series. For the polyphase motors, DOE chose three models, holdi ng frame series constant, but varying the horsepower for two motors. The five motors studi ed in the determination analysis are presented

in Table 5.2.1.

Table 5.2.1. Representative Unit s Selected for the De termination Analysis

Motor Category Model Horsepower Number of Poles Frame series

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

In the preliminary analysis engineering analysis, DOE studied four motors: two CSIR motors, one CSCR motor, and one polyphase motor. The two CSIR motors analyzed had the same pole configuration and horsepower ratings, but were built in different frame series. The CSCR and polyphase motors were at incremen tal horsepower ratings above the two CSIR motors. The four motors studied in the pr eliminary analysis are presented in Table 5.2.2.

5-26-Pole

7%

4-Pole

68% 2-Pole

25% Table 5.2.2. Representative Unit s Selected for the Pr eliminary Analysis
Motor Category Horsepower Number of Poles Frame series

CSIR 0.50 4 48

CSIR 0.50 4 56

CSCR 0.75 4 56

Polyphase 1.0 4 56

As mentioned, DOE also reviewed manufacture r catalogs. Also, DOE created a database of over 700 models that represent all the small electric motors manufactured and listed in the catalogs. Although this database does not provi de information on unit sa les, it does provide an indication of the more popular motors from the st andpoint of having a greater variety of certain combinations of horsepower and fra me series. Analyzing this da ta and shipments data enabled DOE to select popular configurati ons of small electric motors.

Figure 5.2.1 through Figure 5.2.9 show ship ments data for each motor category broken down by pole configuration and horsepower, as we ll as the number of models of each motor category broken down by horsepower

Figure 5.2.1. Polyphase Small Electric Motor Shipments Broken Down by Pole Configuration

5-31/4 hp

2% 1/3 hp

5% 1/2 hp

11%

3/4 hp

28%

1 hp

19% 1.5 hp

28% 2 hp

5% 3 hp

2%

0 10 20 30 40 50 60 70 80 90

0.25 0.33 0.50 0.75 1.00 1.50 2.00 3.00Number of Models

Horsepower Figure 5.2.2. Polyphase Small Electric Motor Shipments Broken Down by Horsepower

Figure 5.2.1 and Figure 5.2.2 are based on projected shipments da ta for the National Impacts Analysis (see chapter 6 for more detail on the development of these data). They show the breakdown of shipments by pole configuratio n and horsepower. An overwhelming majority of polyphase motors shipped are four-pole mach ines and the weighted average horsepower of shipments is 1 horsepower.

Figure 5.2.3. Models of Polyphase Small Electric Motors Broken Down by Horsepower

The data in Figure 5.2.3 are based on DOE’s database of small elec tric 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 1⁄2 horsepower, but

the data show a skew toward models around 1 ho rsepower. This data reaffirm the weighted

5-46-Pole

26%

4-Pole

38% 2-Pole

36%

1/4 hp

18%

1/3 hp

30%

1/2 hp

25% 3/4 hp

22% 1 hp

4% 1.5 hp

1% 2 hp

0% 3 hp

0% average of 1 horsepower for polyphase motor shipments, which is why DOE selected 1 horsepower for the polyphase representative unit.

Figure 5.2.4. Capacitor-Start, Induction-Run Small Electric Motor Shipments Broken Down by Pole Configuration

Figure 5.2.5. Capacitor-Start, Induction-Run Small Electric Motor Shipments Broken Down by Horsepower

Figure 5.2.4 and Figure 5.2.5 are based on projected shipments da ta for the National Impacts Analysis (see chapter 6 for more detail on the development of these data). They show

5-50 20 40 60 80 100 120 140 160

0.25 0.33 0.50 0.75 1.00 1.50 2.00 3.00Number of Models

Horsepower the breakdown of shipments by pole configura tion and horsepower. Th e pole configuration distribution is fairly even among two, four, and six poles, but four pole motors are still the most common. The weighted average horsepower of CSIR motors shipped is 1⁄2 hp.

Figure 5.2.6. Models of Capacitor-Start, Induction-Run Small Electric Motors Broken Down by Horsepower

The data in Figure 5.2.6 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 which reaffirms the weighted av erage of 1⁄2 horsepower for CSIR shipments. Therefore, DOE selected a rating of 1⁄2 horse power for the CSIR representative unit.

5-66-Pole

9%

4-Pole

67% 2-Pole

24%

1/4 HP

2% 1/3 HP

6% 1/2HP

6%

3/4 HP

27%

1 HP

12% 1.5 HP

24% 2 HP

19% 3 HP

4% Figure 5.2.7. Capacitor-Start, Capacitor-Run Small Electric Motor Shipments Broken Down by Pole Configurations

Figure 5.2.8. Capacitor-Start, Capacitor-Run Small Electric Motor Shipments Broken Down by Horsepower

Figure 5.2.7 and Figure 5.2.8 are based on pr ojected shipments data for the National Impacts Analysis (see chapter 6 for more detail on the development of these data). These figures show the breakdown of shipments by pole configuration and horsepower. The pole

5-70 5 10 15 20 25 30 35

0.25 0.33 0.50 0.75 1.00 1.50 2.00 3.00Number of Models

Horsepower configuration distribution shows that four pol e motors are the most common. The weighted average horsepower of CSCR motors shi pped is between 1 and 11⁄2 horsepower.

Figure 5.2.9. Models of Capacitor-Start, Capaci tor-Run Small Electric Motors Broken Down by Horsepower

The weighted average horsepower of CS CR motors shipped was between 1 and 11⁄2 horsepower, but the most common horsepower mode l was 3⁄4 horsepower, shown in Figure 5.2.9. DOE did not want to choose another representativ e unit with a 1 horsepower rating and felt that a rating of 11⁄2 horsepower could overly skew the sca ling results by over-representing the high end of the range of horsepower ratings. Therefore, DOE selected its CSCR representative unit to have a horsepower rating of 3⁄4, which was the same as the most common model.

Table 5.2.3 presents the three representative un its DOE selected for this NOPR analysis. All of the motors are four-pole motors and, in vi ew of DOE’s analysis of manufacturer catalogs, this is the most common configuration for these horsepower ratings. DOE selected motors that approximate the middle of the range of covered ho rsepower ratings, partly to minimize any error that might be introduced as the efficiency of th ese motors are extrapolated to other horsepower ratings.

Table 5.2.3. Representative Units Se lected for the Notice of Proposed Rulemaking
Motor Category Horsepower Number of Poles Frame series

Polyphase 1.00 4 56

CSIR 0.50 4 48

CSCR 0.75 4 56

DOE identified these three as representative units of interest. All three units fit the requirements of a NEMA general-purpose, single speed, induction motor, rated for continuous duty, and built with open construction in a two-digit frame series. DOE provides additional

5-8detail on each motor, including input voltage, base line efficiency, and other critical performance

characteristics in the section that follow.

DOE decided to only consider the minimum frame number series in each product class when determining efficiency standards. Ther efore, the baseline motors listed in Table 5.2.4 represent the minimum available frame size in th eir respective product class. There is more

detail on the reason for this decision in section 5.6.

5.2.2 Baseline Models

For each representative product class select ed, DOE identified a specific motor as a fundamental design against whic h it would apply changes to improve the motor’s efficiency.

These small electric motors were considered DOE’s baseline models. DOE chose these small electric motors to represent the characteristics of the least efficient motor for each analyzed product class. Because there are no existing minim um energy conservation standards for small electric motors, the baseline efficiency was selected after reviewing efficiency ratings suggested by manufacturers in the preliminary analyses and product available in the current market. Table

5.2.4 below shows the efficiencies that DOE found and used as baseline efficiency ratings. Each efficiency level listed below is the tested efficiency of a particular motor that DOE purchased, tested, and modeled in its subc ontractor’s software program.

Table 5.2.4. Efficiency Ratings of Baseline Motors Selected for Analysis

Basic Characteristics of Motors Analyzed Baseline Efficiency %

Polyphase, 1 hp, 4-pole, 56 frame 77.2*

CSIR, 1⁄2 hp, 4-pole, 48 frame 57.7

CSCR, 3⁄4 hp, 4-pole, 56 frame 71.0

*The motor purchased was listed at 74%, but was tested at 77.2%.

As mentioned, DOE tested each motor that was purchased and to be used as a baseline model. DOE contracted an independent, accredite d laboratory, Advanced Energy, as well as its technical expert, Yeadon Energy Systems, to pe rform the appropriate IEEE test procedure for

each motor. DOE established dimensional and performance specifications in addition to efficiency for the baseline models by examinin g all outputs of the IEEE test procedures and performing teardowns of the purchased motors. Th e results of the IEEE test procedures provided several motor performance characteristics including speed, power factor, torque, and line current at various load points. After compiling this test data, DOE’s technical expert tore down each motor to obtain dimensions, copper wire gauges, steel grade, and any other pertinent design information. Finally, the purchased motors were modeled in the designer’s software and used as the baseline designs in each analyzed product class for the engineering analysis. Again, the three product classes that were analyzed were: CS IR, 1⁄2 horsepower, 4-pole; CSCR, 3⁄4 horsepower, 4­ pole; and polyphase, 1 horsepower, 4-pole motors . Specific detail on these baseline motors is provided in the results section of this chapter, section 5.5.

5-95.3 ENGINEERING ANALYSIS METHODOLOGY

DOE conducted the engineering analysis using a modified design-option approach where DOE employed its technical expert, with motor design software, to develop motor designs at several efficiency levels for each analyzed produ ct class. Based on these simulated designs and manufacturer and component supplier data, DOE calculated manufacturing costs and selling prices associated with each efficiency level. DOE decided on this approach after receiving insufficient response to its request for the manufacturer data needed to execute an efficiencylevel, approach for the preliminary analyses. The design-option approach allows DOE to make its engineering analysis methodologies, assump tions, and results publicly available, granting advocates, manufacturers, and other interested parties the opportunity to review and comment on this information. The design options consider ed in the engineering analysis include: using copper die-cast rotor, reducing skew on stack, incr easing cross-sectional area of rotor conductor bars, increasing end-ring size, changing the gaug e of copper wire in stat or, manipulating stator slot dimensions, decreasing air gap between roto r and stator to 12.5 thousandths of an inch, improving grades of electrical steel, using thi nner steel laminations, annealing steel laminations, adding stack height, using high efficiency lamin ation materials, changing run-capacitor ratings, installing better ball bearings and lubricant, and installing a more efficient cooling system.

DOE’s technical expert, who specializes in small electric motor designs, prepared six sets of designs, two sets for each motor analyzed with each set spanning a range of efficiency levels. The third-party software design company determin ed the fundamental design parameters of the baseline motors through the aforementioned testing and teardowns. After modeling the baseline motors and creating theoretical, more efficient designs, DOE attempted to validate the results of the engineering analysis with the testing and teardown of additional motors available in the

current market.

5.3.1 Subcontractor Software Design Approach

DOE worked with a subcontractor to deve lop MSP-efficiency curves for the three representative small electric motors. As discu ssed above, DOE retained a small electric motor
expert a with design experience and software, who prepared multiple sets of designs with increasing efficiency. The contractor started by testing the baseline motors purchased according to the applicable IEEE test procedure, both I EEE 112 test methods A and B were performed for the polyphase motor and IEEE 114 for the two single -phase motors. After testing the motors, the subcontractor tore down the motor, measured va rious dimensions, counted the steel laminations, examined the slot fill, and determined all other pertinent design parameters. This data was combined and used as inputs to the design software. The resulting designs served as the baseline models for each product class analyzed and veri fied the validity of the experts proprietary software program. As new designs were create d, careful attention was paid to the critical performance characteristics to ensure that the resulting designs were reasonable and manufacturable replacements of the baseline mo tors. To this end, DOE established a set of design limitations that are applied across all six sets of designs.

a Yeadon Energy Systems, Inc. (YES) of Iron Mountain, Michigan.

5-10However, there is one design limitation that is an exception, stack height, and DOE uses this design option as a sensitivity analysis. Half of the design sets follow a limitation of no more than a 20% increase in stack height, while the othe r half follow another less stringent restriction of no more than a 100% increase in stack height . Both restrictions are listed below and the following list presents the all of the design limitations DOE imposed.

Additionally, one performance characteristic that DOE did not set a limitation on was thermal viability. DOE did not do so because the baseline designs for this analysis were created by validating actual motors in production today, whereas in the preliminary analysis they were theoretical designs. So, for the increasingly efficient, theoretical, designs, DOE assumed that the thermal viability would remain because as the efficiency level increases, less heat needs to dissipate within the motor and therefore the materials are not subjected to the same strains.

• Peak slot fill – the minimum value of th is parameter should exceed 50% while the maximum value should not reach more than 65% for an assumed high volume simultaneous insertion process. (Note: DOE considers “slot fill” to be the area of the wire (including insulation) divided by th e total slot area available for winding.)

• Air gap between rotor and stator – the air ga p between the rotor and stator should not be less than 0.0125 inches for any design. Having air gaps tighter than this minimum could be problematic and may cause contact between the spinning rotor and the stationary stator, especially as shaft length increases.

• Stator slot opening – the slot opening width in combination with the copper wire gauges used should graph to a point in the “Level Wind Area” of the “Blade Gap Chart” taken from Alliance Winding 1 . Without this restriction, DOE is concerned there may be too many issues with wire breakage and jamming of manufacturers’ winding tools.

• Locked-rotor torque – for single-phase motors , the locked-rotor torque must be kept within 10 percent of the baseline motor, and be within the specifications set forth by NEMA MG1-1987 in Section 12.32.2. For pol yphase motors there are no NEMA specifications, therefore the designs must maintain the locked-rotor torque within 10% of

the baseline model.

• Locked-rotor current – for single-phase mo tors, the locked-rotor current should not exceed the values of NEMA MG1-1987 Section 12.33.2 (Design N). For polyphase motors, the locked-rotor current should not exceed the values shown in NEMA MG1­ 1987 Section 12.37 for Design B medium moto rs. Although there are no requirements for small polyphase motors, DOE found that these standards are commonly used in the industry.

• Breakdown torque – for single-phase motors, the breakdown torque must fall within

NEMA MG 1-1987 Table 10-5 limits for all ratings. For polyphase motors, the breakdown torque should follow the guidelin es established in NEMA MG1-1987 Section

12.37.

5-11• Power factor – the power factor of the base line motor should be maintained or increased for all designs.

• Speed at rated load – the speed of the base line motor should be maintained or increased for all designs.

• Service factor – the service factor of each de sign should be within the limits set forth in

NEMA MG1-1987 Table 12-2.

• Stray load loss – the assumed value of stray load loss should be 1.8%.

• Motor diameter – the motor diam eter of the baseline motor s hould be that of the baseline and remain constant for all designs.

• Cooling system – the parameters directly related to the motor’s cooling system, such as ventilation openings in the laminations, shoul d not be modified in a manner that will increase the operating temperature of the motor.

• Rotor skew – the rotor skew may be altered, but it cannot be raised or lowered to a point

that will introduce harmonics that a dversely affect motor performance ( e.g. completely removing it) or introduce cusps in the acceleration curve. (Note: this design limitation is subjective and relies on the design of the baseline motor and the expertise of the designer).

• Stack height – as mentioned before, DOE’s expert prepared two sets of designs for each motor analyzed. The first set of designs for each motor allows a maximum increase in stack height of 20% relative to the baseline. The second set of designs are less restricted and allow a 100% increase in stack height ( i.e. the stack height may double the original value).

Working within these parameters, the subcontr actor prepared eight to nine designs of increased efficiency for each of the two design sets for each representative motor. The design levels prepared for the space constrained designs were at the baseline, intermediate levels, a level for a design using a copper rotor, and a max-t ech level with a design using a copper rotor and exotic core steel. The non-space constrained design (100% increase of stack height) efficiency levels corresponded to the efficiency levels created for the space-constrained designs.

5.3.2 Market Motor Validation

After DOE created its theoretical designs, DOE attempted to validate those results with data from motors currently available in the small electric motors market. DOE selected two to three motors from each representative product class, each with a different catalog listed efficiency level. DOE then had its subcontractor perform testing on these motors to verify its efficiency level. Next, the motors were torn down and a bill of materials was constructed and marked up to create an MSP using the same pric ing scheme developed an d discussed in section

5.4. The results of the test data and the MSP developed from the tear downs of these motors

5-12Direct

Labor Direct

Material Overhead Selling General &

Admin. R & D Interest Full Cost of Produc t were plotted along with the curves of the theo retical designs developed for the representative units. DOE found that the data points at comparable efficiency levels were consistent with the curves of the theoretical designs. The results of this validation analysis are illustrated along with the curves developed for the analyzed product classes in appendix 5A.

5.4 COST MODEL

DOE uses a standard method of cost accoun ting to determine the costs associated with manufacturing. This methodology is illustrated in Figure 5.4.1, where production costs and nonproduction costs are combined to deter mine the manufacturer selling price (MSP).

Indirect Labor

Indirect Material

Maintenance

Depreciation

Taxes

Insurance related

to assets Mkt . research

A dvertising

POS promotion

Sales person salary + travel
+ commission

Logistics - Warehousing - Delivery

- Record keeping - Order entry/ processing Costs of Costs
service & associated o f
staff units with efforts borrowing

General corporate or improved

costs - comp. etc. production to find new

products or

processes Costs

funds

* Tax Reform Act of 1986, essentially, requires companies to measure cost of goods sold as the full production cost of the goods sold. Code compliance

Modernization Cust . service Selling General &

Admin. R & D Interest Non-Production Cost

Direct

Labor Direct

Material Overhead Full Production Cost* (Manufacturer Production Cost) Manufacturer Selling Price

Figure 5.4.1. Standard Method of Cost Acco unting for Standards Rulemaking

DOE developed estimates of some of the cost multipliers shown in Figure 5.4.1 by reviewing Security and Exchange Commission (SEC) SEC-10K reports from A.O. Smith Corporation, Baldor Electric Company, Emers on Motor Technologies, Re gal-Beloit Corporation, and WEG Electric Corporation as well as through conversations with indus try experts. Together, the full production cost or manufacturer produc tion cost (MPC) and the non-production costs equal the MSP. Full production cost is a combina tion of direct labor, di rect materials, and overhead. The overhead contributing to full produc tion cost includes indi rect labor, indirect material, maintenance, depreci ation, taxes, and insurance re lated to company assets. Nonproduction costs include the cost of selling (marke t research, advertising, sales representatives,

5-13logistics), general and administrative costs, research and development, interest payments and profit factor (not shown in the figure).

After the subcontractor designs were completed and verified for manufacturability ( i.e.

, following the design limitations mentioned in secti on 5.3.1), the next step was applying this cost model to all of them. A standard bill of materials (BOM) was constructed that includes direct material costs and labor time estimates along with costs. The BOM is then multiplied by a markup for overhead to obtain an MPC which in turn is marked up again for non-production

costs to create a MSP.

5.4.1 Constructing a Bill of Materials

The BOM calculated for each design contained three types of material costs: fixed costs, variable costs, and semi-fixed costs. Fixed co st materials are those components that remain constant across all designs within a set. That is, these are the parts that do not vary with efficiency, such as switches, ba ll-bearings and other components. The aggregate fixed cost will vary from one motor category to another because the different motor categories have different component lists, but for a given motor category the total fixed costs re main constant for all designs. The variable costs considered are those portions of the BOM that vary based on the cost

of the material and the amount of that material us ed in the design. For example, stator and rotor lamination costs are variable costs because the material price for the different steel grades changes as does the volume of steel needed for each design. Finally, semi-fixed costs are those materials that have a constant price, but vary in cost from design to design as a function of the amount used in the motor designs. An example of this is the cost of the die-cast aluminum or copper rotor bars. The price per pound for alumin um or copper is the same from design to design; however, the cost per design is different because the amount of metal used for die-casting the rotor bars varies depending upon the design ( e.g. a longer motor will require more aluminum).

DOE presents a detailed bill of materials for one design from each of the three motor categories analyzed in TSD appendix 5A. The di scussion below describe s the level of detail contained in the bill of materials presented in this appendix.

Each item in the BOM is organized by the component of the motor to which they apply. For example “end cap assembly” is a heading an d under this label ther e are several itemized parts with associated costs. The BOM includes the following headings, each with an itemized parts list: stator assembly, ro tor assembly, end cap assembly, housing assembly, hardware, and final assembly.

As mentioned, each heading has an itemized list of components. The stator assembly’s itemized lists include prices for cleats, lead wires, capacitor wires (for appropriate motor categories), splices, insulation, slot liner, copper sh ipping, stator laminati ons, main and auxiliary (when applicable) copper wire costs. The rotor assembly portion of the BOM includes prices for a fan, bearings, the rotor aluminum or copper, and the lamination costs. The housing assembly list includes paint, a fan shroud, a base, and the actual housing costs. Much of the hardware costs are fixed and include prices for washers, capac itor covers (when applicable), mounting bolts, cap screws, thermal switch screws, terminal block screws, terminal cover screws, studs, conduit cap,

5-14a start switch (when applicable), a nameplate, as well as some variable costs for start and run capacitors (when applicable).

5.4.2 Commodity Prices

A significant portion of the costs associated with small electric motors is attributed to the fluctuating metal prices of se veral motor components. These include steel laminations, copper wiring, and rotor die-casting aluminum or copper. DOE understands that it is difficult to choose an accurate price point for these components because their underl ying commodity prices have seen great fluctuations over the past several years, translating into large variations in cost. As a best estimate for these prices, DOE used an inflation adjusted five-year average price point for these components. In calculating the five-y ear average prices for these commodities, DOE adjusted historical prices to $2008 using the hist orical Bureau of Labor Statistics Producer Price Indices (PPI) for each commodity’s industry 2

.

Additionally, DOE performed a cost sensitivity analysis in which they examined both a high and low commodities cost scenario. For all commodity prices, DOE used the PPI to determine the high and low cost points and then input those component costs into the model. This allowed DOE to generate a high commodities case and a low commodities case for the engineering analysis results. Please see appendix 5A for greater detail on the high and low cost

scenarios.

DOE utilized the PPI for each commodity’s industry to calculate these prices. The PPI is an index that tracks the average change in pr ices that domestic produc ers receive for their product. This allowed DOE to scale its current 2008 component prices back for the previous five years for an inflation adjusted comparison. Once DOE had prices for 2004 through 2008, it was able to take a five-year average of these prices, as well as determine the maximum and minimum prices over the time period. The following figu res depict the component prices over the fiveyear timeframe.

5-15$2.20 $2.30 $2.40 $2.50 $2.60 $2.70 $2.80 $2.90 $3.00 $3.10 $3.20

2003 2004 2005 2006 2007 2008 2009$/lb

Year Copper Wire Prices (in 2008 US$)

18 Gauge

19 Gauge

20 Gauge

21 Gauge

22 Gauge

$0.00 $0.50 $1.00 $1.50 $2.00 $2.50

2003 2004 2005 2006 2007 2008 2009$/lb

Year Copper

Aluminum Figure 5.4.2. Five-Year Copper Wire Prices in $2008 US

Figure 5.4.3. Five-Year Die-Casting Prices in $2008 US

5-16$0.00 $0.05 $0.10 $0.15 $0.20 $0.25 $0.30 $0.35 $0.40 $0.45

2003 2004 2005 2006 2007 2008 2009$/lam

Year Core Steel Stator Prices (in 2008 US$)

29M15

24M19

24M56

Figure 5.4.4. Five-Year Steel Lamination Prices in $2008 US

5.4.3 Labor Costs and Assumptions

Due to the degree of automation used in manufacturing small electric motors, labor costs are not a significant portion of the overall produc tion cost and do not vary significantly with increasingly efficient designs. The modeling software provides an estimate of the amount of labor associated with each small electric motor design. DOE then multiplies that time estimate by a marked up hourly rate to determine the pr oportion of labor cost associated with the manufacturer’s production cost.

DOE used the same hourly labor rate for all motors analyzed. The base hourly rate was developed from the 2002 Ec onomic Census of Industry 3 by the U.S. Census Bureau. Several markups were applied succe ssively and with cumulative effect to the base hourly rate to obtain a fully burdened rate which was inte nded to be representative of the labor costs associated with manufacturing these motors. Table 5.4.1 shows th e base labor rate DOE started with, each markup with its corresponding markup percentage and the resulting partiall y burdened rate after that markup, and a final fully burde ned labor rate. The markups we re applied in the order they appear in the table and to the “rate per hour” liste d for the previous markup. For example, the 28 percent markup for fringe was applied to the $18.02 ( i.e. , 1.28 x $18.02 = $23.07) that DOE obtained after marking up the base labor ra te by 33 percent for indirect production.

5-17Table 5.4.1. Labor Markups for Small Electric Motor Manufacturers
Item description Markup Rate per hour

Labor cost per hour ٭ $ 13.55

Indirect Production ٭٭ 33 % $ 18.02

Fringe† 28 % $ 23.07

Assembly Labor Up-time†† 43 % $ 32.99

Cost of Labor Input to Spreadsheet $ 32.99

published December 2004, Table 2002 Economic Census of Industry, Cost per hour is from U.S. Census Bureau, ٭ 5, page 5. Data for NAICS code 3353121 “Fractional Horsepower Motors” Production workers hours and wages. Indirect Production Labor (Production managers, quality cont rol, etc.) as a percent of direct labor on a cost basis. ٭٭ Navigant Consulting, Inc. NCI estimate. † Fringe includes pension contributions, group insurance premiums, workers compensation. Source: U.S. Census
Bureau, 2002 Economic Census of Industry , published December 2004, Table 3, page 3. Data for NAICS code 335312 “Motors and generator manufacturing,” total fringe benefits as a percent of total compensation for all employees (not just production workers). †† Assembly labor up-time is a factor applied to account for the time that workers are not assembling product and/or reworking unsatisfactory units. The markup of 43 percent represents a 70 percent utilization (multiplying by 100/70). NCI estimate.

As discussed above, the small electric motor design software provides an estimated manufacturing time for each design. The softwa re apportions the labor time estimates into categories that identify an overall activity, such as stator assembly, rotor assembly, and housing assembly. Within these categories, subheadings denote process steps for specific parts of the motor. Summing the list of process steps gives a total time estimate for manufacturing the motor, which is multiplied by the fully burdened labor cost, shown as $32.99.

In consultation with manufacturers, DOE l earned that the amount of time necessary to build a motor with a longer stack or more copper wirings is considered negligible. Therefore, there was only one process step that DOE calculate d as a variable labor cost, namely the “Rotor Core Assembly” process. This activity change d to a longer time when the subcontractor’s designs called for a copper rotor. The reason fo r the increased labor time is because copper has a higher melting point than aluminum does, so die-casting the rotor takes more time to heat the metal sufficiently.

The remainder and the majority of the labor costs calculated were fixed costs. The following categories are associated with the labor estimates: stator assembly, rotor assembly, end cap assembly, housing assembly, hardware, an d final assembly. The stator assembly list includes time estimates for punching and stacking the laminations, adding slot liner, winding coils, inserting coils, forming end-turns, lead st ripping and terminal placement, magnet wire or lead splicing, using the stator test system, a nd applying the varnish. Adding the fan, machining the shaft, pressing the shaft onto the rotor, bala ncing the rotor, and heat shrinking bearings onto the shaft are labor steps for the rotor assembly. For end cap assembly there are time estimates for machining the bearing bore at each end, pressing the cap, washing, and performing the die-cast press. The labor times under the ha rdware section are estimates of adding the components to the motor. Various washers, bolts, studs, screws, gr ommets for capacitor wire (when applicable), start and/or run capacitors (w hen applicable), and a start sw itch (when applicable) are among

5-18these hardware components. Included in the fina l assembly section are times for actual assembly, motor testing, labeling and packaging.

5.4.4 Manufacturer Markups

DOE used the three markups described below to account for costs that are part of each motor leaving a manufacturer’s facility. Scrap factors, overhead costs, and non-production markups will vary from manufacturer to manufacturer because their profit margins, prices paid for goods, and business structures vary. DOE prepared estimates for these three non-production cost manufacturer markups from SEC-10K reports and conversations w ith manufacturers and
experts.

• Handling and scrap factor: 2.5 percent markup. This markup was applied to the direct material production costs of each motor. It acc ounts for the handling of material (loading into assembly or winding equipment) and the scrap material that cannot be used in the production of a finished small electric motor ( e.g. , lengths of wire too short to wind).

• Factory overhead: 17.5 or 18.0 percent markup. Factory overhead includes all the indirect costs associated with production, i ndirect materials and energy use, taxes, insurance, and depreciation. DOE applies f actory overhead to the direct material production costs, including the handling and scrap factor, and labor estimates. For aluminum rotor designs a 17.5 percent markup was used, but for all copper rotor designs an 18.0 percent markup was used to factor in increased depreciation for the equipment.

• Non-production: 45 percent markup. This markup reflects costs including sales and general administrative, research and developm ent, interest payments, and profit factor. DOE applies the non-production markup to the sum of the direct material production, the handling and scrap, the direct labor, and the factory overhead otherwise known as the MPC. The MPC plus the non-production ma rkup gives a manufacturer selling price

MSP.

5.5 RESULTS OF ENGINEERING ANALYSIS

For the polyphase and CSIR motors analyz ed, DOE developed eigh t efficiency levels using a motor design software tool, and for the CSCR motor analyzed DOE developed nine efficiency levels. These included a baseline desi gn, intermediate designs, then a copper rotor design, and a max-tech design that uses a copper rotor and an exotic core steel. Then by using the methodology and pricing scheme outlined in the previous section, DOE developed manufacturer selling prices for each small elec tric motor design created. Throughout this section, DOE shows the bottoms-up derived MSP’s.

The engineering analysis results are essentially six manufacturer selling price-versus-fullload efficiency curves that represent two re lationships for each of the three representative product classes analyzed. For each of the three motors analyzed, DOE created designs that allowed stack height to double and designs that only allowed stack height to increase by 20 percent over the baseline design. This wa s done to determine how the cost-efficiency

5-19$0 $200 $400 $600 $800 $1,000 $1,200 $1,400 $1,600 $1,800 $2,000

76 78 80 82 84 86 88 90Manufacturer Selling Price ($2008)

Full Load Efficiency (%) Space Constrained

Non-Space
Constrained relationship would change for space constraine d OEMs (only 20 percent increase) versus nonspace constrained OEMs (doubled stack height maximum). Thus, each of the three motors analyzed have two curves plotted to depict these two scenarios. The six graphs shown in Figure

5.5.1 through Figure 5.5.6 provide the MSP versus efficiency curves and Table 5.5.1 through Table 5.5.6 present the tabulated results.

5.5.1 Polyphase, 1 Horsepower, 4-Pole, 56-Frame Motor

Figure 5.5.1 presents the relationship between the MSP and full-load efficiency for the polyphase motor analyzed. DOE developed an exotic maximum technology (max-tech) design using a non-traditional steel type ( i.e. , Hiperco 50 TM ) that makes the motor considerably more expensive than other designs analyzed. Use of this premium electromagnetic steel greatly increases the MSP of the motor, thereby skewing the Y-axis. For this reason, the engineering analysis results are presented twice, first with the max-tech design (Figure 5.5.1) and then again without the max-tech design (Figure 5.5.2).

Figure 5.5.1. Polyphase 1 Horsepower, 4-Pole, 56-Frame Motor Engineering Analysis, with Maximum Technology Point

5-20$0 $50 $100 $150 $200 $250 $300 $350

76 78 80 82 84 86 88 90Manufacturer Selling Price ($2008)

Full Load Efficiency (%) Space Constrained

Non-Space
Constrained

Figure 5.5.2. Polyphase 1 Horsepower, 4-Pole, 56-Frame Motor Engineering Analysis, without Maximum Technology Point

Table 5.5.1 presents the same engineering anal ysis results in a tabular form, including the full-load efficiency values and the MSPs. Moving from the baseline motor to the max-tech motor, DOE found that the full-load efficiency would increase 11.1 percentage points, for a 14.5­ percent improvement over the baseline motor. Raising the efficiency to that level caused the MSP to more than triple, increasing from$97.74 for the baseline model to $324.66 for the nonspace constrained max-tech motor. The difference in MSP is even greater for the spaceconstrained max-tech moto r, which has a MSP of $1,770.27.

Table 5.5.1. Efficiency and MSP Data for Polyphase Motor

Efficiency Level Efficiency % (Design 1 / Design 2)* MSP $ (Design 1 / Design 2)*

Baseline 77.2 % $ 97.74

EL 1 78.7 % $ 103.81

EL 2 80.0 % $ 107.01

EL 3 81.6 % $ 112.88

EL 4 82.5 % $ 117.01

EL 5 85.2 % / 85.2 % $ 229.84 / $ 150.86

EL 6 86.7 % / 86.4 % $ 236.20 / $ 184.73

EL 7 (Max-tech) 88.3 % / 88.4 % $ 1,770.27 / $ 324.66

*Design 1 denotes the space constrained design, and design 2 denotes the non-space constrained design. If only one value is listed, then the space constrained design is the same as the non-space constrained design.

5-21Table 5.5.2 presents some of the design a nd performance specificati ons associated with the eight polyphase designs presented above. Additionally, DOE provi des more details and performance characteristics for polyphase designs in appendix 5A.

Table 5.5.2. Polyphase, 1 Horsepower, 4-Pole, 56-Frame Motor Designs

Parameter

(Units) Baseline EL1 EL2 EL3 EL4 EL5 EL6 EL7

- - Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Efficiency (%) 77.2 78.7 80.0 81.6 82.5 85.2

85.2 86.7

86.4 88.3

88.4

Power

Factor 71.6 71.3 71.9 74.2 73.8 71.8

74.7 72.4

74.5 71.9

72.0 Speed (RPM) 1714 1728 1726 1720 1724 1719

1722 1736

1728 1736

1753 Torque (in-lbs) 36.8 36.7 36.8 36.7 36.6 36.7

36.8 36.6

36.6 36.6

35.6

Current

(A) 3.38 3.35 3.29 3.10 3.08 3.06

2.96 3.00

2.92 2.97

2.91

Core Steel 24M56 24M56 24M56 24M56 24M56 29M15

24M19 29M15

24M19 Hiperco 50

29M15 Stack Height (in) 3.0 3.2 3.425 3.5 3.6 3.6

4.45 3.6

6 3.6

5.525

Rotor

Material Al Al Al Al Al Al

Al Cu

Al Cu

Cu

Main Wire

(AWG) 22 21 20.5 20 19.5 19.5

21 19.5

20 19.5

20 LR Torque

(in-lbs) 76.1 79.1 80.3 73.4 73.0 81.0

77.1 63.7

80.6 63.7

72.7

LR Current (A) 16.6 17.5 17.3 15.8 16.1 16.4

16.2 16.3

17.0 16.3

19.5

Service

Factor 1.15 1.15 1.15 1.15 1.15 1.15

1.15 1.15

1.15 1.15

1.15 *Design 1 denotes the space constrained design, and design 2 denotes the non-space constrained design. If only one value is listed, then the space constrained design is the same as the non-space constrained design.

5.5.2 Capacitor-Start, Induction-Run, 1/2 Horsepower, 4-Pole, 48-Frame Motor

Figure 5.5.3 presents the relationship between the MSP and full-load efficiency for the 48-frame capacitor-start, induction-run motor DOE an alyzed. The max-tech design incorporates a high-grade non-traditional elect romagnetic steel (Hiperco 50 TM ) alloy that is much more expensive than the high quality electromagnetic st eel alloy used in any of the other designs. Use of such steel greatly increases the MSP of the motor, thereby skewing the Y-axis. For this reason, the engineering analysis results are pres ented again without the max-tech design in Figure 5.5.4.

5-22$0 $200 $400 $600 $800 $1,000 $1,200 $1,400

55 60 65 70 75 80Manufacturer Selling Price ($2008)

Full Load Efficiency (%) Space Constrained

Non-Space
Constrained

$75 $95 $115 $135 $155 $175 $195

55 60 65 70 75 80Manufacturer Selling Price ($2008)

Full Load Efficiency (%) Space Constrained

Non-Space
Constrained Figure 5.5.3. Capacitor-Start, Induction-Run, 1⁄2 Horsepower, 4-Pole, 48-Frame Engineering Analysis Curve, with Maximum Technology Point

Figure 5.5.4. Capacitor-Start, Induction-Run, 1⁄2 Horsepower, 4-Pole, 48-Frame Engineering Analysis Curve, without Maximum Technology Point

Table 5.5.3 presents the same engineering anal ysis results in a tabular form, including the full-load efficiency values and the MSPs. Moving from the baseline motor to the max-tech

5-23motor, DOE found that the full-load efficiency would increase 19.3 percentage points, for about a 33-percent improvement over the baseline motor. Raising the efficiency to that level caused the MSP to increase by more than 65 percent, increasing from $91.04 for the baseline model to $150.70 for the non-space constrained max-tech motor. The difference in MSP is significantly greater for the space-constrained max-tech motor, which has a MSP of $1,204.30.

Table 5.5.3. Efficiency and MSP Data for Capa citor-Start, Induction-Run, 48-Frame

Motor

Efficiency Level Efficiency % (Design 1 / Design 2)* MSP $ (Design 1 / Design 2)*

Baseline 57.7 % $ 91.04

EL 1 59.5 % $ 95.62

EL 2 62.0 % $ 98.54

EL 3 64.2 % $ 99.78

EL 4 68.5 % / 68.6 % $ 114.57 / $ 107.19

EL 5 71.2 % / 71.2 % $ 118.98 / $ 120.53

EL 6 73.0 % / 73.1 % $ 182.28 / $ 132.16

EL 7 (Max-tech) 77.0 % / 77.2 % $ 1,204.30 / $ 150.70

*Design 1 denotes the space constrained design, and design 2 denotes the non-space constrained design. If only one value is listed, then the space constrained design is the same as the non-space constrained design.

Table 5.5.4 presents some of the design a nd performance specificati ons associated with the eight CSIR efficiency levels presented a bove. Additionally, DOE pr ovides more details and performance characteristics for CSIR designs in appendix 5A.

5-24Table 5.5.4. Capacitor-Start, Induction-Run, 1/2 Horsepower, 4-Pole, 48-Frame Motor Designs

Parameter

(Units) Baseline EL1 EL2 EL3 EL4 EL5 EL6 EL7

- - Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Design 1 Design 2 Efficiency (%) 57.7 59.5 62.0 64.2 68.5

68.6 71.2

71.2 73.0

73.1 77.0

77.2

Power

Factor 59.4 59.2 59.4 62.1 61.5

67.3 59.6

68.6 62.0

62.0 67.2

65.3 Speed (RPM) 1723 1722 1722 1722 1723

1732 1749

1735 1739

1744 1736

1760 Torque (in-lbs) 18.4 18.3 18.5 18.5 18.3

18.5 18.0

18.2 18.2

18.1 18.3

17.9

Current

(A) 9.12 8.84 8.48 7.85 7.53

6.77 7.42

6.32 7.07

6.91 6.26

6.27

Core Steel .028M56 24M56 24M56 24M56 24M19

24M56 24M19

24M56 29M15

24M19 Hiperco 50

24M19 Stack Height (in) 2 2.1 2.2 2.3 2.4

2.9 2.4

4 2.4

3.275 2.4

4

Rotor

Material Al Al Al Al Al

Al Cu

Al Cu

Al Cu

Cu

Main Wire

(AWG) 18.5 21 20.5 20.5 20.5

20 20.5

21 20.5

21 20.5

21

Aux. Wire

(AWG) 21.5 21.5 21.5 21.5 21.5

21.5 21.5

21.5 21.5

21.5 21.5

21.5 Start Cap. ( μ F) 333 333 333 333 333 333 333 333

LR Torque

(in-lbs) 51.0 50.2 50.6 50.2 50.6

52.6 50.7

51.6 50.1

50.7 51.6

47.6

LR Current (A) 38.0 37.4 37.4 35.9 35.3

35.3 36.0

34.9 34.3

39.2 32.1

35.9

Service

Factor 1.25 1.25 1.25 1.25 1.25

1.25 1.25

1.25 1.25

1.25 1.25

1.25 *Design 1 denotes the space constrained design, and design 2 denotes the non-space constrained design. If only one value is listed, then the space constrained design is the same as the non-space constrained design.

5.5.3 Capacitor-Start, Capacitor-Run, 3/4 Horsepower, 4-Pole, 56-Frame Motor

Figure 5.5.5 presents the relationship between the MSP and full-load efficiency for the CSCR motor. The max-tech design incorporates a high-grade non-trad itional electromagnetic steel alloy (Hiperco 50 TM ) that is much more expensive than the high quality electromagnetic steel alloy used in any of the other designs. Use of such steel greatly increases the MSP of the motor, thereby distorting the Y-axis. For this reason, the engineering analysis results are presented again without the max-tech design in Figure 5.5.6.

5-25$0 $200 $400 $600 $800 $1,000 $1,200 $1,400 $1,600 $1,800 $2,000

70 75 80 85 90Manufacturer Selling Price ($2008)

Full Load Efficiency (%) Space Constrained

Non-Space
Constrained

Figure 5.5.5. Capacitor-Start, Capacitor-Run 3⁄4 Horsepower, 4-Pole, 56-Frame Engineering Analysis Curve, with Maximum Technology Point

$375

$325

$275

$225

$175

$125

$75 Space Constrained

N on

- Space
Constrained

70 75 80 85 90

Manufacturer Sell in g Price ($2008) Full Load Efficiency (%)

Figure 5.5.6. Capacitor-Start, Capacitor-Run 3⁄4 Horsepower, 4-Pole, 56-Frame Engineering Analysis Curve, without Maximum Technology Point

5-26Table 5.5.5 presents the same engineering anal ysis results in tabular form, including the full-load efficiency values and the MSPs. Moving from the baseline motor to the max-tech motor, DOE found that the full-load efficiency would increase 16.3 percentage points, for about a 23-percent improvement over the baseline motor. Raising the efficiency to that level caused theMSP to more than triple, increasing from $110.82 for the baseline model to $353.50 for the nonspace constrained max-tech motor. The difference in MSP is significantly greater for the spaceconstrained max-tech moto r, which has a MSP of $1,778.48.

Table 5.5.5. Efficiency and MSP Data for Capa citor-Start, Capacitor-Run Motor

Efficiency Level Efficiency % (Design 1 / Design 2)* MSP $ (Design 1 / Design 2)*

Baseline 71.0 % $ 110.82

EL 1 74.3 % $ 116.06

EL 2 78.3 % / 78.4 % $ 136.22 / $ 128.60

EL 3 80.3 % / 80.5 % $ 141.49 / $ 133.71

EL 4 81.6 % / 81.8 % $ 145.27 / $ 141.10

EL 5 82.7 % / 82.9 % $ 152.88 / $ 149.23

EL 6 83.7 % / 83.5 % $ 237.53 / $ 156.85

EL 7 85.4 % / 85.6 % $ 245.36 / $ 172.75

EL 8 (Max-tech) 87.3 % / 87.3 % $ 1,778.48 / $ 353.50

*Design 1 denotes the space constrained design, and design 2 denotes the non-space constrained design. If only one value is listed, then the space constrained design is the same as the non-space constrained design.

Table 5.5.6 presents some of the design a nd performance specificati ons associated with the nine CSCR efficiency levels presented a bove. Additionally, DOE provides more design details and performance characteris tics for CSCR designs in appendix 5A.

5-27Table5.5.6. Capacitor-Start, Capacitor-Run, 3/4 Horsepower, 4-Pole, 56-Frame MotorParameter(Units)BaselineEL1EL2EL3EL4EL5EL6EL7EL8-Design 1Design 2Design 1Design 2Design 1Design 2Design 1Design 2Design 1Design 2Design 1Design 2Design 1Design 2Design 1Design 2Efficiency(%)71.074.378.378.480.380.581.681.882.782.983.783.585.485.687.387.3PowerFactor68.677.175.183.980.183.490.79692.295.994.699.293.197.590.699.4Speed(RPM)1735174017421731174217351744175317691763173317601762176517641755Torque(oz-ft)27.427.327.227.327.427.427.227.127.027.027.327.126.926.626.927.1Current(A)10.18.538.307.407.667.296.586.236.406.166.165.926.185.786.175.64CoreSteel24M5624M5624M1924M5624M1924M5624M1924M5624M1924M5629M1524M5629M1524M19Hiperco 5029M19Stack Height(in)33.153.34.13.454.63.64.53.653.65.53.64.753.66Rotor MaterialAlAlAlAlAlAlAlCuCuCuAlCuCuCuCuCuMain Wire(AWG)1820.520.520.52021.52021.52021.52021.52021.52021.5Aux. Wire(AWG)1921.521.521.52121212121211921192121.521Start Cap.(μF)433433433433433433433433433433433433433433433433Run Cap.(μF)7.5202020252535354040404545453545LR Torque(oz-ft)76.477.778.085.581.178.377.675.679.076.871.673.871.776.477.271.6LR Current(A)53.253.154.347.354.334.652.147.158.444.745.245.047.443.947.842.9Service Factor1.251.251.251.251.251.251.251.251.251.251.251.251.251.251.251.25*Design 1 denotes the space constrained design, and design 2 denotes the non-space constrained design. If only one value is listed, then the space constraineddesign is the same as the non-space constrained design.5-285.6 SCALING RELATIONSHIPS

In order to reduce the analytical burden associated with conducting a detailed engineering analysis of the cost-efficiency relationshi p on all 72 product classe s, DOE developed a systematic approach that reduced the number of small electric motors it analyzed while retaining reasonable levels of accuracy. DOE selected one baseline model from each motor category to evaluate in the engineering analysis. It then extrapolated the results of this analysis from the units studied to the other product classes. This section describes the methodology DOE followed to scale to product classes that were not directly analyzed.

To scale to the product classes that were not analyzed, DOE followed a few steps. First, DOE compiled efficiency data for as many manufact urers and product classes as possible. Then the data was filtered to ensure an accurate representation of the small electric motors that are covered by the statute. Next, DOE modeled the efficiency data in terms of motor losses to fill in any potential gaps in data. An independently accredited laboratory validated the efficiency data by testing certain small electric motors accordin g to the applicable IEEE test procedures: IEEE 112 (test methods A and B) for polyphase motors and IEEE 114 for single-phase motors. Finally, DOE scaled the results of the engineering analysis based on the relationships found from the combined catalog and test data.

5.6.1 Market Efficiency Data

To determine the existing efficiency re lationships between product classes, DOE examined all the publicly available efficiency data for small electric motors covered by this rulemaking. DOE compiled available catalog da ta and online listings for polyphase, CSIR, and CSCR motors to see how efficiency changes ac ross different pole configurations and with varying horsepower ratings. DOE developed a database of over 3,000 motors built in a NEMA two-digit frame sizes. This database was filtered to create a comprehensive list of motors that met the statutory definition of a small electric motor. DOE also filtered the database to only include efficiency data for the smallest frame series seen for each product class. The smallest frame series for a given product class is the most restricted frame series in terms of possible efficiency. The reason for this is that there is less room there is to add core material (in terms of diameter), which helps increase efficiency, therefore any efficiency the smallest frame series motor can achieve should also be achievable for the larger frame series in the same product class. Additionally, individual manufacturer motor lines were examined independently so that design characteristics ( e.g. steel grade) would be consistent. Since each manufacturer was looked at individually, if a manufacturer did not have a nearly complete product line, or if the manufacturer did not provide enough efficiency da ta to create an accurate assessment of the product line, then that manufacturer’s data was no t included in the initial efficiency relationship

data set.

5.6.2 Independently Tested Motor Results

At the time of this data collection and analysis, there were no energy-efficiency standards or mandated test procedures for small electric motors. Therefore, when one manufacturer lists

5-29y 32.479x 0.402

R2 0.9463

y 31.591x 0.482

R2 0.9777 y 31.352x 0.328

R2 0.9845

10 100

0.1 1 10Motor Losses

Horsepower Rating Market Average Motor Losses for Polyphase Motors

Two Pole

Four Pole

Six Pole efficiency in their catalog it was not necessarily calculated and reported in the same way that

another manufacturer calculates a nd reports it. So, DOE contracted an independently accredited electric motor testing company. In addition to using catalog data and online listings to determine the existing efficiency relationship between product classes, DOE purchase d and tested a sample product line of polyphase and CSIR motors to ve rify efficiency relationships. DOE was unable to purchase and test a complete product line of CSCR motors becau se no manufacturers currently offer a complete product line of this motor category. This issue is discussed further in Section

5.6.5 dealing with CSCR scaling. This data was intended to validate the efficiency relationships seen across product classes, not necessarily to confirm the value of efficiency listed by the

manufacturer. Results of this tes ting are available in appendix 5A.

5.6.3 Modeling Small Electric Motor Efficiency

After compiling the catalog and test data, DOE modeled the data and began drawing

conclusions about the relations hip between product class and efficiency. To do this DOE converted efficiency into motor losses using the equation: (100/ μ ) – 1, where μ is full-load efficiency. By converting the efficiency data into motor losses, DOE could generate the most accurate line of best fit. DOE used a power equation to model motor losses and then plotted the results, for each manufacturer, on graphs with l ogarithmic axes. Using the generated equations, DOE interpolated and extrapolated the catalog and test data to approximate data for any gaps of information. This allowed DOE to generate co mplete sets of data, a set being the 24 product classes within a motor category. After modeling motor losses for the various manufacturers’ data, DOE aggregated the data to obtain an average picture of motor losses (and therefore efficiency) for the current market. The aggregat ed results are shown in Figure 5.6.1 and Figure

5.6.2. The plots show that the data can be gra phed linearly, which eases in terpretation of trends

in motor losses.

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‐

‐

5-30y 47.57x 0.395

R2 0.9857

y 41.784x 0.474

R2 0.9952 y 37.342x 0.725

R2 0.9918

10 100

0.1 1 10Motor Losses

Horsepower Rating Market Average Motor Losses for CSIR Motors

Two Pole

Four Pole

Six Pole Figure 5.6.1. Manufacturer Motor Losses for Polyphase Motors

= ‐

=

= ‐

= = ‐

= ‐

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Figure 5.6.2. Manufacturer Motor Losses for CSIR Motors

Each figure is unique for a certain motor category and each figure contains three lines, one for each pole configuration. Also, the graphs shown are of the aggregated market data, but DOE did create these graphs for each manufacturer for which efficiency data was compiled. Prior to aggregating the indivi dual manufacturer data, DOE used the equations of the lines of best fit to interpolate and extr apolate any missing motor loss data for a given product class. For example, if manufacturer A did not produce a polyphase, two pole 1⁄4 horsepower motor, DOE could use an equation, unique to manufacturer A and polyphase, two-pole motors to estimate what the motor losses would be. This process was used to fill in any gaps in a manufacturer’s product line so that a manufacturer’s motor loss table would be completely filled out. This process was implemented for all manufacturers where there was enough data to interpret a complete product line. Genera ting data to create complete product lines for the various manufacturers was necessary to prevent uneven waiting of manufacturer trends. DOE understands that each manufacturer targets di fferent performance char acteristics that can ultimately affect the efficiency of the motor. Therefore, DOE estimated what motor losses, and thus efficiency, would be for mo tors that are not necessarily produced by some manufacturers.

5.6.4 Scaling of the Motor Losses Data

Once DOE generated a market picture of motor losses for each motor category, DOE developed an approach to scale the results of the three product classes analyzed in the engineering analysis. This meant scaling to the other 69 product classes for each efficiency level, or design, that DOE created. DOE normalized the motor losses of the market to

5-31correspond to the value of the baseline efficien cy level for the three representative product classes. For example, DOE compared the average motor losses of the market for a 1 horsepower, four pole, polyphase motor to th e motor losses of the baseline design DOE developed in the engineering analysis for that sa me motor. DOE found the percentage change in motor losses between those two motors and applied that same percentage change to the remaining product classes for polyphase motors, t hus creating a baseline motor loss level for all polyphase product classes. This c onstituted a shift up in motor losses, but down in efficiency. After the initial shift down in efficiency, DOE incremented the aggregate market data by the percentage change seen from one efficiency level to the next. This constituted seven or eight shifts down in motor losses, but up in efficiency and resulted in comparable efficiency levels for all product classes at all efficiency levels, for a given motor category.

5.6.5 CSCR Motor Scaling

The scaling methodology outlined above was u tilized separately for polyphase and CSIR motors using product line data for each of those motor categories. For CSCR motors, however, there was not enough information available to id entify efficiency relationships between product classes. This is because manufacturers do not currently make CSCR motors for all of the horsepower and pole configuration combinations th at DOE uses to define its product classes. Currently, most manufacturers only make four pole CSCR motors, so DOE compared these four pole CSCR product lines to the manufacturer’s corresponding four pole CSIR product lines. DOE found that the relationships, or changes in ef ficiency relative to horsepower, appeared to be the same for both motor categories, but the effici ency of CSCR motors was shifted higher. This relationship can be seen in Figure 5.6.3.

Figure 5.6.3. Four Pole CSIR Efficiency vs. Four Pole CSCR Efficiency

In light of the parallel efficiency relati onship between CSCR and CSIR motors, and the fact that very limited CSCR motor data is available, DOE decided to base its CSCR efficiency scaling on available CSIR data. Thus, DOE utilized the same motor losses tables it used for

5-32CSIR scaling when performing scaling for CSCR motors. However, rather than scaling based on the percentage change of the four pole 0.50 horsepower product class, as was done for the CSIR motors, DOE performed scaling based on the percentage change in the four pole 0.75 horsepower product class, which was the repr esentative product class analyzed for CSCR

motors.

5-33REFERENCES

1 Design Considerations to Optimize Stator Manufacturing, Alliance Winding Equipment, Inc., Ft. Wayne, Indiana. Blade-Gap Chart.

2 U.S. Department of Labor, Bureau of Labor Sta tistics, Producer Price Indices. Last accessed April 12, 2009. <http://www.bls.gov/ppi>.

3 U.S. Census Bureau, 2002 Economic Census of Industry Series Reports for Industry, US Department of Commerce, 2003.

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