5-i 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 Horsepower, 4-Pole, 48-Frame Motor ........ 22

5.5.3 Capacitor-Start, Capacitor-Run, 3/4 Horsepower, 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 ............................................................................................. 325- ii LIST OF TABLES

Table 5.2.1. Representative Units Selected for 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 Electric Motor Manufacturers ..................................... 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 Capacitor-Start, Capacitor-Run Motor .................. 27

Table 5.5.6. Capacitor-Start, Capacitor-Run, 3/4 Horsepower, 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 5.2.3. Models of Polyphase Small Electric Motors Broken Down by Horsepower ........ 4 Figure 5.2.4. Capacitor-Start, Induction-Run Small Electric Motor Shipments Broken Down

by Pole Configuration ........................................................................................... 5 Figure 5.2.5. Capacitor-Start, Induction-Run Small Electric Motor Shipments Broken Down

by Horsepower ...................................................................................................... 5 Figure 5.2.6. Models of Capacitor-Start, Induction-Run Small Electric Motors Broken Down

by Horsepower ...................................................................................................... 6 Figure 5.2.7. Capacitor-Start, Capacitor-Run Small Electric Motor Shipments Broken Down

by Pole Configurations .......................................................................................... 7 Figure 5.2.8. Capacitor-Start, Capacitor-Run Small Electric Motor Shipments Broken Down

by Horsepower ...................................................................................................... 7 Figure 5.2.9. Models of Capacitor-Start, Capacitor-Run Small Electric Motors Broken Down

by Horsepower ...................................................................................................... 8 Figure 5.4.1. Standard Method of Cost Accounting 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 Figure 5.5.1. Polyphase 1 Horsepower, 4-Pole, 56-Frame Motor Engineering Analysis, with

Maximum Technology Point ............................................................................... 20 Figure 5.5.2. Polyphase 1 Horsepower, 4-Pole, 56-Frame Motor Engineering Analysis,

without Maximum Technology Point .................................................................. 21 Figure 5.5.3. Capacitor-Start, Induction-Run, 1⁄2 Horsepower, 4-Pole, 48-Frame Engineering

Analysis Curve, with Maximum Technology Point ............................................ 235- iii

Figure 5.5.4. Capacitor-Start, Induction-Run, 1⁄2 Horsepower, 4-Pole, 48-Frame Engineering

Analysis Curve, without Maximum Technology Point ....................................... 23 Figure 5.5.5. Capacitor-Start, Capacitor-Run 3⁄4 Horsepower, 4-Pole, 56-Frame Engineering

An alysis Curve, with Maximum Technology Point ............................................ 26 Figure 5.5.6. Capacitor-Start, Capacitor-Run 3⁄4 Horsepower, 4-Pole, 56-Frame Engineering

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 ............................... 325- iv LIST 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 μF Microfarads5-1 CHAPTER 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. Department of Energy’s (DOE’s ) assumptions, methodology and findings for the small electric motor engineering analysis. The output from the engineering analysis is a “cost

- efficiency” relationship for each motor analyzed which describeshow cost changes as efficiency increases. The engineering analysis is used as an input to the lifecycle cost analysis (see Technical 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 capacitor-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 ch apter 3) and the screening analysis (see 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 engineering analysis uses these inputs, coupled with material price estimates, design parameters, and other manufacturer inputs, to develop the relationship between the MSP and nominal full-load efficiency of the representative motors studied. For small electric motors, this relationship 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 efficiency value s. This output is subsequent ly mark ed

up to determine the end-user prices based on the various distribution channels (see TSD chapter 6). After determining customer prices by applying 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 customer’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 assumes an ideal situation, where manufacturers do not incur any costs associated with retooling, product 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 tho se costs and DOE’s methodology for quantifying them, see TSD chapter 12, the manufacturer impact analysis.5-2

In this chapter, DOE discusses the product class es an alyzed and the representative motors selected from all covered small electric motors. DOE also presents the methodology, inputs, and results associated with the development of MSP versus efficiency curves for each of the representative motors. Finally, DOE discusses the approach used to scale the engineering analysis to all other product class es for the national impact analysis.

5.2 PRODUCT CLASS ES 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 classes 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, induction-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 characteristics associated with frame series. For the polyphase motors, DOE chose three models, holding frame series constant, but varying the horsepower for two motors. The five motors studied in the determination analysis are presented

in Table 5.2.1

.

Table 5.2.1. Representative Units Selected for the Determination 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 3N 102 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 incremental horsepower ratings above the two CSIR motors. The four motors studied in the preliminary analysis are presented in Table 5.2.2

.5-3

Table 5.2.2. Representative Units Selected for the Preliminary 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 manufacturer 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 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 series. Analyzing this data and shipments data enabled DOE to select popular configurations of small electric motors.

Figure 5.2.1 through Figure 5.2.9 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

Figure 5.2.1. Polyphase Small Electric Motor Shipments Broken Down by Pole Configuration5-4

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 data 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 configuration and horsepower. An overwhelming majority of polyphase motors shipped are four-pole machines 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 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 1⁄2 horsepower, but

the data show a skew toward model s around 1 horsepower. This data reaffirm the weighted5-5

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-R un Small Electric Motor Shipments Broken Down by Pole Configuration

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

Figure 5.2.4 and Figure 5.2.5 are based on projected shipments data for the National Impacts Analysis (see chapter 6 for more detail on the development of these data). They show5-6

the breakdown of shipments by pole configuration and horsepower. The 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 average of 1⁄2 horsepower for CSIR shipments. Therefore, DOE selected a rating of 1⁄2 horsepower for the CSIR representative unit.5-7

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

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

Figure 5.2.7 and Figure 5.2.8 are based on projected shipments data for the National Impacts Analysis (see chapter 6 for more detail on the development of these data). The se figures show the breakdown of shipments by pole configuration and horsepower. The pol e5-8

configuration distribution shows that four pole motors are the most common. The weighted average horsepower of CSCR motors shipped is between 1 and 11⁄2 horsepower.

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

The weighted average horsepower of CSCR motors shipped was between 1 and 11⁄2 horsepower, but the most common horsepower model was 3⁄4 horsepower, shown in Figure 5.2.9

. DOE did not want to choose another representative unit with a 1 horsepower rating and felt that a rating of 11⁄2 horsepower could overly skew the scaling 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 units DOE selected for this NOPR analysis. All of the motors are four-pole motors and, in view 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 horsepower ratings, partly to minimize any error that might be introduced as the efficiency of these motors are extrapolated to other horsepower ratings.

Table 5.2.3. Representative Units Selected 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 continuou s duty, and built with open construction in a two-digit frame series. DOE provides additional5-9

detail on each motor, including input voltage, baseline 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. Therefore, the baseline motors listed in Table 5.2.4 represent the minimum available frame size in their 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 selected, DOE identified a specific motor as a fundamental design against which it would apply changes to improve the moto r’s efficiency

. These small electric motors were considered DOE’s baseline model s. 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 minimum 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 subcontractor’s software progr am.

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 fra me 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, accredited laboratory, Advanced Energy, as well as its technical expert, Yeadon Energy Systems, to perform the appropriate IEEE test procedure for each motor. DOE established dimensional and performance specifications in addition to efficiency for the baseline models by examining all outputs of the IEEE test procedures and performing teardowns of the purchased motors. The 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 thi s 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: CSIR, 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

.5-10

5.3 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 product 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 receivinginsufficient 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, assumptions, and results publicly available, granting advocates, manufacturers, and other interested parties the opportunity to review and comment on this information. The design options considered in the engineering analysis include: using copper die-cast rotor, reducing skew on stack, increasing cross-sectional area of rotor conductor bars, increasing end-ring size, changing the gauge of copper wire in stator, manipulating stator slot dimensions, decreasing air gap between rotor and stator to 12.5 thousandths of an inch, improving grades of electrical steel, using thinner steel laminations, annealing steel laminations, adding stack height, using high efficiency lamination materials, changing run-capacitor ratings, installing better ball bearings and lubricant, and installing a more efficient cooling system.

DOE ’s technical expert, wh o 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 determined 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 develop MSP-efficiency curves for the three representative small electric motors. As discussed 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 IEEE 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 various 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 duel purposes. First, by showing that the output of the software program was in line with the results obtained through testing, the subcontractor’s proprietary software program was validated as a design tool

. DOE feels very confident in its selection of software as it has been used in the past to design, prototype, and produce complete induction motor lines. Second, the designs became the starting point, or baseline models, against which design options were applied to increase efficiency, for each product class analyzed. As new designs were created, careful attention was paid to the critical performance characteristics to ensure that the resulting designs were reasonable and

a Yeadon Energy Systems, Inc. (YES) of Iron Mountain, Michigan.5-11

manufacturable replacements of the baseline motors. To this end, DOE established a set of design limitations that are applied across all six sets of designs.

However, 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 other half follow another less stringent restriction of no more than a 100% increase in stack height. Both restrictions are listed below and the

fo llowing 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 f

ill

– the minimum value of this 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 the total slot area available for winding.)

Air gap between rotor and stator

– the air gap 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 th e “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 polyphase motors there are no NEMA specifications, therefore the designs must maintain the lock ed -rotor torque within 10% of

the baseline model.

Locked-rotor current

–

for single-phase motors, the locked-rotor current should not

ex ceed 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 motors. 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, the5-12

breakdown torque should follow the guidelines established in NEMA MG1-1987 Section

12.37.

Power factor

–

the power factor of the baseline motor should be maintained or increased for all designs.

Speed at rated load

–

the speed of the baseline motor should be maintained or increased for all designs.

Service factor

–

the service factor of each design 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 diameter of the baseline motor should be that of the baseline and remain constant for all designs.

Cooling system

–

the p arameters directly related to the motor’s cooling system, such as ventilation openings in the laminations, should 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 adversely affect motor performance ( e.g. completely removing it) or introduce cusps in the acceleration curve. (Note: this design limitation i s 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 subcontractor 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-tech 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 its5-13

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 pricing scheme developed and discussed in section

5.4 . The results of the test data and the MSP developed from the tear downs of these motors were plotted along with the curves of the theoretical 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 accounting 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 determine the manufacturer selling price (MSP).

Figure 5.4.1. Standard Method of Cost Accounting 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, Emerson Motor Technologies, Regal-Beloit Corporation, and WEG Electric Corporation as well as through conversations with industry experts. Together, the full production cost or manufacturer production cost (MPC) and the non-production costs equal the MSP. Full production cost is a combination of direct labor, direct materials, and

Direct

Labor Direct

Labor Direct

Material Direct

Material Overhead

Overhead Selling Selling General &

Admin. Admin. R & D

R & D Interest

Interest

Indirect Labor Full Production Cost* (Manufacturer Production Cost) Non

- Production Cost

Indirect M aterial

Maintenance

Depreciation

Taxes

Insurance related

to assets Mkt . research

Advertising

POS promotion

Sales person salary + travel

+ commission

Logistics

- Warehousing

- Delivery

- Record keeping

- Order entry/

proces sing Costs of

service &

staff units

General corporate

costs

- comp. etc. Costs

associated

with efforts

to find new or improved products or production

processes Costs

of borrowing

funds

* Tax Reform Act of 1986, essentially, require s companies to measure cost of goods sold as the full production cost of the goods sold. Full Cost of Product Manufacturer Selling Price

Code compliance

Modernization Cust . service5-14

overhead. The overhead contributing to full production cost includes indirect labor, indirectmaterial, maintenance, depreciation, taxes, and insurance related to company assets. Nonproduction costs include the cost of selling (market research, advertising, sales representatives, logistics), 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 section 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 cost 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, ball-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 remain 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 used 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 aluminum 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 bar s 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 discussion below describes 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 th ey apply.

For e xample “end cap assembly” is a heading and under this label there are several itemized parts with associated costs. The BOM includes the following headings, each with an itemized parts list: stator assembly, rotor assembly, end cap assembly, housing assembly, hardware, and final assembly.

As mentioned, each heading has an itemized list of components. The stator assembl y’s itemized lists include prices for cleats, lead wires, capacitor wires (for appropriate motor categories), splices, insulation, slot liner, copper shipping, stator laminations, 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 assembly5-15

list includes paint, a fan shroud, a base, and the actual housing costs. Much of the hardware costs are fixed and include pric es for washers, capacitor covers (when applicable), mounting bolts, cap screws, thermal switch screws, terminal block screws, terminal cover screws, studs, conduit cap, a 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 several 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 underlying 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-year average prices for these commodities, DOE adjusted historical prices to $2008 using the historical 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 prices that domestic producers 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 minimumprices over the time period. The following figures depict the component prices over the fiveyear timeframe.5-16 Figure 5.4.2. Five-Year Copper Wire Prices in $2008 US

Figure 5.4.3. Five-Year Die-Casting Prices in $2008 US5-17 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 production 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 proportion 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 Economic Census of Industry 3 by the U.S. Census Bureau. Several markups were applied successively and with cumulative effect to the base hourly rate to obtain a fully burdened rate which was intended to be representative of the labor costs associated with manufacturing these motors. Table 5.4.1 shows the base labor rate DOE started with, each markup with its corresponding markup percentage and the resulting partially burdened rate after that markup, and a final fully burdened labor rate. The markups were applied in the order they appear in the table and to the “rate per hour” listed 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 rate by 33 percent for indirect production.5-18

Table 5.4.1. Labor Markups for Small Electric Motor Manufacturers

Item description Markup Rate per hour

Labor cost per hour $ 1 3.55

Indirect Production 33 % $ 18.02

Fringe † 28 % $ 2 3.07

Assembly Labor Up

- time † † 43 % $ 32.99

Cost of Labor Input to Spreadsheet $ 32.99

Cost per hour is from U.S. Census Bureau, 2002 Economic Census of Industry, published December 2004, Table 5, page 5

. Data for NAICS code 3353121 “Fractional Horsepower Motors” Production work ers hours and wages. Indirect Production Labor (Production managers, quality control, 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 software 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 learned 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 calculated as a variable labor cost, namely the “Rotor Core Assembly” process

. This activity changed to a longer time when the subcontractor’s designs called for a copper rotor. The reason for 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, and 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 stripping and terminal placement, magnet wire or lead splicing, using the stator test system, and applying the varnish. Adding the fan, machining the shaft, pressing the shaft onto the rotor, balancing 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 hardware section are estimates of adding the components to the motor. Various washers, bolts, studs, screws, grommets for capacitor wire (when applicable), start and/or run capacitors (when applicable), and a start switch (when applicable) are among5-19

these hardware components. Included in the final 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 f acility. 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 with 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 accounts 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, indirect materials and energy use, taxes, insurance, and depreciation. DOE applies factory 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 development, 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 markup gives a manufacturer selling price

MSP.

5.5 RESULTS OF ENGINEERING ANALYSIS

For the polyphase and CSIR motors analyzed, DOE developed eight efficiency levels using a motor design software tool, and for the CSCR motor analyzed DOE developed nine efficiency levels. These included a baseline design, 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 electric motor design created. Throughout this section, DOE shows the bottoms-up derived MSP’s

.

The engineering analysis results are essentiall y six manufacturer selling price-versus-fullload efficiency curves that represent two relationships for each of the three representative product class es 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 was done to determine how the cost-efficiency5-20

relationship would change for space constrained 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 analyz ed . 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 Point5-21

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 analysis 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 theMSP 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 motor, which has a MSP of $1,770.27.

Table 5.5.1. Efficiency and MSP Data for Polyphase Motor

Efficiency Level Eff iciency % (Design 1 / Design 2)* M SP $ (Design 1 / Design 2)*

Baseline 77. 2 % $ 97.74

E L 1 78.7 % $ 103.81

E L 2 80.0 % $ 107.01

E L 3 81.6 % $ 112.88

E L 4 82.5 % $ 117.01

E L 5 85.2 % / 85.2 % $ 229.84 / $ 150.86

E L 6 86.7 % / 86.4 % $ 236.20 / $ 184.73

E L 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.5-22

Table 5.5.2 presents some of the design and performance specifications associated with the eight polyphase designs presented above. Additionally, DOE provides 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 analyzed. The max-tech design incorporates a high-grade non-traditional electromagnetic steel (Hiperco 50 TM ) alloy 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 skewing the Y-axis. For this reason, the engineering analysis results are presented again without the max-tech design in Figure 5.5.4.5-23

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 analysis results in a tabular form, including the full-load efficiency values and the MSPs. Moving from the baseline motor to the max-tech5-24

motor, DOE found tha t 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 Capacitor-Start, Induction-Run, 48-Frame

Motor

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

Baseline 57.7 % $ 91.04

E L 1 59.5 % $ 95.62

E L 2 62 .0 % $ 98.54

E L 3 64.2 % $ 99.78

E L 4 68.5 % / 68.6 % $ 114.57 / $ 107.19

E L 5 71.2 % / 71.2 % $ 118.98 / $ 120.53

E L 6 73 .0 % / 73.1 % $ 182.28 / $ 132.16

E L 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 and performance specifications associated with the eight CSIR efficiency levels presented above. Additionally, DOE provides more details and performance characteristics for CSIR designs in appendix 5A.5-25

Table 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 7 3.0

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

17 35 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

24M 5 6 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

A l 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. (μF) 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-traditional 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 5.5.6.5-26

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

Figure 5.5.6. Capacitor-Start, Capacitor-Run 3⁄4 Horsepower, 4-Pole, 56-Frame Engineering Analysis Curve, without Maximum Technology Point5-27

Table 5.5.5 presents the same engineering analysis 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 motor, which has a MSP of $1,778.48.

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

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

Baseline 71 .0 % $ 110.82

E L 1 74.3 % $ 116.06

E L 2 78.3 % / 78.4 % $ 136.22 / $ 128.60

E L 3 80.3 % / 80.5 % $ 141.49 / $ 133.71

E L 4 81.6 % / 81.8 % $ 145.27 / $ 141.10

E L 5 82.7 % / 82.9 % $ 152.88 / $ 149.23

E L 6 83.7 % / 83.5 % $ 237.53 / $ 156.85

E L 7 85.4 % / 85.6 % $ 245.36 / $ 172.75

E L 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 and performance specifications associated with the nine CSCR efficiency levels presented above. Additionally, DOE provides more design details and performance characteristics for CSCR designs in appendix 5A.5-28

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

Parameter (Units) Baseline EL1 EL2 EL3 EL4 EL5 EL6 EL7 EL8

- 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 Design 1

Design 2 Efficiency (%) 71.0 74.3 78.3

78.4 80.3

80.5 81.6

81.8 82.7

82.9 83.7

83.5 85.4

85.6 87.3

87.3

Power

Factor 68.6 77.1 75.1

8 3.9 80.1

83.4 90.7

96 92.2

95.9 94.6

99.2 93.1

97.5 90.6

99.4 Speed (RPM) 1735 1740 1742

1731 1742

1735 1744

1753 1769

1763 1733

1760 1762

1765 1764

1755 Torque (oz

- ft) 27.4 27.3 27.2

27.3 27.4

27.4 27.2

27.1 27.0

27.0 27.3

27.1 26.9

26.6 26.9

27.1

Curr ent (A) 10.1 8.53 8.30

7.40 7.66

7.29 6.58

6.23 6.40

6.16 6.16

5.92 6.18

5.78 6.17

5.64

Core

Steel 24M56 24M56 24M19

24M56 24M19

24M56 24M19

24M56 24M19

24M56 29M15

24M56 29M15

24M19 Hiperco 50

29M19 Stack Height (in) 3 3.15 3.3

4.1 3.45

4.6 3.6

4.5 3.6

5 3.6

5.5 3.6

4.75 3. 6

6

Rotor Material Al Al Al

Al Al

Al Al

Cu Cu

Cu Al

Cu Cu

Cu Cu

Cu

Main Wire (AWG) 18 20.5 20.5

20.5 20

21.5 20

21.5 20

21.5 20

21.5 20

21.5 20

21.5

Aux. Wire (AWG) 19 21.5 21.5

21.5 21

21 21

21 21

21 19

21 19

21 21.5

21 Start Cap

. (μF) 433 433 433

433 433

433 433

433 433

433 433

433 43 3

433 433

433 Run Cap. (μF) 7.5 20 20

20 25

25 35

35 40

40 40

45 45

45 35

45 LR Torque (oz

- ft) 76.4 77.7 78.0

85.5 81.1

78.3 77.6

75.6 79.0

76.8 71.6

73.8 71.7

76.4 77.2

71.6

LR Current (A) 53.2 53. 1 54.3

47.3 54.3

34.6 52.1

47.1 58.4

44.7 45.2

45.0 47.4

43.9 47.8

42.9

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 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.5-29

5.6 SCALING RELATIONSHIPS

In order to reduce the analytical burden associated with conducting a detailed engineering analysis of the cost-efficiency relationship on all 72 product classes, DOE develop ed 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 class es . 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 manufacturers 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 according 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 relationships between product classes, DOE examined all the publicly available efficiency data for small electric motors covered by this rulemaking. DOE compiled available catalog data and online listings for polyphase, CSIR, and CSCR motors to see how efficiency changes across 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. Th e 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 cons is tent. 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 data to create an accurate assessment of the product line , then that manufacturer’s data was not 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 lists5-30

efficiency in their catalog it was not necessarily calculated and reported in the same way that another manufacturer calculates and 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 purchased and tested a sample product line of polyphase and CSIR motors to verify efficiency relationships. DOE was unable to purchase and test a complete product line of CSCR motors because 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 class es , not necessarily to confirm the value of efficiency listed by the manufacturer. Results of this testing 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 relationship 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 logarithmic 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 complete 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 aggregated results are shown in Figure 5.6.1 and Figure

5.6.2 . The plots show that the data can be graphed linearly, which eases interpretation of trends

in motor losses.5-31 Figure 5.6.1. Manufacturer Motor Losses for Polyphase Motors

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 individual manufacturer data, DOE us ed the equations of the lines of best fit to interpolate and extrapolate 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. Generating 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 different performance characteristics that can ultimately affect the efficiency of the motor. Therefore, DOE estimated what motor losses, and thus efficiency, would be for motors 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 to5-32

correspond to the value of the baseline efficiency 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 the motor losses of the baseline design DOE developed in the engineering analysis for that same 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, thus creating a baseline motor loss level for all polyphase product class es . This constituted 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 utilized separately for polyphase and CSIR motors using product line data for each of those moto r categories. For CSCR motors, however, there was not enough information available to identify efficiency relationships between product classes. This is because manufacturers do not currently make CSCR motors for all of the horsepower and pole configuration combinations that 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 line s. DOE found that the relationships, or changes in efficiency relative to horsepower, appeared to be the same for both motor categories, but the efficiency of CSCR motors was shifted higher. This relationship can be seen in Figure 5.6.3

.

Figu re 5.6.3. Four Pole CSIR Efficiency vs. Four Pole CSCR Efficiency

In light of the parallel efficiency relationship 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 for5-33

CSIR 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 representative product class analyzed for CSCR

motors.5-34 REFERENCES

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 Statistics, 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.