5-i CHAPTER 5: ENGINEERING ANALYSIS

TABLE OF CONTENTS

5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.2 STRUCTURING THE ENGINEERING ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 5.2.1 Scaling Relationships inTransformer Manufacturing . . . . . . . . . . . . . . . . . . . . 5-9 5.3 TECHNICAL DESIGN INPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12 5.3.1 Design Line 1 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17 5.3.2 Design Line 2 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18 5.3.3 Design Line 3 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 5.3.4 Design Line 4 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21 5.3.5 Design Line 5 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22 5.3.6 Design Line 6 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 5.3.7 Design Line 7 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24 5.3.8 Design Line 8 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25 5.3.9 Design Line 9 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 5.3.10 Design Line 10 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27 5.3.11 Design Line 11 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28 5.3.12 Design Line 12 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29 5.3.13 Design Line 13 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30 5.3.14 Summary of Design Line Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31 5.4 MATERIAL AND LABOR INPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-36 5.4.1 Material Inputs to the Desi gn Software - Liquid-Immersed . . . . . . . . . . . . . . 5-37 5.4.2 Material Inputs to the Design Software - Dry-type . . . . . . . . . . . . . . . . . . . . . 5-41 5.4.3 Labor Cost Inputs to the Design Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44 5.5 RESULTS OF THE ANALYSIS ON EACH DESIGN LINE . . . . . . . . . . . . . . . . . . . 5-45 5.6 TWO EXAMPLE TRANSFORMER DESIGNS AND COST BREAKDOWNS . . . 5-59 5.6.1 Results for DL3 Transformer, M6CuAl at $3 A and $1 B . . . . . . . . . . . . . . . . 5-59 5.6.2 Results for DL12 Transformer, M3CuCu at $3A and $1B . . . . . . . . . . . . . . . 5-64

LIST OF TABLES

Table 5.2.1 Product Classes and Number of kVA Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 Table 5.2.2 Engineering Design Lines (DL) and Representative Units for Analysis . . . . . . 5-4 Table 5.2.3 Common Scaling Rela tionships in Transformers . . . . . . . . . . . . . . . . . . . . . . 5-10 Table 5.3.1 A and B Combinations used by Software to Genera te Design Database . . . . . 5-13 Table 5.3.2 Core Steel Grades, Th icknesses and Associated Losses . . . . . . . . . . . . . . . . . 5-15 Table 5.3.3 Core Configurations Used in Each Design Line . . . . . . . . . . . . . . . . . . . . . . . 5-16 Table 5.3.4 Design Option Combinations for the Representative Unit from DL1 . . . . . . . 5-18 Table 5.3.5 Design Option Combinations for the Representative Unit from DL2 . . . . . . . 5-19 Table 5.3.6 Design Option Combinations for the Representative Unit from DL3 . . . . . . . 5-20 Table 5.3.7 Design Option Combinations for the Representative Unit from DL4 . . . . . . . 5-225-ii Table 5.3.8 Design Option Combinations for the Representative Unit from DL5 . . . . . . . 5-23 Table 5.3.9 Design Option Combinations for the Representative Unit from DL6 . . . . . . . 5-24 Table 5.3.10 Design Option Combinations for the Representative Unit from DL7 . . . . . . . 5-25 Table 5.3.11 Design Option Combinations for the Representative Unit from DL8 . . . . . . . 5-26 Table 5.3.12 Design Option Combinations for the Representative Unit from DL9 . . . . . . . 5-27 Table 5.3.13 Design Option Combinations for the Representative Unit from DL10 . . . . . . 5-28 Table 5.3.14 Design Option Combinations for the Representative Unit from DL11 . . . . . . 5-29 Table 5.3.15 Design Option Combinations for the Representative Unit from DL12 . . . . . . 5-30 Table 5.3.16 Design Option Combinations for the Representative Unit from DL13 . . . . . . 5-31 Table 5.3.17 Liquid-Immersed Design Lines and Representative Units . . . . . . . . . . . . . . . 5-32 Table 5.3.18 Dry-Type, Low-Voltage Desi gn Lines and Representative Units . . . . . . . . . . 5-33 Table 5.3.19 Dry-Type, Medium-Voltage , Single-Phase Design Lines . . . . . . . . . . . . . . . . 5-34 Table 5.3.20 Dry-Type, Medium-Volta ge, Three-Phase Design Lines . . . . . . . . . . . . . . . . . 5-35 Table 5.4.1 Variable Material Inputs for Liquid-Immersed Units . . . . . . . . . . . . . . . . . . . 5-38 Table 5.4.2 Variable Tank Sizes for Design Line 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-39 Table 5.4.3 Summary Table of Fixed Mate rial Costs for Liquid-Immersed Units . . . . . . . 5-40 Table 5.4.4 Variable Material Inputs for Dry-Type Units . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41 Table 5.4.5 Summary Table of Fixed Ma terial Costs for Dry-Type Units . . . . . . . . . . . . . 5-43 Table 5.4.6 Labor Markups for Liquid-I mmersed and Dry-Type Manufacturers . . . . . . . . 5-44 Table 5.6.1 Bill of Materials for Ex ample Design from DL3 Database . . . . . . . . . . . . . . . 5-62 Table 5.6.2 Bill of Materials for Ex ample Design from DL12 Database . . . . . . . . . . . . . . 5-66

LIST OF FIGURES
Figure 5.4.1 Standard Method of Cost Accounting for Standards Rulemaking . . . . . . . . . 5-36 Figure 5.5.1 Scatter Plot of Manufacturer Selling Price and Efficiency for DL1 . . . . . . . . 5-46 Figure 5.5.2 Scatter Plot of Manufacturer Selling Price and Efficiency for DL2 . . . . . . . . 5-47 Figure 5.5.3 Scatter Plot of Manufacturer Selling Price and Efficiency for DL3 . . . . . . . . 5-48 Figure 5.5.4 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL4 . . . . . . . 5-49 Figure 5.5.5 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL5 . . . . . . . 5-50 Figure 5.5.6 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL6 . . . . . . . 5-51 Figure 5.5.7 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL7 . . . . . . . 5-52 Figure 5.5.8 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL8 . . . . . . . 5-53 Figure 5.5.9 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL9 . . . . . . . 5-54 Figure 5.5.10 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL10 . . . . . . 5-55 Figure 5.5.11 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL11 . . . . . . 5-56 Figure 5.5.12 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL12 . . . . . . 5-57 Figure 5.5.13 Scatter Plot of Manufacturin g Selling Price and Efficiency for DL13 . . . . . . 5-58 Figure 5.6.1 Cost Breakdown for DL3 M6CuAl Design at $3A, $1B . . . . . . . . . . . . . . . . . 5-63 Figure 5.6.2 Cost Breakdown for DL12, M3CuCu Design at $3A, $1B. . . . . . . . . . . . . . . 5-675-iii LIST OF ACRONYMS AND ABBREVIATIONS A present value of future core losses ($/watt) AL aluminum ANOPR Advance Notice of Proposed Rulemaking ANSI American National Standards Institute B present value of future coil losses ($/watt) BIL basic impulse insulation level CSA Canadian Standards Association CU copper DL design line (followed by a number indicating which design line) DOE United States Department of Energy H-O DR laser-scribed M3 core steel Hz hertz kV kilovolt kVA kilovolt-ampere (transformer size rating) M* M2, M3, M4, M6 - thickness of core steel NEMA National Electrical Manufacturers Association NCI Navigant Consulting, Inc. (formerly Arthur D. Little, Inc.) NL no-load losses NOPR Notice of Proposed Rulemaking OPS Optimized Program Service, Inc. ORNL Oak Ridge National Laboratory PC product class SA1 Metglas amorphous core material SEC Securities and Exchange Commission TL total losses US United States V volts Y wye-type transformer terminal connection ZDMH mechanically scribed, d eep-domain refined core steel 

### M phasea During the first quarter of 2002, meetings were held with eight distribution transformer manufacturers, including ABB Power Technology Products Division USA (both liquid-immersed plant and a dry-type plant), Acme Electric Corporation, Cooper Power Industries, Federal Pacific Transformer Company, Howard Industries Inc., Jefferson Electric Inc., Kuhlman Electric Corporation, and Square-D Company. The Department also met with AK Steel, a core steel manufacturer.

5-1 CHAPTER 5: ENGINEERING ANALYSIS

5.1 INTRODUCTION
This chapter provides the technical support documentation on the engineering analysis, evaluating both liquid-immersed and dry-type distribution transformers. The purpose of the engineering analysis is to estimate the relationship between the manufacturer’s selling price of a transformer and its efficiency level. This relati onship serves as the basis for the subsequent costbenefit calculations for indi vidual consumers, manufacturers, and the nation (see Chapter 8, Life-Cycle Cost and Payback Period Analyses). Determining the cost-efficiency relationship involves analysis of the options available to manufacturers for increasin g the efficiency of a distribution transformer.
The Department selected a modified design-option approach for the engineering analysis. The design-option approach norma lly involves selecting technology and/or material options for transformer designs, and requesting that manufacturers provide estimated costs of transformersbuilt with these options at various efficiency levels. The modification applied to the designoption approach involved using a third party to create the designs for the transformer design database and working w ith manufacturers to sel ect appropriate design options and obtain correct costing information.
In planning the structure of the engineering analysis, the Department visited the facilities of nine distribution transformer manufacturers and one component supplier. aTogether, representatives of these companies contributed more than 60 hours of presentations, technical information, and plant tours to the engineering analysis. Topics discussed at these meetings included the structure of the engineering an alysis, product classifications, product design, materials handling, market dy namics, high-efficiency design s, and manufacturers’ concerns relating to the rulemaking.
The Department recognizes that the results in this chapter are not the definitive answer to the question of the relationship between a manuf acturer’s cost and the efficiency of the transformer. These results assume an ideal situation, where manufacturers do not incur any increased retooling, redesign, marketing or special handling costs associated with changing materials or core/coil dimensi ons. The Department requests th at reviewers, and particularly manufacturers, submit comments on what additional costs they may incur if minimum efficiency standards are introduced. Identification of additional costs will be important in subsequent stages of the rulemaking process (e.g., manufacturer impact analysis (MIA)).5-2 5.2 STRUCTURING THE ENGINEERING ANALYSIS

As discussed in the market and technol ogy assessment (Chapter 3), distribution transformers are classified by their insulation type (liquid-immersed or dry-type), the number of phases (single or three), the primary voltage (low -voltage or medium-volta ge for dry-types) and the basic impulse insulation level (BIL) rating (fo r dry-types). Following this convention, the Department developed ten product classes, shown in Ta ble 5.2.1. These product classes were adapted from National Electrical Manufacturers Association’s (NEMA) TP 1 classification system, though they do not follow the classificati on system precisely. NE MA’s TP 1 classifies medium-voltage, dry-type distribution tr ansformers into tw o product classes, < 60 kilovolt (kV) BIL and >60 kV BIL. Based on input from manufact urers, the Department elected to increase the differentiation of medium -voltage, dry-type tran sformers, and create thr ee product classes of BIL ratings: 20-45 kV BIL, 46-95 kV BIL and > 96kV BIL (see section 3.3).
Within each of these product classes, distribu tion transformers are further classified by their kVA rating. The range and number of kil ovolt-amp (kVA) ratings varies by product class, as shown in Table 5.2.1. For NEMA’s TP 1- 2002, there are 99 kVA ratings across all the product classes (see section 3.7.1). For the De partment, because of the greater degree of differentiation around the BIL rating, there are 115 kVA ratings across a ll the product classes. These kVA ratings are essentially size categories, indicating the power handling capacity of the transformers. Due to the physical principles of construction and material properties, efficiency levels vary by both pr oduct class and kVA rating.
Table 5.2.1 Product Classes and Number of kVA Ratings

Distribution Transformer Product Class kVA Range Number of kVA Ratings 1. Liquid-immersed, medium-voltage, single-phase 10-833 13 2. Liquid-immersed, medium-voltage, three-phase 15-2500 14 3. Dry-type, low-voltage, single-phase 15-333 9 4. Dry-type, low-voltage, three-phase 15-1000 11 5. Dry-type, medium-voltage, single-phase, 20-45 kV BIL 15-833 12 6. Dry-type, medium-voltage, three-phase, 20-45 kV BIL 15-2500 14 7. Dry-type, medium-voltage, single-phase, 46-95 kV BIL 15-833 12 8. Dry-type, medium-voltage, three-phase, 46-95 kV BIL 15-2500 14 9. Dry-type, medium-voltage, single-phase, > 96 kV BIL 75-833 8 10. Dry-type, medium-voltage, three-phase, > 96 kV BIL 225-2500 8
Total 1155-3 The Department recognized that it would be impractical to conduct a detailed engineering analysis of the cost-e fficiency relationship on all 115 kVA ra tings, so it sought to develop an approach that simplified the analysis while retaining reasonable levels of accuracy. The Department consulted w ith industry representatives and tr ansformer design engineers, and developed an understanding of the construction principles for distribution transformers. It found that many of the units share similar designs and construction methods. Thus, the Department simplified the analysis by creating 13 engineerin g design lines, which group together kVA ratings based on similar principles of de sign and construction. These 13 design lines subdivide the product classes, to improve the accuracy of the engineering analysis. These 13 engineering design lines differentiate the transformers by insulation type (liquid-immersed or dry-type), number of phases (one or three), and primary insulation le vels (three different BIL levels for medium voltage dry-types).
The Department then selected one unit from eac h of the engineering design lines for study in the engineering analysis and the LCC analysis (see Chapter 8). It then extrapolated the results of this analysis from the unit studied to the other kVA ratings in that engineering design line. This reduced the number of units for analysis fro m 115 to 13. The technique used to extrapolate the findings is referred to as “the 0.75 scaling rule .” This rule states that, for similarly-designed transformers, costs of c onstruction and losses scale to the ratio of kVA ratings raised to the 0.75 power. The relationship is valid where the optimum efficiency loading points of the two transformers being scaled are the same. An example of how this scaling can be applied appears in section 5.2.1 of this chapter. A technical discussion on the derivation of the 0.75 scaling rule appears in Appendix 5-B.
Table 5.2.2 presents the Department’s 13 de sign lines and the representative units selected from each engineering design line for analysis. Descriptions of each of the design lines and the rationale behind the selection of the represen tative units follow Table 5.2.2.5-4 Table 5.2.2 Engineering Design Lines (DL) and Representative Units for Analysis

PC* DL Type of Distribution Transformer kVA Range Voltage Taps Secondary Voltages Engineering Design Line Representative Unit

1 1 Liquid-immersed,medium-voltage, singlephase, rectangular tank 10-100 ±2-2.5% 240/120 to 600V 50kVA, 65 / C, single-phase, 60Hz, 7200V primary, 240/120V secondary, rectangular tank

2 Liquid-immersed,medium-voltage, singlephase, round tank 10-100 ±2-2.5% 120/240 to 600V 25kVA, 65 / C, single-phase, 60Hz, 24940GrdY/14400V primary, 120/240V secondary, round tank

3 Liquid-immersed,medium-voltage, singlephase 167-833 ±2-2.5% 120/240 to 600V 500kVA, 65 / C, single-phase, 60Hz, 14400/24940YV primary, 277/480YV secondary

2 4 Liquid-immersed,medium-voltage, threephase 15-500 ±2-2.5% 208Y/120 to 600V 150kVA, 65 / C, three-phase, 60Hz, 12470Y/7200V primary, 208Y/120V secondary

5 Liquid-immersed,medium-voltage, threephase 750-2500 ±2-2.5% 208Y/120 to 600Y/347V 1500kVA, 65 / C, three-phase, 60Hz, 24940GrdY/14400V primary, 480Y/277V secondary

3 6 Dry-type, low-voltage, single-phase 15-333 Universal ** 120/240 to 600V 25kVA, 150 / C, single-phase, 60Hz, 480V primary, 120/240V secondary, 10kV BIL

4 7 Dry-type, low-voltage, three-phase 15-150 Universal ** 208Y/120 to 600Y/347V 75kVA, 150 / C, three-phase, 60Hz, 480V primary, 208Y/120V secondary, 10kV BIL

8 Dry-type, low-voltage, three-phase 225-1000 Universal ** 208Y/120 to 600Y/347V 300kVA, 150 / C, three-phase, 60Hz, 480V Delta primary, 208Y/120V secondary, 10kV BIL

6 9 Dry-type, mediumvoltage, three-phase, 20-45kV BIL 15-500 ±2-2.5% 208Y/120 to 600Y/347V 300kVA, 150 / C, three-phase, 60Hz, 4160V primary, 480Y/277V secondary, 45kV BIL

10 Dry-type, mediumvoltage, three-phase, 20-45kV BIL 750-2500 ±2-2.5% 208Y/120 to 600Y/347V 1500kVA, 150 / C, three-phase, 60Hz, 4160V primary, 480Y/277V secondary, 45kV BIL

8 11 Dry-type, mediumvoltage, three-phase, 60-95kV BIL 15-500 ±2-2.5% 208Y/120 to 600Y/347V 300kVA, 150 / C, three-phase, 60Hz, 12470V primary, 480Y/277V secondary, 95kV BIL

12 Dry-type, mediumvoltage, three-phase, 60-95kV BIL 750-2500 ±2-2.5% 208Y/120 to 600Y/347V 1500kVA, 150 / C, three-phase, 60Hz, 12470V primary, 480Y/277V secondary, 95kV BIL

10 13 Dry-type, mediumvoltage, three-phase, 110-150kV BIL 225-2500 ±2-2.5% 208Y/120 to 600Y/347V 2000kVA, 150 / C, three-phase, 60Hz, 12470V primary, 480Y/277V secondary, 125kV BIL * PC means Product Class (see Chapter 3 of the TSD). PC5, PC7 and PC9 are based on their three-phase counterparts. They were not addressed in the detailed engineering analysis because of their low sales volume. ** Universal Taps are two above and four below 2.5 percent Dry-type distribution transformers are br oken into eight engineering design lines, primarily according to their BIL levels. The Department believes this level of disaggregation is necessary to capture important differences in the cost-efficiency relationshi p between units as the5-5 BIL level varies. For example, a 300 kVA, three- phase, dry-type unit can appear in design lines 8, 9, 11, or 13 depending on whether the BIL level is 10 kV, 20-45 kV, 60-95 kV, or 110-150 kV.
For design lines 9 through 13, it should be noted that the representative units selected for some of the dry-type design lin es may not be the standard BIL levels associated with a given primary voltage. The Department selected a slightly higher BIL level for the representative units from these design lines to ensure that any candidate minimum efficiency standard would not excessively penalize customers purchasing higher BIL levels. For example, a 300 kVA with a 4160V primary is called a “5kV cl ass” transformer and would nor mally be built with a 30kV BIL level. However, customers also order a 5kV cl ass 300 kVA with 45kV BIL or 60kV BIL. If the candidate minimum efficiency standard were set at 30kV BIL, it may be prohibitively difficult to achieve that same candi date standard level for customer s ordering 60kV BIL. Thus, the Department elected to evaluate the middle BIL level (in this example, 45kV BIL), making it slightly easier for the lower BIL, and not too difficult for the higher BIL, to achieve compliance.

The remainder of this sec tion discusses the engineering design lines, providing a description and explanation of the transformers covered.
Design Line 1 . This is the basic, high-volume line for rectangular-tank, single-phase, liquid-immersed distribution tran sformers, ranging from 10 kVA to 100 kVA. The BIL level of the windings ranges between 30 kV and 150 kV, and the tap arrangement is four 21⁄2 percent, two above and two below normal. Th e primary voltage is less than 35 kV and the secondary voltage is less than or equal to 600 Volts (V).
The representative unit selected for design lin e 1 is a 50 kVA pad-mounted unit, as this is a high shipment volume rating, a nd is approximately the middle of the kVA range for this design line (10 kVA, 15 kVA, 25 kVA, 37.5 kVA, 50 kVA, 75 kVA and 100 kVA). Also, NEMA recommended a 50 kVA rating for the Department’s analysis. Engineering design and manufacturing differences led to the omission of 167 kVA and higher rated units, which are considered part of design line 3.
Design Line 2 . This is the basic, high-volume lin e for round-tank (pole mounted), singlephase, liquid-immersed distribution transf ormers, ranging from 10 kVA to 100 kVA . Although some manufacturers tend to employ the same basic core/coil desi gn for design line 1 and design line 2, others may have design differences between pad-mounted and pole-mounted transformers. The Department decided to analyze these two types of distribution transforme rs separately for the engineering and Life Cycle Cost (LCC) analysis . The BIL level of the windings ranges between 30 kV and 150 kV, and the tap arrangement is four 21⁄2 percent, two above and two below normal. The primary voltage is less than 35 kV a nd the secondary voltage is less than or equal to 600 V.
The representative unit selected design line 2 is a 25 kVA pole-mounted unit, as this is a high-volume rating for round-tanks, and is approximately in the mi ddle of the kVA range for this5-6 design line (10 kVA, 15 kVA, 25 kVA, 37.5 kVA, 50 kVA, 75 kVA and 100 kVA). Also, NEMA recommended that the Department consider a 25 kVA pole-mounted unit in its analysis. (NEMA, No. 7 at p. 5) Engineering design and manufacturing differences led to the omission of 167 kVA and higher rated units, which ar e considered part of design line 3.
Design Line 3 . This design line groups togeth er single-phase , round-tank, liquidimmersed distribution transformers, ranging fro m 167 kVA to 833 kVA. Together, design lines 1 through 3 cover all the single-phase, liquid-immers ed units (there are no units produced between 100 and 167 kVA). The BIL level of th e windings ranges between 30 kV and 150 kV, and the tap arrangement is four 21⁄2 percent, two above and two below normal. The primary voltage is less than 35kV and the secondary voltage is less than or equal to 600V.
The representative unit selected for design line 3 is a 500 kVA round-tank, as this is a common rating and occurs approximately in the middle of the kVA range for this design line (167 kVA, 250 kVA, 333 kVA, 500 kVA, 667 kVA, and 833 kVA). Although high currents result with 277/480Y Volt secondary at the larg er kVA ratings, high-current bushings are available, and a market does exist for these transformers.
Design Line 4 . Design line 4 represents rectangular tank, three-pha se, liquid-immersed distribution transformers, ranging from 15 kVA to 500 kVA. The BIL level of the windings range between 30 kV and 150 kV, and the tap arra ngement is four 21⁄2 percent, two above and two below normal. The primary vo ltage is less than 35 kV and th e secondary voltage is less than or equal to 600 V.
The representative unit selected for design lin e 4 is a 150 kVA transformer, as this is a common rating and occurs approximately in the mi ddle of the kVA range for this design line (15 kVA, 30 kVA, 45 kVA, 75 kVA, 112.5 kVA, 150 kVA, 225 kVA, 300 kVA, and 500 kVA).
Design Line 5 . Design line 5 represents rectangular tank, three-pha se, liquid-immersed distribution transformers, ranging from 750 kVA to 2500 kVA. Design lines 4 and 5 cover all the three-phase, liquid-immersed units (there are no units produced between 500 and 750 kVA). The BIL level of the windings ranges between 95 kV and 150 kV, and the ta p arrangement is four 21⁄2 percent, two above and two below normal. The primary voltage is less than 35 kV and the secondary voltage is less th an or equal to 600 V.
The representative unit selected for this designline is a 1500 kVA transformer, as this is a common rating in this size range, and occurs in the middle of the kVA range for this design line (750 kVA, 1000 kVA, 1500 kVA, 2000 kVA, and 2500 kVA).
Design Line 6 . Design line 6 represents single-phase, low-voltage, ventilated dry-type distribution transformers, ranging from 15 kVA to 333 kVA. The BIL of the windings is 10 kV, and the tap arrangement is “universal,” mean ing six 21⁄2 percent, two above and four below normal. The Department selected this tap arrangement based on recommendations from5-7 manufacturers who produce transformers at thes e ratings. The primary voltage is 600 V or below. The secondary voltage is less than 600 V.
The representative unit selected for design line 6 is 25 kVA, as this is a common rating in this size range, and occurs toward the low end of the kVA ratings for this design line (15 kVA, 25 kVA, 37.5 kVA, 50 kVA, 75 kVA, 100 kVA, 167 kVA, 250 kVA, 333 kVA).
Design Line 7 . Design line 7 represents three-phase, low-voltage, ventilated dry-type distribution transformers, ranging from 15 k VA to 150 kVA. Because the kVA range of three-phase ratings is broad and construction techniques differ, the Department split the range of three-phase, low-voltage, dry-type transformers into design lin e 7 and design line 8, so the engineering differences in core-coil design a nd manufacturing would be more readily apparent. The primary windings are less than or equal to 600V, with a BIL of 10 kV. The secondary voltage is less than 600 V. The tap arrangemen t is universal, meaning six 21⁄2 percent, two above and four below normal.
The representative unit selected for design line 7 is a 75 kVA transformer, as this is a common rating in this size range, occurs in the middle of the kVA ratings for this design line (15 kVA, 30 kVA, 45 kVA, 75 kVA, 112.5 kVA, 150 kVA), and NEMA recommended this rating for analysis.
Design Line 8 . Design line 8 represents three-phase, low-voltage, ventilated dry-type distribution transformers, ranging from 225 kVA to 1000 kVA. The primary windings are less than or equal to 600V, with a BIL of 10kV. Th e secondary voltage is less than 600V. The tap arrangement is universal, meaning six 21⁄2 pe rcent, two above and four below normal.
The representative unit selected for this designline is a 300 kVA transformer, as this is a common rating in this size range, and occurs toward the low end of the range of kVA ratings included in this design line (225 kVA, 300 kVA, 500 kVA, 750 kVA, and 1000 kVA).
Design Line 9 . Design line 9 represents three-phase, medium-voltage, ventilated drytype distribution transformers, ranging from 15 kVA to 500 kVA. To accommodate the broad kVA range and to allow for engineering differen ces in construction principles and associated costs, the Department split the complete three-phase, medium-voltage, dry-type units into design lines 9 and 10. The primary voltage is less than or equal to 5 kV, and the BIL is between 20 kV and 45 kV. The secondary voltage is less than or equal to 600 V. The tap arrangement is four 21⁄2 percent, two above and two below normal.
The representative unit selected for design lin e 9 is 300 kVA, as this is a common rating in this size range, and occurs near the high end of the kVA ratings for this design line (15 kVA, 30 kVA, 45 kVA, 75 kVA, 112.5 kVA, 150 kVA, 225 kVA, 225 kVA, 300 kVA, and 500 kVA).
Design Line 10 . Design line 10 represents three-phase, medium-voltage, ventilated drytype distribution transformers, ranging from 750 kVA to 2500 kVA. The primary voltage is less5-8 than or equal to 5kV, and the BIL is between 20kV and 45kV. The secondary voltage is less than or equal to 600V. The tap arra ngement is four 21⁄2 percent, tw o above and two below normal.
The representative unit selected for this designline is a 1500 kVA transformer, as this is a common rating, and occurs in the middle of the kVA range for this design line (750kVA, 1000kVA, 1500kVA, 2000kVA, and 2500kVA).
Design Line 11 . Design line 11 represents three-phase, medium-voltage, ventilated drytype distribution transformers, ranging from 15 kVA to 500 kVA. This design line parallels design line 9, with a higher primary insulation level, 60 kV to 95 kV BIL. Because dry-type transformer designs and, more impor tantly, the efficiency of those designs, is strongly influenced by changes in BIL, the Department considered these higher BIL ratings separately. The tap arrangement is four 21⁄2 percent, two above and two below normal. The primary voltage is less than or equal to 15 kV and the secondary voltage is less than or equal to 600 V.
The kVA ratings in design line 11 are 15 kVA, 30 kVA, 45 kVA, 75 kVA, 112.5 kVA, 150 kVA, 225 kVA, 300 kVA and 500 kVA. The ship ments for this design line are concentrated in the 225 kVA through 500 kVA rating; therefore, the Department selected the 300 kVA rating as the representative unit for analysis.
Design Line 12 . Design line 12 represents three-phase, medium-voltage, ventilated drytype distribution transformers, ranging from 750 kVA to 2500 kVA. This design line parallels design line 10, with a higher primary insulation le vel, 60 kV to 95 kV BIL. The tap arrangement is four 21⁄2 percent, 2 above and 2 below normal. The primary volta ge is less than or equal to 15 kV and the secondary voltage is less than or equal to 600 V.
The representative unit selected for this desi gn line is a 1500 kVA transformer, as it is a common rating in this size range and BIL ratin g, and it occurs in the middle of kVA range covered by this design line (750 kVA, 1000 kVA, 1500 kVA, 2000 kVA, and 2500 kVA).
Design Line 13 . As a further extension on the dry-type, three-phase , medium-voltage BIL ranges, the Department analyzed 110 kV to 150 kV BIL, in a design line ranging from 225 kVA to 2500 kVA. The 225 kVA rating is considered to be the lowest kVA rating where one would expect to see a unit with a BIL greater than 110 kV. The tap arrangement is four 21⁄2 percent, two above and two below normal. The primary vo ltage is less than 35 kV and the secondary voltage is less than or equal to 600 V.
This third set of dry-type, three-phase, medium-voltage distribution transformers spans a smaller range of kVA ratings, 225 kVA to 2500 kVA. As most of the sales activity in this design line occurs in the higher kVA ratings, the repres entative unit selected for design line 13 is a 2000 kVA transformer. This unit is a common rating in this size range, occurs toward the high end of the range covered by this design line (225 kVA, 300 kVA, 500 kVA, 750 kVA, 1000 kVA, 1500 kVA, 2000 kVA and 2500 kVA), and NEMA r ecommended this rating for analysis.5-9 In addition to the three product classes for dry-type, medium -voltage, three-phase distribution transformers (for whic h there are five engineering design lines) presented in Table 5.2.1, there are three product classes for single- phase, dry-type, medium -voltage units. As discussed in Chapter 3, the shipment volume for the single-phase, dry-ty pe, medium voltage is very low, and thus it does not warrant the level of effort involve d in conducting analysis on these specific units. The Department decided instead to scale the analysis findings from three-phase units to the single-phase units by dividing by th ree. In this way, the Department was able to concentrate resources and improve the accuracy in other, higher volume and more important distribution transfor mer product classes.

5.2.1 Scaling Relationships in Transformer Manufacturing
As discussed in the previous section, the Department simplified the engineering analysis by creating design lines, selecting representative units from these design lines, and scaling the results of the analysis on these representative units within their respective design lines. This section briefly introduces the scaling relationship the Department used to extrapolate the findings on the representative units to the other kVA ratings.
The scaling formulae are mathematical relationships that exist between the kVA ratings and the physical size, cost, and performance of transformers. The size-versus-performance relationships arise from fundamental equations describing a transformer's voltage and kVA rating. For example, when the kVA rating a nd voltage frequency is fi xed, the product of the conductor current density, core flux density, co re cross-sectional ar ea, and total conductor cross-sectional area is constant.
To illustrate this point, consider a transformer with a fixed frequency, magnetic flux density, current density, and BIL rating. If one enlarges (or decreases) the kVA rating, then the only parameters free to vary are the core cro ss-section and the core window area through which the windings pass. Thus, to increase (or decreas e) the kVA rating, the dimensions for height, width, and depth of the core/coil a ssembly are scaled equally in all directions. Analysis of this scaling relationship reveals that each of the linear dimensions vary as the ratio of kVA ratings to the 1⁄4 power. Similarly, areas vary as the ratios of kVA ratings to the 1⁄2 power and volumes vary as the ratio of the kVA ratings to the 3⁄4 or 0.75 power, hence the term "0.75 scaling rule" (see Appendix 5B). Table 5.2.3 depicts the most co mmon scaling relationshi ps in transformers.5-10 Table 5.2.3 Common Scaling Rela tionships in Transformers Parameter Being Scaled Rela tionship to kVA Rating (varies with ratio of kVA x ) Weight (kVA 1 /kVA 0 ) 3/4

Cost (kVA 1 /kVA 0 ) 3/4 Length (kVA 1 /kVA 0 ) 1/4

Width (kVA 1 /kVA 0 ) 1/4 Height (kVA 1 /kVA 0 ) 1/4

Total Losses (kVA 1 /kVA 0 ) 3/4

No-load Losses (kVA 1 /kVA 0 ) 3/4

The following three relationships are true as the kVA rating increases or decreases, if the type of transformer (distribution or power transformer, liquid-immersed or dry-type, single-phase or three-phase), the primary vo ltage, the core configuration, th e core material, the core flux density, and the current density (amperes per square inch of conduc tor cross-section) in both the primary and secondary winding s are all held constant:
1. The physical proportions are c onstant (same relative shape), 2. The eddy loss proportion is essentially constant, and 3. The insulation space factor (voltage or BIL) is constant.
In practical applications, it is rare to find that all of the above are constant over even limited ranges; however, over a range of one order of magnitude in both directions (e.g., from 50 kVA to 5 kVA or from 50 kVA to 500 kVA), the scaling rules shown in Table 5.2.3 can be used to establish reasonable estimates of performance, dimensions, costs, and losses. In practice, these rules can be applied over even wider ranges to estimate general performance levels.
To illustrate how the scaling laws are used, consider two transformers with kVA ratings of S 0 and S 1 . The no-load losses (NL) and total losses (TL) of these two transformers would be depicted as NL 0 and TL 0 , and NL 1 and TL 1 . Then the relationships between the NL and TL of the two transformers could be shown as follows:

NL 1 = NL 0× (S 1 / S 0 ) 0.75 Eq. 5.1

where:

NL 1 = no-load losses of transformer “1,” NL 0= no-load losses of transformer “0,”5-11 S

1 = kVA rating of transformer “1,” and S

0 = kVA rating of transformer “0.”

and

TL 1 = TL 0× (S 1 / S 0 ) 0.75 Eq. 5.2

where:

TL 1 = total losses of transformer “1,” and TL 0= total losses of transformer “0.”
Equations 5.1 and 5.2 can be manipulated algebr aically to show that the load loss also varies to the 0.75 power. Starting with the con cept that total losses e quals no-load losses plus load losses, we can derive the relationship for load loss (LL), and show that it also scales to the 0.75 power. Specifically:

LL 1 = TL 1 - NL 1 Eq. 5.3

where:

LL 1 = load losses of transformer “1”

Plugging the TL 1 and NL 1 terms into this equation, we find:

LL 1 = (TL 0× (S 1 / S 0 ) 0.75 ) - (NL 0× (S 1 / S 0 ) 0.75 ) Eq. 5.4

LL 1 = (TL 0 - NL 0)× (S 1 / S 0 ) 0.75 Eq. 5.5

LL 1 = (LL 0) × (S 1 / S 0 ) 0.75 Eq. 5.6

Where:

LL 0= load losses of transformer “0.”5-12 Thus, the 0.75 scaling rule can be used to es timate the losses of a tr ansformer, given the losses and kVA rating of a reference unit. However, in order for th is rule to be applicable, the transformer type must be the sa me, and key parameters —such as the type of core material, core flux density, and conductor current density in the high and low voltage windings—must be fixed. For dditional information on the derivation of the 0.75 scaling rule, see Appendix 5B. The Department used the 0.75 scaling rule to scale th e analysis findings on each of the representative units within the 13 design lines. It applied the scaling rule to the design lines in the national impact analysis (Chapter 10), where it scaled lo sses and other properties from the 13 units to the 102 kVA ratings it did not analyze.

5.3 TECHNICAL DESIGN INPUTS
For all the representative units, the engineering analysis explores the relationship between the manufacturing selling prices and corresponding transformer efficiencies. To study this relationship, the Department contracted a transformer design software company called Optimized Program Service, Inc. (OPS) to create a database of designs that span the range of efficiency levels for each of the units being analyzed. The Department learned during its visits to the nine distribution transformer manufacturing facilities in early 2002 that many companies developed and use their own, proprietary de sign software to develop new transformer designs for their customers. The design software creates an optimized, practical transformer design, bill of materials and an electrical analysis report based on a set of input specifications and design parameters. The software produces information about the core and coil design that would enable a manufacturer to build this unit, such as co re dimensions, high- and low-voltage windings, insulation, cooling ducts, and labor . The software generates an estimated cost of manufacturing materials and labor, which is then converted to a sales pr ice by applying markups.
The electrical analysis report estimates the performance of the transformer design (including efficiency) at25 percent, 35 percent, 50 percent, 65 percent, 75 percent, 100 percent, 125 percent, and 150 percent of nameplate load. The software output provides a clear understanding of the relationship between cost and efficiency because it provides deta iled data on design variances, as well as a bill of materials, labor costs, and efficiency. The software does not capture retooling costs associated with changi ng production designs for a specific manufacturer. The Department will research these retoolin g costs in the MIA, following the ANOPR public workshop and when appropriate w ill incorporate these costs in future engineering analyses.
One of the inputs to the design software c onsisted of a range of what are known in the industry as A and B evaluation combinations (see section 3.6, Total Ownership Cost Evaluation). The combination of A and B values supplied to the design software mimics hundreds of distribution transformer purchase orders. The A parameter repres ents a customer's net present value of future losses in the transformer core ( no-load losses) and the B represents a customer's net present value of future losses in the windings (load losses). These values take into account a5-13 range of factors depending on the customer. The B parameter is never larger than A, as this would mean a user was specifying a transforme r whose average load would be more than 100 percent of nameplate load.
The A and B values are expressed in terms of dollars per watt of loss. The greater the values of A and B, the greater the importance a customer attaches to the value of future transformer losses. As A and B values increase, the customer places greater importance on reducing the watts of core and winding losses, and so the cust omer chooses a more efficient transformer.
For the engineering analysis, the Department used broad ranges of A and B evaluation values (presented in Table 5.3.1) resulting in a co mprehensive range of efficiency levels for each design option combination of core steel and wi nding material. During the 2002 site visits, manufacturers helped develop the range of A and B values used in the analysis. These values result in the spectrum of efficiencies represented in transformer orders from customers, as well as a low first-cost design and a maximum technologica lly feasible (“max-tech”) design. For the low first-cost design, the A and B evaluation values are both $0/watt, indica ting that the customer does not attach any financial value to future losses in the core or coil of the transformer being bought. For the maximum technologically feasib le design, the A and B evaluation values are sufficiently high to push the design to the highes t efficiency achievable, and are different for the liquid-immersed and dry-type distribution transformers.
Table 5.3.1 A and B Combinations used by Software to Generate Design Database Transformers A values and increments B val ues and increments Resultant number of (A, B) combinations Liquid-immersed DLs: 1 - 5 $0 to $8 by 0.5 steps $8 to $16 by 1.0 steps* $0 to $3 by 0.25 steps $3 to $6 by 0.5 steps* 179 63* Dry-type DLs: 6 - 13 $0 to $12 by 0.5 steps $0 to $8 by 0.5 steps 289
*Note: The Department conducted extended analyses on the A and B values for the liquid-immersed units when it determined that max tech designs had not been captured with an $8 A and a $3 B. The Department applied the extended analysis only to certain core steels for a repr esentative unit, as manufacturers would not build transformers with certain steels at such high evaluation conditions. As an example of how the software used increments of A and B value combinations, consider design line 1. For one constr uction method of the 50-kVA liquid-immersed transformer, the software woul d be given A values starting at zero and increasing by 50-cent increments and B values starting at zero and increasing by 25-cent increments. Because B is never greater than A, the combinations of ($ A, $B) designs for this design line were ($0.00, $0.00), ($0.50, $0.00), ($0.50, $0.25), ($0.50, $0.50), ($1.00, $0.00), ($1.00, $0.25), ($1.00, $0.50), and so on, totaling 179 different combinations of ($A, $B). The department carried out this evaluation for each core-coil combination cons idered in the analysis. Furthermore, if this core-coil combination studied under an extended analysis (to reach max tech), it would have ($A, $B) designs starting at ($8.00, $3.00) and increasing by $1 increments on the A and 50 cent increments on the B up to $16 and $6, respectively. Thus, the ($A, $B) combinations for those5-14 core-coil combinations to which an extende d analysis was applie d were ($8.00, $3.50), ($8.00, $4.00), ($8.00, $4.50) and so on, for an additional 63 designs.
Occasionally, the design software generated th e same transformer design for two different $A and $B combinations, creating duplicate design s in the engineering analysis database. The Department removed these duplicat e designs from the resultant data base, as they might introduce some bias in the LCC analysis resulting from a greater prevalence of a particular design.
The Department understands that there are many ways to build a transformer, even with constant kVA and voltage ratings. For instance, manufacturers can vary the core steels (e.g., M2, M3, M6), the winding materials (aluminum or copper), and core c onfigurations (shell or core-type). Within each of the design lines discussed in the sections starting at 5.3.1, the Department provides tables listing the design option combinations that it used to analyze each of the representative units. Depending on customer needs, the cost of materials, the capital equipment in their facility, and the skills of their labor force, manufacturers make decisions on how to manufacture a given transformer using di fferent core configurations, core steels and winding materials. To capture this variation in designs, DOE analyzed each representative unit using five to eleven design option combinations of core type, core steel and winding material. As discussed in the technology assessment (see Chap ter 3), core steel is produced in a range of qualities (from an efficiency perspective). M2 co re steel is grain-oriented and has very thin laminations, and cons equently has very low losses. M43 co re steel is not grain-oriented and is rolled in much thicker laminations, thus contributing to higher core losses. Table 5.3.2 lists all the steel types used in the analysis, and properties associated with these steels, including nominal thickness and core losses per pound of steel. Note that the core losses per pound of steel are given as a function of the magnetic flux density, measured in Tesla.5-15 Table 5.3.2 Core Steel Grades, Thic knesses and Associated Losses

Steel Grade Nominal Thickness

(inches) Core Loss at 60 Hz (Watts per Pound at magnetic flux density)* Notes / Remarks

M43 0.0185 2.10 Watts/lb at 1.5 T Non-oriented grain silicon steel M36 0.0185 2.00 Watts/lb at 1.5 T Non-oriented grain silicon steel M19 0.0185 1.65 Watts/lb at 1.5 T Non-oriented grain silicon steel

M6 0.014 0.66 Watts/lb at 1.5 T 0.94 Watts/lb at 1.7 T Grain-oriented silicon steel

M4 0.011 0.51 Watts/lb at 1.5 T 0.74 Watts/lb at 1.7 T Grain-oriented silicon steel

M3 0.009 0.45 Watts/lb at 1.5 T 0.70 Watts/lb at 1.7 T Grain-oriented silicon steel

M2 0.007 0.41 Watts/lb at 1.5 T Grain-oriented silicon steel H0 0.009 0.60 Watts/lb at 1.7 T “High permeability” grade silicon steel

SA1 0.001 0.08 Watts/lb at 1.3 T Amorphous core steel (silicon and boron); flux density limitation - testing at 1.3 T

ZDMH 0.009 0.34 Watts/lb at 1.5 T 0.46 Watts/lb at 1.7 T Imported silicon steel, magnetic domainrefined by mechanical process * Watts of loss per pound of core steel are only comparab le at the same magnetic flux density (measured in Tesla) In addition to selecting a core steel, the ma nufacturer’s selection of a core design may also contribute to the overall efficiency of a transformer. A transformer facility may be optimized to work around one or two core configurations. Table 5.3.3 provi des a list of all the core configurations used for each of the 13 de sign lines. The Department selected these configurations, in combinations w ith the range of core steels and winding materials, to represent the most common construction methods for these k VA ratings in the US market. Note that for design lines 6 and 7, the Department anal yzed two different core configurations.5-16 Table 5.3.3 Core Configurations Used in Each Design Line

Design Line # Phases Core Configuration
DL1 1 Shell-type, wound core - distributed gap
DL2 1 Shell-type, wound core - distributed gap
DL3 1 Shell-type, wound core - distributed gap
DL4 3 Wound core - distributed gap, 5-leg
DL5 3 Wound core - distributed gap, 5-leg
DL6 1 Shell-type and core-type, stacked, butt-lap
DL7 3 Stacked, butt-lap, 3-leg; or Evans wound core- distributed gap
DL8 3 Stacked, butt-lap, 3-leg
DL9 3 Stacked, butt-lap, 3-leg
DL10 3 Stacked, mitered joint, 3-leg
DL11 3 Stacked, mitered joint, 3-leg
DL12 3 Stacked, cruciform, mitered joint, 3-leg
DL13 3 Stacked, cruciform, mitered joint, 3-leg
For the single-phase representative units, the configuration is either core-type or shelltype. This applies whether the core consists of stacked or wound laminations of core steel. For the wound cores, manufacturers generally employ a technique known as ‘distributed gap.’ This means that each lamination of core steel wound ar ound the form will have a start and finish point (the ‘gap’), staggered with respect to the prev ious and the following lamination. The distributed gap is used to minimize the performance impact of the lamination joint gaps (reducing the exciting current) and, by locating inside the coil window, reduces the transformer’s operating sound level.
Three-phase transformers can have three-legged, four-legged, five-legged or Evans cores. Of these, in the engineering analysis, the Department considered the 3-legged, the 5-legged andthe Evans. A three-legged core is assembled from stacked laminations. The joints can be buttlapped or mitered. Where there is an economic need to reduce core losses, particularly in keeping with the use of more efficient grades of core steel (M2 or M3), the mitered core tends to be selected. Also, for larger kVA ratings, design economics may cause the selection of a cruciform core section, consisting of multiple lamination widths in order to create a circular core form around which the windings are placed. By usin g a core configuration that better follows the contours of the windings, losses are again reduced, making a more efficient transformer. The use of the three-legged core usually depends on the primary winding being delta-connected. If the primary winding is wye-connected, as is frequen tly the case for pad-mounted transformers used in underground distribution, the co re configuration needs to be four-legged or five-legged.5-17 The five-legged core is assembled from four wound-core loops, and is the common configuration for liquid-filled three-phase distribution transformers having a wye-wye voltage connection. Again, this occurs for pad-mounted transformers used in underground distribution. The individual core loops have distributed gaps as explai ned for single-phase wound-core transformers.
The Evans core is sometimes employed for small dry-type transformers in the 600V class. It consists of two inner wound cores which link the three winding assemblies. Enveloping these two inner cores is a larger wound core whic h passes through the windows of the two outside windings.
5.3.1 Design Line 1 Re presentative Unit
Design line 1 (DL1) represents rectan gular-tank, liquid-imme rsed, single-phase distribution transformers, ranging from 10 kVA to 100 kVA. The representative unit selected for this design line is a 50kVA pad-mounted unit. The following are the technical specifications which constitute inputparameters to the design software:
KVA: 50 (liquid-immersed, rectangular-tank) Primary: 7200 Volts at 60 Hz Secondary: 240/120V T Rise: 65 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi-Lo Core: Wound core - distributed gap Taps: Four 21⁄2 percent, tw o above and two below normal Impedance Range: 1.5–3.5 percent
For DL1, DOE selected ten construction combinations (called “design option combinations”), based on input from manufacturer s and other technical experts. The core selected was shell-type, because the application is for a pad-mounted unit, and this shape is well suited to a rectangular tank. With the exception of the max tech/high efficiency designs, DOE selected ten design option combinations to repr esent the most common construction practices for this representative unit. It analyzed designoption combinations 2, 8, 9 and 10 with both the normal range of A and B factors and the exte nded A and B factors to capture the maximum technologically feasible efficiency design.5-18 Table 5.3.4 Design Option Combinations fo r the Represen tative Unit from DL1 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type
1 M2 Cu Al Shell
2 * M2 Cu Cu Shell
3 M 3 A l A l S h e l l
4 M 3 C u A l S h e l l
5 M 3 C u C u S h e l l
6 M 6 A l A l S h e l l
7 M 6 C u A l S h e l l
8 *,** SA1 (Amorphous) Cu Cu Core
9 *,*** ZDMH - price 1 Cu Cu Shell
10 *,*** ZDMH - price 2 Cu Cu Shell * Design option combinations 2, 8, 9 and 10 were studied with the extended $A and $B analysis, as these are considered the likely core/co il combinations for high evaluation formulae. This extended analysis means that, in addition to the $0-8A and $0-3B, $8-16A and $3-6B were also analyzed. ** For amorphous metal cores, a magnetic flux density of 13.4 kilogauss and a 0.82 space factor were used. *** ZDMH (mechanically scribed core steel) was analyzed at both a U.S. price and a Mexican/Canadian price, since Mexico and Canada do not apply a 31 percent import duty on ZDMH. See section 3.5.3. The Department analyzed each of the ten design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 2,027 designs (after the removal of any duplicate designs).

5.3.2 Design Line 2 Re presentative Unit
Design line 2 (DL2) represents round-tank, liquid-immersed, single -phase distribution transformers, ranging from 10 kVA to 100 kVA. Th e representative unit selected for this design line is a 25kVA pole-mounted unit. The followi ng are the technical specifications which constitute input parameters to the design software:
KVA: 25 (liquid-imme rsed, round-tank) Primary: 24940GrdY/14400 Volts at 60 Hz (125 kV BIL) Secondary: 120/240V T Rise: 65 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi (Cor e-Type), Lo-Hi-Lo (Shell-Type) Core: Wound core - distributed gap Taps: Four 21⁄2 percent, tw o above and two below normal Impedance Range: 1.0–3.5 percent5-19 For DL2, DOE selected ten design op tion combinations, based on input from manufacturers and other technical experts. The Departmentselected shell-type core configuration because this is commonly used by manufacturers for a 25 kVA transformer. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practices for the representative unit. It analyzed design option combinations 1, 3, 8, 9 and 10 with both the normal range of A and B factors and the extended A and B factors to capture the maximum technologically feasible efficiency design.
Table 5.3.5 Design Option Combinations fo r the Represen tative Unit from DL2 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 * M2 Cu Al Shell
2 M 3 C u A l S h e l l
3 * M3 Cu Cu Shell
4 M 4 A l A l S h e l l
5 M 4 C u A l S h e l l
6 M 6 A l A l S h e l l
7 M 6 C u A l S h e l l
8 *,** SA1 (Amorphous) Cu Cu Core
9 *,*** ZDMH - price 1 Cu Cu Shell
10 *,*** ZDMH - price 2 Cu Cu Shell * Design option combinations 1, 3, 8, 9 and 10 were studied with the extended $A and $B analysis, as these are considered the likely core/co il combinations for high evaluation formulae. This extended analysis means that, in addition to the $0-8A and $0-3B, $8-16A and $3-6B were also analyzed. ** For amorphous metal cores, a magnetic flux density of 13.4 kilogauss and a 0.82 space factor were used. *** ZDMH (mechanically scribed core steel) was analyzed at both a U.S. price and a Mexican/Canadian price, since Mexico and Canada do not apply a 31 percent import duty on ZDMH. See section 3.5.3. The Department analyzed each of the ten design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 2,100 designs (after removal of duplicate designs).

5.3.3 Design Line 3 Re presentative Unit
Design line 3 (DL3) represents round-tank, liquid-immersed, single -phase distribution transformers, ranging from 167 kVA to 833 kVA. The representative unit selected for this design line is a 500kVA round-tank. The followi ng are the technical specifications which constitute input parameters to the design software:
KVA: 500 (liquid-imme rsed, round-tank)5-20 Primary: 14400/24940Y Volts at 60 HZ (150kV BIL) Secondary: 277/480Y Volts T Rise: 65 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi (She ll-Type), Lo-Hi-Lo (Shell-Type) Core: Wound core - distributed gap Taps: Four 21⁄2 percent, tw o above and two below normal Impedance Range: 2.5–5.75 percent
For DL3, the Department selected eight desi gn option combinations of core steel and winding material, based on input from manufactur ers and other technical experts. The core selected was shell-type, because this is commonl y used by industry for this rating. With the exception of the max tech/high-efficiency desi gns, DOE chose design option combinations to represent the most common construction practice for this representative unit. The Department analyzed design option combinations 5, 6, 7 and 8 with both the normal range of A and B factors and the extended A and B factors to capture th e maximum technologically feasible efficiency design.

Table 5.3.6 Design Option Combinations fo r the Represen tative Unit from DL3 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 M6 CU AL Shell
2 M4 AL AL Shell
3 M3 CU AL Shell
4 M2 CU AL Shell

5 * M2 CU CU Shell

6 *,** SA1 (Amorphous) CU CU Shell

7 *,*** ZDMH - price 1 CU CU Shell

8 *,*** ZDMH - price 2 CU CU Shell * Design option combinations 5, 6, 7, and 8 were studied with the extended $A and $B analysis, as these are considered the likely core/co il combinations for high evaluation formulae. This extended analysis means that, in addition to the $0-8A and $0-3B, $8-16A and $3-6B were also analyzed. ** For amorphous metal cores, a magnetic flux density of 13.4 kilogauss and a 0.82 space factor were used. *** ZDMH (mechanically scribed core steel) was analyzed at both a U.S. price and a Mexican/Canadian price, since Mexico and Canada do not apply a 31 percent import duty on ZDMH. See section 3.5.3. The Department analyzed each of the eight design option combinations using the matrix of A and B values described in Table 5.3.1, cr eating 1,674 designs (after removal of duplicate designs)5-21 5.3.4 Design Line 4 Re presentative Unit
Design line 4 (DL4) represents rect angular tank, liquid- immersed, three-phase distribution transformers, ranging from 15 kVA to 500 kVA. The representative unit selected for this design line is a 150kVA transformer. The following are the techni cal specifications that constitute input parameters to the design software:
KVA: 150 (liquid-immersed, pad mount) Primary: 12470Y/7200 Volts at 60 HZ (95kV BIL) Secondary: 208Y/120 Volts T Rise: 65 

### / C Ambient: 20 

### / C Terminal Configuration: ANSI/IEEE C57.12.26, Loop Feed Winding Configuration: Lo-Hi or Lo-Hi-Lo Core: Wound core - distributed gap, 5-leg Taps: Four 21⁄2 percent, tw o above and two below normal Impedance Range: 2.5–3.0 percent
For DL4, DOE selected nine design option comb inations of core steel and winding types based on input from manufacturers a nd other technical experts. With the exception of the max tech/high efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit. It analyzed the design option combinations 3, 6, 7, 8 and 9 with both the norma l range of A and B factors and the extended A and B factors to capture the maximum technologically feasible efficiency design.5-22 Table 5.3.7 Design Option Combinations fo r the Represen tative Unit from DL4 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type 1 M6 AL AL 5-Leg Core 2 M4 AL AL 5-Leg Core
3 * M3 CU AL 5-Leg Core

4 M 3 C U C U 5

- L e g C o r e
5 M 2 C U A L 5

- L e g C o r e
6 * M2 CU CU 5-Leg Core

7 *,** SA1 (Amorphous) CU CU 5-Leg Core
8 *,*** ZDMH-price 1 CU CU 5-Leg Core
9 *,*** ZDMH-price 2 CU CU 5-Leg Core * Design option combinations 3, 6, 7, 8, and 9 were studied with the extended $A and $B analysis, as these are considered the likely core/co il combinations for high evaluation formulae. This extended analysis means that, in addition to the $0-8A and $0-3B, $8-16A and $3-6B were also analyzed. ** For amorphous metal cores, a magnetic flux density of 13.4 kilogauss and a 0.82 space factor were used. *** ZDMH (mechanically scribed core steel) was analyzed at both a U.S. price and a Mexican/Canadian price, since Mexico and Canada do not apply a 31 percent import duty on ZDMH. See section 3.5.3. The Department analyzed each of the nine design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 1,906 designs (after removal of duplicate designs).

5.3.5 Design Line 5 Re presentative Unit
Design line 5 (DL5) represents rect angular tank, liquid- immersed, three-phase distribution transformers, ranging from 750 kVA to 2500 kVA. The representative unit selected for this design line is a 1500kVA transformer. Th e following are the techni cal specifications that constitute input parameters to the design software:
KVA: 1500 (liquid-immersed, pad mount) Primary: 24940GrdY/14400 Volts (125kV BIL) Secondary: 480Y/277 Volts T Rise: 65 

### / C Ambient: 20 

### / C Terminal Configuration: ANSI/IEEE C57.12.26, Loop Feed Winding Configuration: Lo-Hi Core: Wound core - distributed gap, 5-leg Taps: Four 21⁄2 percent, tw o above and two below normal Impedance Range: 5.75 percent5-23 For DL5, the Department selected eight desi gn option combinations of core steel and winding material, based on inputfrom manufacturers and other t echnical experts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practices for the representative unit. It analyzed design option combinations 4, 5, 6, 7, and 8 with both the normal range of A and B factors and the extended A and B factors to capture the maximum technologically feasible efficiency design.
Table 5.3.8 Design Option Combinations fo r the Represen tative Unit from DL5 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type 1 M4 AL AL 5-Leg Core 2 M4 CU AL 5-Leg Core 3 M3 AL AL 5-Leg Core

4 * M3 CU AL 5-Leg Core

5 * M2 CU AL 5-Leg Core
6 *,** SA1 (Amorphous) CU CU 5-Leg Core

7 *,*** ZDMH - price 1 CU CU 5-Leg Core
8 *,*** ZDMH - price 2 CU CU 5-Leg Core * Design option combinations 4, 5, 6, 7, and 8 were studied with the extended $A and $B analysis, as these are considered the likely core/co il combinations for high evaluation formulae. This extended analysis means that, in addition to the $0-8A and $0-3B, $8-16A and $3-6B were also analyzed. ** For amorphous metal cores, a magnetic flux density of 13.4 kilogauss and a 0.82 space factor were used. *** ZDMH (mechanically scribed core steel) was analyzed at both a U.S. price and a Mexican/Canadian price, since Mexico and Canada do not apply a 31 percent import duty on ZDMH. See section 3.5.3. The Department analyzed each of the eight design option combinations using the matrix of A and B values described in Table 5.3.1, cr eating 1,742 designs (after removal of duplicate designs).
5.3.6 Design Line 6 Re presentative Unit
Design line 6 (DL6) represents ventilated dry-type, single-phase, low-voltage distribution transformers, ranging from 15 kVA to 333 kVA. Th e representative unit selected for this design line is a 25 kVA transformer. The following are the technical specificati ons that constitute input parameters to the design software:
KVA: 25 (dry-type) Phases: Single Primary: 480 Volts at 60 Hz (10 kV BIL) Secondary: 120/240 Volts5-24 T Rise: 150 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi (For Core -Type) Lo-Lo-Hi (For Shell-Type) Core: Stacked, butt-lap Taps: Six 21⁄2 percent, two a bove and four below normal Impedance Range: 3.0–6.0 percent
For DL6, DOE selected ten design option combinations of core steel and winding material, based on input from manuf acturers and other technical ex perts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit.
Table 5.3.9 Design Option Combinations fo r the Represen tative Unit from DL6 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 M43, 26 gauge AL (wire) AL (wire) Core 2 M36, 26 gauge AL (wire) AL (wire) Core 3 M19, 26 gauge AL (wire) AL (wire) Core 4 M6 AL (wire) AL (wire) Core 5 M3 CU (wire) AL (strip) Core 6 H-O DR CU (wire) CU (strip) Core 7 M6 AL (wire) AL (wire) Shell 8 M19 AL (wire) AL (wire) Shell 9 M3 CU (wire) AL (strip) Shell 10 H-O DR* CU (wire) CU (strip) Shell * H-O DR is laser-scribed core steel, and represents the max tech for dry-type units. The Department analyzed each of the ten design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 2,597 designs (after removal of duplicate designs).

5.3.7 Design Line 7 Re presentative Unit
Design line 7 (DL7) represents ventilated dry-type, three-phase, low-voltage distribution transformers, ranging from 15 kVA to 150 kVA. Th e representative unit selected for this design line is a 75 kVA transformer. The following are the technical specificati ons that constitute input parameters to the design software:
KVA: 75 (dry-type)5-25 Phases: Three Primary: 480 Volts at 60 Hz (10 kV BIL) Secondary: 208Y/120 Volts T Rise: 150 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi Core: Stacked, butt-lap; Evans Wound, DG Taps: Six 21⁄2 percent, two a bove and four below normal Impedance Range: 3.0–6.0 percent
For DL7, DOE selected seven design option combinations of core steel and winding material, based on input from manuf acturers and other technical ex perts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit.
Table 5.3.10 Design Option Combinations fo r the Represen tative Unit from DL7 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 M19, 26 gauge AL (wire) AL (wire) 3 - Leg Stacked 2 M36, 26 gauge AL (wire) AL (wire) 3 - Leg Stacked 3 M43, 26 gauge AL (wire) AL (wire) 3 - Leg Stacked 4 M6 AL (wire) AL (wire) 3 - Leg Stacked 5 M6 AL (wire) AL (wire) 3 - Leg Evans 6 M3 CU (wire) AL (strip) 3 - Leg Evans 7 H-O DR* CU (wire) CU (strip) 3 - Leg Evans * H-O DR is laser-scribed core steel, and represents the max tech for dry-type units. The Department analyzed each of the seven design option combinations using the matrix of A and B values described in Table 5.3.1, cr eating 1,874 designs (after removal of duplicate designs).

5.3.8 Design Line 8 Re presentative Unit
Design line 8 (DL8) represents ventilated dry-type, three-phase, low-voltage distribution transformers, ranging from 225 kVA to 1000 kVA. The representative unit selected for this design line is a 300 kVA transformer. The following are the techni cal specifications that constitute input parameters to the design software:
KVA: 300 (dry-type) Phases: Three5-26 Primary: 480V at 60 Hz (10 kV BIL) Delta Connected Secondary: 208Y/120 Volts T Rise: 150 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi Core: Stacked, butt-lap Taps: Four 21⁄2 percent, two above and two below normal Impedance Range: 3.0–6.0 percent
For DL8, the Department selected five desi gn option combinations of core steel and winding material, based on inputfrom manufacturers and other t echnical experts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit.
Table 5.3.11 Design Option Combinations fo r the Represen tative Unit from DL8 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 M19, 26 gauge AL (wire) AL (wire) 3 - Leg Stacked 2 M6, 29 gauge AL (wire) AL (strip) 3 - Leg Stacked 3 M6, 29 gauge CU (wire) CU (strip) 3 - Leg Stacked 4 M3 CU (wire) AL (strip) 3 - Leg Stacked 5 H-O DR* CU (wire) CU (strip) 3 - Leg Stacked * H-O DR is laser-scribed core steel, and represents the max tech for dry-type units. The Department analyzed each of the five design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 1,393 designs (after removal of duplicate designs).
5.3.9 Design Line 9 Re presentative Unit
Design line 9 (DL9) represents ventilated dry-type, three-phase, medium-voltage distribution transformers with a 20–45kV BIL, ranging from 15 kVA to 500 kVA. The representative unit selected for this design line is a 300 kVA transformer. The following are the technical specifications that constitute input paramete rs to the design software:
KVA: 300 (dry-type) Phases: Three Primary: 4160V at 60 Hz (45 kV BIL) Delta Connected Secondary: 480Y/277 Volts T Rise: 150 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi5-27 Core: Stacked, butt-lap Taps: Four 21⁄2 percent, two above and two below normal Impedance Range: 3.0–6.0 percent
For DL9, the Department selected six designoption combinations of core steel and winding material, based on inputfrom manufacturers and other t echnical experts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit.
Table 5.3.12 Design Option Combinations fo r the Represen tative Unit from DL9 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type
1 M36, 26 gauge AL (wire) AL (wire) 3 - Leg Stacked 2 M19, 26 gauge AL (wire) AL (wire) 3 - Leg Stacked 3 M6, 29 gauge AL (wire) AL (wire) 3 - Leg Stacked 4 M6, 29 gauge CU (wire) CU (wire) 3 - Leg Stacked 5 M3 CU (wire) AL (strip) 3 - Leg Stacked 6 H-O DR* CU (wire) CU (strip) 3 - Leg Stacked * H-O DR is laser-scribed core steel, and represents the max tech for dry-type units. The Department analyzed each of the six design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 1,620 designs (after removal of duplicate designs).

5.3.10 Design Line 10 Re presentative Unit
Design line 10 (DL10) represents dry-type , three-phase, medium- voltage distribution transformers with a 20–45kV BIL, ranging from 750 kVA to 2500 kVA. The representative unit selected for this design line is a 1500 kVA tr ansformer. The following are the technical specifications that constitute input parameters to the design software:
KVA: 1500 (dry-type) Phases: Three Primary: 4160V at 60 Hz (45 kV BIL) Secondary: 480Y/277 Volts T Rise: 150 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi Core: Stacked, Mitered Taps: Four 21⁄2 percent, two above and two below normal Impedance Range: 5.7 percent5-28 For DL10, the Department selected five desi gn option combinations of core steel and winding material, based on inputfrom manufacturers and other t echnical experts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit.
Table 5.3.13 Design Option Combinations fo r the Represen tative Unit from DL10 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 M6 AL (wire) AL (strip) Stacked 2 M6 CU (wire) CU (strip) Stacked 3 M4 CU (wire) AL (strip) Stacked 4 M3 CU (wire) CU (strip) Stacked 5 H-O DR* CU (wire) CU (strip) Stacked * H-O DR is laser-scribed core steel, and represents the max tech for dry-type units. The Department analyzed each of the five design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 1,400 designs (after removal of duplicate designs).

5.3.11 Design Line 11 Re presentative Unit
Design line 11 (DL11) represents dry-type , three-phase, medium- voltage distribution transformers with a 46–95kV BIL, ranging from 15 kVA to 500 kVA. The representative unit selected for this design line is a 300 kVA tr ansformer. The following are the technical specifications that constitute input parameters to the design software:
KVA: 300 (dry-type) Phases: Three Primary: 12470 Volts at 60 Hz (95 kV BIL) Secondary: 480Y/277 Volts T Rise: 150 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi Core: Stacked, mitered joint Taps: Four 21⁄2 percent, two above and two below normal Impedance Range: 5.0–7.0 percent
For DL11, the Department selected five desi gn option combinations of core steel and winding material, based on inputfrom manufacturers and other t echnical experts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit.5-29 Table 5.3.14 Design Option Combinations fo r the Represen tative Unit from DL11 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 M6 AL (wire) AL (strip) Stacked 2 M6 CU (wire) CU (strip) Stacked 3 M4 CU (wire) AL (strip) Stacked 4 M3 CU (wire) CU (strip) Stacked 5 H-O DR* CU (wire) CU (strip) Stacked * H-O DR is laser-scribed core steel, and represents the max tech for dry-type units. The Department analyzed each of the five design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 1,375 designs (after removal of duplicate designs).

5.3.12 Design Line 12 Re presentative Unit
Design line 12 (DL12) represents dry-type , three-phase, medium- voltage distribution transformers with a 46–95kV BIL, ranging from 750 kVA to 2500 kVA. The representative unit selected for this design line is a 1500 kVA tr ansformer. The following are the technical specifications that constitute input parameters to the design software:
KVA: 1500 (dry-type) Phases: Three Primary: 12470 Volts at 60 Hz (95 kV BIL) Secondary: 480Y/277 Volts T Rise: 150 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi Core: Stacked, cruciform, mitered joint Taps: Four 21⁄2 percent, two above and two below normal Impedance Range: 5.0–8.0 percent
For DL12, the Department selected five desi gn option combinations of core steel and winding material, based on inputfrom manufacturers and other t echnical experts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit.5-30 Table 5.3.15 Design Option Combinations fo r the Represen tative Unit from DL12 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 M6 AL (wire) AL (strip) Stacked 2 M6 CU (wire) CU (strip) Stacked 3 M4 CU (wire) AL (strip) Stacked 4 M3 CU (wire) CU (strip) Stacked 5 H-O DR* CU (wire) CU (strip) Stacked * H-O DR is laser-scribed core steel, and represents the max tech for dry-type units. The Department analyzed each of the five design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 1,344 designs (after removal of duplicate designs).

5.3.13 Design Line 13 Re presentative Unit
Design line 13 (DL13) represents dry-type , three-phase, medium- voltage distribution transformers with a 

### $ 96kV BIL, ranging from 225 kVA to 2500 kVA. The representative unit selected for this design line is a 2000 kVA tr ansformer. The following are the technical specifications that constitute input parameters to the design software:
KVA: 2000 (dry-type) Phases: Three Primary: 12470 Volts at 60 Hz (125 kV BIL) Secondary: 480Y/277 Volts T Rise: 150 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi Core: Stacked, Cruciform, mitered joint Taps: Four 21⁄2 percent, two above and two below normal Impedance Range: 5.0–8.0 percent
For DL13, the Department selected five desi gn option combinations of core steel and winding material, based on inputfrom manufacturers and other t echnical experts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to represent the most common construction practice for the representative unit.5-31 Table 5.3.16 Design Option Combinations fo r the Represen tative Unit from DL13 Design Option Combination Core Material High Voltage Conductor Low Voltage Conductor Core Design Type

1 M6 AL (wire) AL (strip) Stacked 2 M6 CU (wire) CU (strip) Stacked 3 M4 CU (wire) AL (strip) Stacked 4 M3 CU (wire) CU (strip) Stacked 5 H-O DR* CU (wire) CU (strip) Stacked * H-O DR is laser-scribed core steel, and represents the max tech for dry-type units. The Department analyzed each of the five design option combinations using the matrix of A and B values described in Table 5.3.1, crea ting 1,335 designs (after removal of duplicate designs).

5.3.14 Summary of Design Line Coverage
The following four tables summarize the covera ge of each of the design lines in relation to the various product classes and kVA ratings. The abbreviation DL stands for design line, and the row in the table where the phrase “Rep Unit” appears indicates the kVA rating of the representative unit from that design line. For example, DL1 stands for design line 1, spanning from 10 to 100kVA liquid-type, single-phase. The label “Rep Unit” appears in row 50kVA, indicating that the 50kVA is the representative unit for DL1. Similarly, the representative unit for DL2 is the 25kVA unit.5-32 

### kVa Rectan g . Tank Round Tank kVa Desi g n Lines 10 15 15 30 25 45 37.5 75

50 112.5 75 150 100 225 167 300 250 500 333 750 500 1000 667 1500 833 2000 2500 Single-Phase Three-Phase Product Class 1 Product Class 2 Liquid-Immersed, Liquid-Immersed,DL 1DL 2DL 3 Rep Unit Rep Unit

Rep UnitDL 4 Rep UnitDL 5 Rep UnitAs Table 5.3.17 shows, both design line 1 and design line 2 span the single-phase liquidimmersed units from 10 kVA to 100 kVA.
Table 5.3.17 Liquid-Immersed Design Lines and Representative Units5-33 

### kVa Design Lines kVa Design Lines 15 15 25 30 37.5 45

50 75 75 112.5 100 150 167 225 250 300 333 500 750 1000 Single-Phase Three-Phase Product Class 3 Product Class 4 Dry-Type, Low-Voltage Dry-Type, Low-VoltageDL6 Rep UnitDL 7 Rep UnitDL 8 Rep Unit Table 5.3.18 presents the low-voltage, dry-type desi gn lines and the product classes they cover. For single-phase units, one design line spans all nine kVA ratings while, for the three-phase units, two design lines cover the 11 kVA ratings in that product class. There is no overlap of design lines for these two product classes.
Table 5.3.18 Dry-Type, Low-Voltage Design Lines and Representative Units5-34 

### kVa PC 5* Low BIL 20-45 kV PC 7 Med BIL 46-95 kV PC 9 High BIL

>

96 kV 10

- 25

- 37.5

-

50

- 75 100 167 250 333 500 667 833 Dry-Type, Medium-Voltage, Single-PhaseDL 9 / 3DL 11 / 3

Virtual RUDL 13 / 3DL 10 / 3DL 12 / 3 Virtual RU Virtual RU

Virtual RU Virtual RU Table 5.3.19 presents product classes (abbreviated “PC” in this table) for mediumvoltage, single-phase, dr y-type units. As discussed in section 3.4, National Sh ipment Estimate, these units have an extremely low shipment vol ume. All three product classes shown in Table 5.3.18 together represent less than one-third of one percent of dry-type shipments on both a perunit and an MVA-capacity basis. Thus, the De partment did not cons ider it appropriate to conduct three design lines of analysis for each of the BIL ratings shown.
As an alternative to investing time and resources analyzing these low-volume units, the Department used the results from the medium vo ltage three-phase dry-ty pe units (presented in Table 5.3.19) and divided those findings by three, creating virtual (calculated) representative units (labeled as “Virtual RU” in the table) fo r these three product classes. The Department used the representative units from design lines 9, 10, 11, 12 and 13. These virtual representative units are shown in their respective rows, following the a pplication of the quotient. For example, in the single phase (20–45kV BIL) column, the repres entative unit from DL9 is a three-phase 300 kVA unit, so it scales to a single-phase, 100 kVA unit in Table 5.3.19.

Table 5.3.19 Dry-Type, Medium-Voltage , Single-Phase Design Lines

*PC is an abbreviation for Product Class5-35 

### kVa PC 6 Low BIL 20-45 kV PC 8 Med BIL 46-95 kV PC 10 Hi g h BIL

> 96 kV 15

- 30

- 45

- 75

- 112.5

-

150

- 225 300 500 750 1000 1500 2000 2500 Dry-Type, Medium-Voltage, Three-PhaseDL 9DL 11

Rep UnitDL 13DL 10DL 12 Rep Unit Rep Unit

Rep Unit Rep Unit Table 5.3.20 presents the product cl asses (abbreviated “P C” in this table) for the mediumvoltage, three-phase, dry-type distribution tran sformers and each of the design lines and respective representative units. For the higher volume and larger range of kVA ratings, the Department used two separate design lines for each, to maintain accuracy. However, for the very high BIL levels ( 

### $ 96kV BIL), one design line (DL13) covers all the ratings from 225kVA to 2500kVA. As stated earlier, it is extremely unlikel y that a three-phase, dr y-type transformer with a BIL 

### $ 96kV and a power rating less than 150kVA would be built.
Table 5.3.20 Dry-Type, Medium-Voltage, Three-Phase Design Lines5-36 Direct Labor Direct Labor Direct Material Direct Material Overhead Overhead Selling Selling General & Admin. General &

Admin. R & D R & D Interest Interest

Indirect Labor Full Production Cost 1 Non-Production Cost

Indirect Material
Maintenance Depreciation
Taxes
Insurance related to assets Mkt. research Advertising POS promotion

Sales person salary + travel + commission Logistics - Warehousing - Delivery - Record keeping - Order entry/ processing 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

1 Tax Reform Act of 1986, essentially, requires companies to measure cost of goods sold as the full production cost of the goods sold. Full Cost of Product Full Cost of Product

Code compliance Modernization Cust. service

Figure 5.4.1 Standard Method of Cost Accounting for Standards Rulemaking 5.4 MATERIAL AND LABOR INPUTS
The Department uses a standard method of cost accounting to determine the costs associated with manufacturing. This me thodology is illustrated in Figure 5.4.1, where production costs and non-production co sts are combined to determine the full cost of a product.

The Department developed es timates of the costs listed in Figure 5.4.1 from the U.S. Industry Census Data Reports for 1992 and 1997, manufacturer interviews, and SEC 10-K reports for ACME Electric Corporation, Powell Industries, Inc., Magn etek, Inc., and Hammond Manufacturing Company Limited. Together, the full production cost and the non-production cost equal the full cost of the product. Full production cost is a comb ination of direct labor, direct materials, and overhead. The overhead contri buting to full production cost includes indirect labor, indirect material, mainte nance, depreciation, taxes, and insurance related to company assets. Non-production cost includes the cost of selling (market research, advertising, sales representatives, logistics), general and administrative costs, research and development, interest payments and profit f actor (not shown).
For the purposes of the rulemaking, the Department estimated manufacturer internal markups from U.S. Industry Census Data fo r 1992 and 1997; and SEC 10- K reports for Acme, Powell, Magnetek and Hammond. The Department then vette d these estimated markups with5-37 manufacturers during a series of consultative meetings held in early 2002. The following markups resulted:
• Scrap factor: 2.5 percent markup. This mar kup applies to variable materials (e.g., core steel, windings, insulation). It accounts fo r the handling of material (loading into assembly or winding equipment) and the sc rap material that cannot be used in the production of a finished transf ormer (e.g., lengths of wire too short to wind, trimmed core steel). • Factory overhead: 12.5 percent markup. Factory overhead includes all the indirect costs associated with production, indir ect materials and energy use, taxes, and insurance. The Department only applies fact ory overhead to the directmaterial production costs. • Non-production: 25 percent markup. This markup reflects costs including sales and general administrative, R&D, interest payments, and profit fact or. The Department applies the non-production markup to the sum of the directmaterial production, the direct labor, and the factory overhead.
The following example shows how the Departme nt applied the markups to the materials, and how it determined the to tal production cost. Consider a 300kVA 45kV BIL three-phase drytype transformer designed for a $1.50 A and a $0.50 B. This design has $2,902 of materials, including M6 core steel, copper primary and secondary windings, and all the transformer hardware. There are approxima tely 12.5 hours of labor involved in manufacturing this design, resulting in a labor cost of $532. The factory overhead on this design is $362, as it is only applied to the material cost (i.e., 12.5 percent of $2902). The non-production cost is $949, as the 25 percent is applied to the material, labor, and factory overhead costs (i.e., 25 percent of $2902 + $532 + $362). Thus, in total, DOE estimates th is 300kVA three-phase tr ansformer to have a manufacturer selling price of $4,747.
5.4.1 Material Inputs to the Design Software - Liquid-Immersed
In addition to the design pa rameters described in section 5.3, the other critical inputs to the design software are material costs. As the price of one material increases or decreases relative to the other materials, the design software will adjust the design to increase or decrease the content of that material. The design software uses the final marked-up cost of materials as input to the optimization process. In other words, rather than use the raw material cost of $1.00 per pound of core steel, the software uses $1.44 per pound, to reflect a sm all handling and scrap factor (2.5 percent), the factory overhead (12.5 percent), and the non-production markup (25 percent). During its manufacturer site visits in early 2002, the De partment found th is approach to be consistent with that of several manufacturers who operate their ow n, proprietary design software.
The following pages describe all the material prices entered into the design software for liquid-immersed distribution transformers. As shown in these tables, the Department marked up the material prices before entering them into the design software.5-38 Table 5.4.1 Variable Material Inputs for Liquid-Immersed Units
Item and DescriptionMaterialCost*Scrap andHandling**FactoryOverhead***Nonproduction****Input to designsoftware

M2 core steel $1.05 1.025 1.125 1.25 $1.51 M3 core steel $0.95 1.025 1.125 1.25 $1.37 M4 core steel $0.85 1.025 1.125 1.25 $1.23 M6 core steel $0.80 1.025 1.125 1.25 $1.15 ZDMH (mechanically-scribed core steel), non-US price $1.40 1.025 1.125 1.25 $2.02

ZDMH (mechanically-scribed core steel), US price with import tariff $1.83 1.025 1.125 1.25 $2.64

SA1 (amorphous material) - finished core, priced at volume production $1.70 1.1 1.125 1.25 $2.62

Copper wire, formvar, round #10-20 (DL1,2,4) $1.30 1.025 1.125 1.25 $1.87 Copper wire, enameled, round #7- 10 flattened (DL3,5) $1.30 1.025 1.125 1.25 $1.87 Copper wire, enameled, rectan gular sizes (DL3) $1.50 1.025 1.125 1.25 $2.16 Aluminum wire, formvar, round #9-17 (DL1,2,4) $1.36 1.025 1.125 1.25 $1.96 Aluminum wire, formvar, round #7-10 (DL3,5) $1.36 1.025 1.125 1.25 $1.96 Copper strip, thickness range 0.02-0.045 (DL1,2,4) $2.40 1.025 1.125 1.25 $3.46 Copper strip, thickness range 0.030-0.060 (DL3,5) $2.40 1.025 1.125 1.25 $3.46 Aluminum strip, thickness range 0.02-0.045 (DL1,2,4) $1.30 1.025 1.125 1.25 $1.87 Aluminum strip, thickness range 0.045-0.080 (DL3,5) $1.30 1.025 1.125 1.25 $1.87 Kraft insulating paper with diamond adhesive $1.54 1.025 1.125 1.25 $2.22 Mineral oil $1.52 1.025 1.125 1.25 $2.19 * Purchasing price to manufacturers from suppliers of raw materials necessary for building a transformer. Source: Paul Goethe, OPS, 2001; Manufacturer interviews, 2002. ** Handling and scrap is a multiplier factor that applies to variable materials (e.g., core steel, windings, insulation). It accounts for the handling of material (loading into asse mbly or winding equipment) and the scrap material that cannot be used in the production of a finished transformer (e.g., lengths of wire too short to wind, trimmed core steel). Source: Paul Goethe, OPS; Manufacturer interviews, 2002. *** Factory overhead includes all indirect costs associated with production, energy use (e.g., furn ace), light bulbs, insurance on factory and equipment, etc. Source: US Industry Census Data for 1992 and 1997; SEC 10-K reports for Acme, Powell, Magnetek and Hammond; Manufacturer interviews, 2002. **** Material markup reflects non-production costs, including sales and general administrative, R&D, interest payments, and profit factor markups. Source: US Industry Census Data for 1992 and 1997; SEC 10-K reports for Acme, Powell, Magnetek and Hammond; Manufacturer interviews, 2002.5-39 The Department obtained prices of all core steels used in the analysis for a standard quantity order from a major U.S. core steel manufacturer. Due to a U.S. policy to apply an import tariff to core steels from Japan and Italy, the Department considered a dual-price point for a special Japanese core steel called ‘ZDMH’ in this analysis, to understand how significant changes in the cost of core steel may impact the rulemaking process. Given a recentadministrative decision to remove steel import tariffs, DOE will review the need for this dualprice point in the Notice of Proposed Rulemaking (NOPR) analysis.
ZDMH is a mechanically-scribed core steel that has beneficial low-loss properties that can survive the high-tempera ture stress-relief annealing process conducted on wound cores during manufacture. However, this high-effici ency technology option is only available from one supplier in Japan. Thus, as discussed in sec tion 3.5.3, two prices are necessary because finished transformers imported from Mexi co and Canada would not be subject to the tariff. The Department analyzed designs at both price points, to ensure thatthe standard would not result in a competitive advantage to non-US manufacturers due to the import duty on ZDMH core steel. The wire and strip prices shown in Tabl e 5.4.1 were obtained from a major U.S. wire manufacturer.

In addition to these variable materials which the design software considers when preparing its optimized designs, there are other materials that are fixed and do not influence the design of the product. These include material s like the transformer cabinet, the high- and lowvoltage bushings, and the core clamps. Tabl e 5.4.3, on the next page, outlines all the estimated fixed material costs for each of th e five liquid-immersed design lines.
For design line 1, a 50kVA single-phase pad-m ounted unit, the high-voltage bushings are two universal bushing wells, 15 kV, 95 BIL, 7200V , costing $7 for the set. The low-voltage bushings are three copper studs, 240/120V, 50 kVA, at$8 for the set. The fuse system specified is a bayonet fuse holder, fuse and isolation link, costing $35. Th e internal hardware includes a core clamp, tap changer, nameplate, and other miscellaneous hardwa re costing $28.65. The Department varied the finished tank sizes for design line 1, ranging in price from $210 for the smallest size to $250 for the largest. Table 5.4.2 shows the five tank sizes used in design line 1. The Department based tank-size selections on the dimensions of the core-coil assembly, and based the oil used in the design on the core-c oil assembly displaceme nt of the tank volume.
Table 5.4.2 Variable Tank Sizes for Design Line 1

Tanks Length Height Depth Volume (cubic inches)* Volume (gal)* Price ($) Weight (lbs) A 32 24 13 8,320 36.0 $210 167 B 32 24 15 9,600 41.6 $220 174 C 32 24 17 10,880 47.1 $230 181 D 32 24 19 12,160 52.6 $240 188 E 32 24 21 13,440 58.2 $250 195 * Note that the volume calculation is less a four inch air-gap in the height of the tank.5-40 For design line 2, a 25kVA single-phase pole- mounted unit, the high-voltage terminalsare two porcelain bushing assemblies, 15 kV, 125 BIL, costing $12.00 for the set. The lowvoltage terminals are three porcelain bushings, 120/240V, 25 kVA, at $8.00 for the set. The Department specified no fuse system for this repr esentative unit. The internal hardware includes a core clamp, tap changer, nameplate, and other miscellaneous hardware, costing $28.65. The finished tank sizes are determined by the design so ftware. Rather than us e five discrete sizes as in design line 1, the software calculates ta nk size based on core/coil clearances and oil requirements. The price for a 25kVA pole- mounted tank is held constant at $120.
For design line 3, a 500kVA single-phase unit, the high-voltage connectors are two porcelain bushings, 25 kV, 125 BIL, costing $20 for the set. The low-voltage bushings are two polymer 500kVA, 277V, costing $40 for the set. Th e internal hardware includes a core clamp ($30), tap changer ($15), and nameplate and miscellaneous hardware ($20), totaling $65. As with design line 2, the software was allowed to vary the tank size . The finished round tank has a diameter of 26" to 30" with external cooling, and has a fixed cost of $500.
For design line 4, a 150kVA three-phase, pad- mounted unit, the high-voltage bushings are six universal bushing wells, 8.3/14.4 kV, 95 BIL, costing $21 each. The low-voltage bushings are four copper studs at $12 each. The fu se system installed is a bayonet fuse holder, fuse, and isolation link, costing $105. The intern al hardware includes co re clamps ($45), tap changer ($40), and nameplate and miscellaneous hardware ( $45), totaling $130. The finished tank sizes were determined by th e design software, measuring 48 inches high and 54 inches wide, and varying the depth. The finishedrectangular welded tank costs $650.
For design line 5, a 1500kVA three-phase, pad- mounted unit, the high-voltage bushings are six universal bushing wells, 15.2/26.3 kV, 125kV BIL, costing $42 for the set. The lowvoltage bushings are four copper studs, costing $12 each. The fuse system installed is a bayonet fuse holder, fuse, and isolation link costing $105. The internal hardware includes core clamps ($45), tap changer ($40), and nameplate and miscellaneous hardware ($45), totaling $130. The finished tank sizes were determined by the de sign software, measuring 60 inches high and 57 inches wide, and varying the depth. The finished rectangular welded tank costs $800.
Table 5.4.3 Summary Table of Fixed Materi al Costs for Liqu id-Immersed Units Item DL1 DL2 DL3 DL4 DL5 High voltage bushings $7 $12 $20 $21 $42 Low voltage bushings $8 $8 $40 $12 $12 Fuse system $35 none none $105 $105 Core clamp, tap changer, misc. hardware $28.65 $28.65 $65 $130 $130

Transformer tank $210-250 $120 $500 $650 $8005-41 5.4.2 Material Inputs to the Design Software - Dry-type
On the following pages, all the material costs entered into the design software for drytype distribution transformers are given. As s hown in these tables, the Department marked up the material costs before being entering them into the design software.
Table 5.4.4 Variable Material Inputs for Dry-Type Units
Item and DescriptionMaterialCost*Scrap andHandling**FactoryOverhead***Nonproduction****Input to designsoftware

H-O DR core steel (las er-scribed) $1.15 1.025 1.125 1.25 $1.66 M3 core steel $0.95 1.025 1.125 1.25 $1.37 M4 core steel $0.85 1.025 1.125 1.25 $1.23 M6 core steel $0.80 1.025 1.125 1.25 $1.15 M19 core steel (26 gauge) $0.70 1.025 1.125 1.25 $1.01 M36 core steel (26 gauge) $0.46 1.025 1.125 1.25 $0.66 M43 core steel (26 gauge) $0.39 1.025 1.125 1.25 $0.56 Copper wire, rectangular 0.1 x 0.2, Nomex wrapped $1.60 1.025 1.125 1.25 $2.31

Aluminum wire, rectangular 0.1 x 0.2, Nomex wrapped $2.00 1.025 1.125 1.25 $2.88
Copper strip, thickness range .02-.045 $2.40 1.025 1.125 1.25 $3.46 Aluminum strip, thickness range .02-.045 $1.30 1.025 1.125 1.25 $1.87 Nomex insulation (per pound) $17.50 1.025 1.125 1.25 $25.22 Impregnation (per gallon) $18.00 1.025 1.125 1.25 $25.95 Winding Combs (per pound) $10.00 1.025 1.125 1.25 $14.41 * Purchasing price to manufacturers from suppliers of raw materials necessary for building a transformer. Source: Paul Goethe, OPS, 2001; Manufacturer interviews, 2002. ** Handling and scrap is a multiplier factor that applies to variable materials (e.g., core steel, windings, insulation). It accounts for the handling of material (loading into asse mbly or winding equipment) and the scrap material that cannot be used in the production of a finished transformer (e.g., lengths of wire too short to wind, trimmed core steel). Source: Paul Goethe, OPS; Manufacturer interviews, 2002. *** Factory overhead includes all indirect costs associated with production, energy use (e.g., furn ace), light bulbs, insurance on factory and equipment, etc. Source: US Industry Census Data for 1992 and 1997; SEC 10-K reports for Acme, Powell, Magnetek and Hammond; Manufacturer interviews, 2002. **** Material mark up reflects non-production costs, including sales and general administrative, R&D, interest payments, and profit factor markups. Source: US Industry Census Data for 1992 and 1997; SEC 10-K reports for Acme, Powell, Magnetek and Hammond; Manufacturer interviews, 2002.5-42 In addition to the variable inputs presented in Table 5.4.4, there is one input material that varied for each of the design lines: the dog-bone cooling duct spacer. The number and placement of cooling ducts is determined by the design software during the design process; however, the size (height) of the duct is defined as a design input. In addition to presenting some of the fixed material costs, Ta ble 5.4.5 presents the input costs pe r foot for the duct-spacers used.
For design line 6, a 25kVA single-phase, low-voltage, dry-type, the fixed hardware costs are $4 for the low-voltage and high-voltage terminals. The mounting frame for attaching the core/coil assembly to the tr ansformer enclosure costs $9.25. The fiberglass dog-bone ductspacers used for this design line cost $0.24 per f oot. The miscellaneous hardware costs were set at $4.50. The enclosure itself, a 14-gauge steel enclosure, ba se, and mounting feet cost $100. The cost of the enclosure was held constant wh ile the actual dimensions were allowed to vary with the core-coil assembly size.
For design line 7, a 75kVA three-phase, low-vo ltage, dry-type, the fixed hardware costs are $6 for the low-voltage and high-voltage terminals. The low voltage bus-bar is estimated to be six feet at $1.50 per foot, or $9. The mounting frame that attaches the core/coil assembly to the transformer enclosure costs $19. The fiberglass dog-bone duct-spacers used for this design line cost $0.32 per foot. The miscellaneous hardware costs were estimated at $6. The enclosure itself, a 14-gauge steel enclosure, base, and mounting f eet cost $125. The cost of the enclosure was held constant while the actual dimensions were allowed to vary with the core-coil assembly size.
For design line 8, a 300 kVA three-phase, lo w-voltage, dry-type, the low-voltage and high-voltage terminal set costs $19. The low-volta ge bus-bar is estimated to be nine feet at $2.50 per foot, or $22.50. The mounting frame that attaches the core/coil assemb ly to the transformer enclosure costs $36. The fiberglass dog-bone duc t-spacers used for this design line cost $0.42 per foot. The miscellaneous hardware costs were estimated at $12. The enclosure itself, a 14- gauge steel enclosure, base, and mounting feet cost $175. The cost of the enclosure was held constant while the actual dimensions were allowed to vary with the core-coil assembly size.
For design line 9, a 300 kVA three-phase medium -voltage dry-type at 45kV BIL, the lowvoltage and high-voltage terminal set costs $75. The low-voltage bus-bar is estimated to be nine feet at $6 per foot, or $54. The mounting frame that attaches the core/coil assembly to the transformer enclosure costs $36. The fiberglass dog-bone duct-spacers used for this design line cost $0.24 per foot. The miscellane ous hardware costs were es timated at $25. The enclosure itself, a 14-gauge steel enclosure, base, and mounting feet cost $175. The cost of the enclosure was held constant while the actual dimensions were allowed to vary with the core-coil assembly size.
For design line 10, a 1500 kVA three-phase medi um-voltage dry-type at 45kV BIL, the low-voltage and high-voltage te rminal set costs $120. The low voltage bus-bar is estimated to be ten feet at $14 per foot, or $140. The mounting frame that attaches the core/coil assembly to the transformer enclosure costs $120. The fiberglass dog-bone duct-spacers used for this design line cost $0.52 per foot. The miscellane ous hardware costs were es timated at $42. The enclosure5-43 itself, a 12-gauge steel enclosure, base, and mounting feet cost $500. The cost of the enclosure was held constant while the actual dimensions were allowed to vary with the core-coil assembly size.
For design line 11, a 300 kVA three-phase medi um-voltage dry-type at 95kV BIL, the low-voltage and high-voltage te rminal set costs $75. The low-vo ltage bus-bar is estimated to be ten feet at $8 per foot, or $80. The mounting frame that attaches the core/coil assembly to the transformer enclosure costs $42. The fiberglass dog-bone duct-spacers used for this design line cost $0.24 per foot. The miscellane ous hardware costs were es timated at $32. The enclosure itself, a 14-gauge steel enclosure, base and mounting feet cost $200. The cost of the enclosure was held constant while the actual dimensions were allowed to vary with the core-coil assembly size.
For design line 12, a 1500 kVA three-phase medi um-voltage dry-type at 95kV BIL, the low-voltage and high-voltage te rminal set costs $120. The low-vo ltage bus-bar is estimated to be fourteen feet at $12 per foot, or $168. The moun ting frame that attaches the core/coil assembly to the transformer enclosure costs $125. The fiberglass dog-bone duct-spacers used for this design line cost $0.56 per foot. The miscellaneous hardware costs were estimated at $42. The enclosure itself, a 12-gauge steel enclosure, base and mounting f eet cost $600. The cost of the enclosure was held constant while the actual dimensions were allo wed to vary with the core-coil assembly size.
For design line 13, a 2000 kVA three-phase medi um-voltage dry-type at 125kV BIL, the low-voltage and high-voltage te rminal set costs $150. The low-vo ltage bus-bar is estimated to be eighteen feet at $15 per foot, or $270. The moun ting frame that attaches the core/coil assembly to the transformer enclosure costs $175. The fiberglass dog-bone duct-spacers used for this design line cost $0.60 per foot. The miscellaneous hardware costs were estimated at $56. The enclosure itself, a 12-gauge steel enclosure, base and mounting f eet cost $750. The cost of the enclosure was held constant while the actual dimensions were allo wed to vary with the core-coil assembly size.

Table 5.4.5 Summary Table of Fixed Ma terial Costs for Dry-Type Units
Item DL6 DL7 DL8 DL9 DL10 DL11 DL12 DL13 LV and HV terminals (set) $4 $6 $19 $75 $120 $75 $120 $150
LV bus-bar n/a $9 $22.50 $54 $140 $80 $168 $270 Core/coil mounting frame $9.25 $19 $36 $36 $120 $42 $125 $175 Dog-bone duct-spacer (ft.) $0.24 $0.32 $0.42 $0.24 $0.52 $0.24 $0.56 $0.60
Misc. hardware $4.50 $6 $12 $25 $42 $32 $42 $56 Enclosure (12, 14 gauge) $100 $125 $175 $175 $500 $200 $600 $7505-44 5.4.3 Labor Cost Inputs to the Design Software
Labor costs constitute a critical aspect of the cost of manufacturing a distribution transformer. As an input to the design software, the Department used the same hourly labor cost for both liquid and dry-type distribution transfor mers. The Department developed the hourly cost of labor using a similar approach to the development of the cost of materials; however, it used different markups except for the non-producti on markup. The Department developed the markups shown in Table 5.4.6 afte r reviewing publicly available information and consulting with industry experts familiar with transformer manufacturing in the U.S.
Table 5.4.6 Labor Markups for Liquid-I mmersed and Dry-Type Manufacturers Item description Markup percentage Rate per hour Labor cost per hour * $ 14.31
Indirect Production ** 33% $ 19.03
Overhead *** 30% $ 24.74 Fringe † 21% $ 29.93 Assembly Labor Up-time †† 43% $ 42.77 Non-Production Mark-up ††† 25% $ 53.46 Cost of Labor Input to Software $ 53.46 * Cost per hour is from U.S. Census Bureau, 1997 Economic Census of Industry , published September 1999, Table 5, page 9. Data for NAICS code 3353111 "Power and distribution transformers, except parts" Production workers hours and wages. ** Indirect Production Labor (Production managers, quality contro l, etc.) as a percent of direct labor on a cost basis. Navigant Consulting, Inc. (NCI) estimate. *** Overhead includes commissions, dismissal pay, bonuses, v acation, sick leave, and social security contributions. NCI estimate. † Fringe includes pension contributions, group insurance premiums, workers compensation. Source: U.S. Census Bureau, 1997 Economic Census of Industry , published September 1999, Table 3, page 8. Data for NAICS code 335311 "Power, Distribution and Specialty Transformer 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 42 per cent represents a 70 percent utilization (multiplying by 100/70). NCI estimate. ††† Non-production markup reflects non-production costs, including sales and general administrative, R&D, interest payments, and profit factor markups. Source: US Industry Census Data for 1992 and 1997; SEC 10-K reports for Acme, Powell, Magnetek and Hammond; Manufacturer interviews, 2002.5-45 5.5 RESULTS OF THE ANALYSIS ON EACH DESIGN LINE
This section provides a visual representation of the results of the engineering analysis. The scatter plots in this section show the cost and efficiency relationshi ps for each of the 13 design lines. Each dot on the plots represents one unique design created by the software at a given manufacturer selling price and efficiency level. The placement of each dot (and the uniqueness of each design) is dictated by the design option combinations (core steel and windings), core shape, and A/B combination. InAppendix 5A, additional scatter plots for the engineering analysis results for the 13 representa tive units are presented, including watts of core and coil loss by price and the weight by price. On the Department’s we bsite, the actual values behind these plots are available in two Microsoft Excel® workbooks, one for liquid-immersed and one for dry-type units. See: http://www.eere.energy.gov/buildings/appliance_ standards/commercial/d ist_transformers.html
Figure 5.5.1 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 1. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:
• Designs achieving the highest efficiencies at the lowest costs are based on M2 and M3 steel cores. Of these cores, the M3CuAl offers the least-cost option for improving efficiency, but is limited to an efficiency of 99.3 percent. • The all-copper windings ava ilable with the M2CuCu and M3CuCu options allow for somewhat higher effici encies, but the costs escalate rapidly above 99.3 percent efficiency. • The ZDUS (ZDMH core steel) has higher costs associated with increasing efficiency than do other cores. • The amorphous metal (SA1) core dramatically extends the av ailable efficiency for the transformers beyond 99.6 percent, but at a significant cost.5-46 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800

98.40% 98.60% 98.80% 99.00% 99.20% 99.40% 99.60% 99.80% Efficiency at 50% Load, Temperature Corrected (%)Manufacturer Selling Price ($) SA1CuCu M2CuAl M2CuCu M3AlAl M3CuAl M3CuCu M6AlAl M6CuAl ZDUSCuCu

Figure 5.5.1 Scatter Plot of Manufacturer Selling Price and Efficiency for DL15-47 Figure 5.5.2 Scatter Plot of Manufacturer Selling Price and Efficiency for DL2 Figure 5.5.2 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 2. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:
• The TP-1 standard of 98.7 percent can be achieved with se veral design option combinations, including M6AlAl and M4AlAl. • The ZDUS core has higher costs associated with increasing efficiency relative to the other design option combinations. • In most cases, the maximum efficiency av ailable with conven tional core steels is approximately 99.2 percent. However, the amorphous metal (SA1) provides efficiencies up to about 99.5 percent. • For this kVA rating, the SA1 core has a very steep cost curve associated with increasing efficiency.5-48 Figure 5.5.3 Scatter Plot of Manufacturer Selling Price and Efficiency for DL3 Figure 5.5.3 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 3. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:
• The Japanese deep-domain refined core steel (ZDMH) design option combination, ZDUSCuCu, has higher costs associated with increasing efficiency relative to the other design options. • In most cases, the maximum efficiency ava ilable is limited to appr oximately 99.6 percent. However, the amorphous metal design opti on combination provides efficiencies up to about 99.8 percent, with an available range from about 99.5 percent to nearly 99.8 percent. • Beyond the efficiencies availa ble with other cores, the am orphous core has a flat cost with increasing efficiency up to about 99.6 per cent. Beyond that, the costs begin to rise exponentially.5-49 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000

97.50% 98.00% 98.50% 99.00% 99.50% 100.00% Efficiency at 50% Load, Temperature Corrected (%)Manufacturer Selling Price ($) SA1CuCu M2CuAl M4AlAl M3CuAl M2CuCu M6AlAl ZDUSCuCu M3CuCu

Figure 5.5.4 Scatter Plot of Manufacturing Selling Price and Efficiency for DL4 Figure 5.5.4 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 4. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:
• At the lower efficiencies, the M6 and M4 steel cores offer a low-cost option for increasing efficiency. • Between 99.0 percent and 99.4 percent, the M2 and M3 steel cores are a cost-efficient option for increasing efficiency. For these cores there is no significant difference between the all-copper a nd copper-aluminum windings. • The ZDUS core has a higher cost associated with increasing efficiency relative to the other steel core offerings. • The amorphous metal design op tion combination extends the av ailable efficiency for the transformers up to 99.6 percent, but at a significant cost.5-50 5000 10000 15000 20000 25000

99.10% 99.20% 99.30% 99.40% 99.50% 99.60% 99.70% 99.80% Efficiency at 50% Load, Temperature Corrected (%)Manufacturer Selling Price ($) SA1CuCu
M2CuAl
M4AlAl
M3CuAl
M4CuAl
ZDUSCuCu
M3AlAl

Figure 5.5.5 Scatter Plot of Manufacturing Selling Price and Efficiency for DL5 Figure 5.5.5 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 5. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate lo ad. Several observations can be made about this scatter plot:
• All the cores, except for the ZDUS, provide a low-cost option for increased efficiency between 99.2 percent and 99.5 percent. However, the optimal core and winding combination at a given efficiency rating vary. • Beyond 99.5 percent, the SA1 core provides a dditional efficiency with increased cost. However, the units with the lowest manufacturer selling prices follow a similar general trend displayed by the other cores. • From the least expensive to the most expensive, there is more than a three-fold difference in the manufacturer’s sales price.5-51 400 600 800 1000 1200 1400 1600

94.00% 95.00% 96.00% 97.00% 98.00% 99.00% Efficiency at 35% Load, Temperature Corrected (%)Manufacturer Selling Price ($) M43AlAlCo M36AlAlCo

M19AlAlCo M6AlAlCo

M3CuAlCo HOCuCuCo

M19AlAlSh M6AlAlSh

M3CuAlSh HOCuCuSh

Figure 5.5.6 Scatter Plot of Manufacturing Selling Price and Efficiency for DL6 Figure 5.5.6 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 6. The efficiency levels shown in this plot represent transformers at 35 percent of nameplate load and are corrected for temperature. Some observations can be made about this scatter plot:
• The least-expensive cores, M43, M36, a nd M19, do not meet the minimum efficiency level for NEMA’s TP 1-2002 for a 25kVA low- voltage, dry-type, si ngle-phase of 98.0 percent. • The H-O DR steel cores provide the high est efficiency but are limited to about 99.0 percent efficiency. At these higher efficiency levels, the cost of the transformers continues to rise with little or no gain in efficiency. • The M3 and M6 cores provide the least-co st option, from 97.5 percent to 98.5 percent, for increasing efficiency.5-52 Figure 5.5.7 Scatter Plot of Manufacturing Selling Price and Efficiency for DL7 Figure 5.5.7 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 7. The efficiency levels shown in this plot represent transformers at 35 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:
• The M3CuAlEv (Evans core) transformer ha s essentially the same costs and efficiency gains as the HOCuCuEv transformer. Howe ver, the H-O DR transformer provides a slightly higher efficiency than the M3 transformer. • At the higher efficiency levels, the cost of the transformers continues to rise with little or no gain in efficiency. • The M19 and M43 cores do not achieve th e minimum efficiency rating of 98.0 percent under NEMA’s TP 1-2002 for a 75kVA thr ee-phase LV dry-type transformer.5-53 Figure 5.5.8 Scatter Plot of Manufacturing Selling Price and Efficiency for DL8 Figure 5.5.8 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 8. The efficiency levels shown in this plot represent transformers at 35 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:

• The HOCuCu transformer does not appear to have any co st benefit over the M3CuAl transformer. At 99.0 percent efficiency, a tran sformer with the M3 steel core offers the least cost and at higher efficiencies has costs equal to those of the H-O DR core steel. • At the higher efficiency levels, the cost of the transformers continues to rise with little or no gain in efficiency. • The M19 core steel does not provide th e minimum efficiency of 98.6 percent under NEMA’s TP 1-2002.5-54 3000 4000 5000 6000 7000 8000 9000 10000

96.50% 97.00% 97.50% 98.00% 98.50% 99.00% 99.50% Efficiency at 50% Load, Temperature Corrected (%)Manufacturer Selling Price ($) M36AlAl
M19AlAl
M6AlAl
M3CuAl
HOCuCu
M6CuCu

Figure 5.5.9 Scatter Plot of Manufacturing Selling Price and Efficiency for DL9 Figure 5.5.9 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 9. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:
• The least-expensive units employ the l east-expensive core steels, M36 and M19. • Even though extremely high evaluation formulas are being applied to M36 and M19 steels (i.e., $12A and $8B), th e efficiencies are unable to improve beyond 98 percent. • NEMA’s TP 1-2002 efficiency level for this unit is 98.6 percent efficient. This level cannot be achieved using the less expensive M 36 and M19 core steels. This level can be achieved by using M6 or better core steels. • Rapid increase in price is realized in the M3 and H-O DR core steels, as the efficiency level increases. For example, moving a fr action of an efficiency level (e.g., from 99.00 percent to 99.25 percent) can double the price. • The increased performance and higher price of all-copper windings is shown when the M6AlAl design option combination is compar ed with the M6CuCu, although, at several efficiency points, M3CuAl appears to be a lower-cost option than M6CuCu.5-55 Figure 5.5.10 Scatter Plot of Manufacturing Selling Price and Efficiency for DL10 Figure 5.5.10 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 10. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:

• The M4 core steel combined with the copper-aluminum windings (M4CuAl) offers a more cost-effective design option than the a ll-copper or all-alumi num windings available with the M6 cores. • As the efficiency increases, the laser-scribed (H-O DR) and M3 steel cores have similar costs.5-56 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000

97.40% 97.60% 97.80% 98.00% 98.20% 98.40% 98.60% 98.80% 99.00% 99.20% 99.40% Efficiency at 50% Load, Temperature Corrected (%)Manufacturer Selling Price ($) M4CuAl

M6AlAl

M3CuCu

HOCuCu

M6CuCu

Figure 5.5.11 Scatter Plot of Manufacturing Selling Price and Efficiency for DL11 Figure 5.5.11 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for the de sign line 11. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load. Several observations can be made about this scatter plot:
• The least-cost high-efficiency design path at 50 percent load varies between the M3, M4, and H-O DR cores steel design option combinations. • The M6 cores offer the least-cost options only at the lowest efficiency levels. In general, the transformers that use the M6 core steel are not the most cost-effective option available. • Many design option combinations are possi ble that comply with the NEMA TP 1-2002 efficiency level of 98.5 percent for this 300kVA, three-phase medi um-voltage dry-type unit at 95kV BIL.5-57 10000 15000 20000 25000 30000 35000 40000 45000

98.60% 98.70% 98.80% 98.90% 99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% Efficiency at 50% Load, Temperature Corrected (%)Manufacturer Selling Price ($) M4CuAl

M6AlAl

M3CuCu

HOCuCu

M6CuCu

Figure 5.5.12 Scatter Plot of Manufacturing Selling Price and Efficiency for DL12 Figure 5.5.12 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 12. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate lo ad. Several observations can be made about this scatter plot:

• The M4 core steel combined with the copper-aluminum windings (M4CuAl) offers a more cost-effective design option than the a ll-copper or all-alumi num windings available with the M6 cores. • Above 99.3 percent efficiency, the H-O DR st eel design option combination has a slight cost advantage over the M3 core. Both provide a maximum efficiency of about 99.5 percent with similar costs. • In general, the transformers that use the M6 core steel are not the most cost-effective option available.5-58 20000 25000 30000 35000 40000 45000 50000 55000 60000

98.50% 98.60% 98.70% 98.80% 98.90% 99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% Efficiency at 50% Load, Temperature Corrected (%)Manufacturer Selling Price ($) M4CuAl

M6AlAl

M3CuCu

HOCuCu

M6CuCu

Figure 5.5.13 Scatter Plot of Manufacturing Selling Price and Efficiency for DL13 Figure 5.5.13 presents a plot of the manufacturer sales prices and efficiency levels for the full database of designs for th e representative unit from design line 13. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected for temperature. Several observations can be made about this scatter plot:

• The M3CuCu transformer offers the l east-cost option over an extended range of efficiencies, from slightly less than 99.0 percent up to nearly 99.5 percent. • The HOCuCu transformer does not appear to yield any cost reduction relative to the M3CuCu transformer. At efficiency levels of 99.2 percent and above, the M3 steel core and H-O DR steel cores have similar costs and efficiency gains. • The transformers that use the M6 steel ar e limited to an efficiency of about 99.25 percent and are only cost-effective up to about 99.0 percent.5-59 5.6 TWO EXAMPLE TRANSFORMER DESIGNS AND COST BREAKDOWNS
To provide some detail and establish credibility with its engineering analysis costefficiency database developed by the design software, the Department selected two designs from its database of over 20,000 to present in this section. Transformer engineers can review the design reports, and assess the quality of the designs. The two distribution transformers presented are the cost-optimized designs for two units, one each from design line 3 and design line 12. Across all the design lines, the complete database of designs c ontains 22,387 distribution transformer specification and winding sheets, bills of materials, and performance reports. This database is the output from the engineering analysis that is used in the LCC analysis.
Design Line 3: 500 kVA single-phase, liquid-immerse d, M6 core steel with an copper primary and an aluminum secondary (M6CuA l) at a $3.00 A and a $1.00 B evaluation formula.
Design Line 12: 1500 kVA three-phase, medium-voltage dry-type, M3 core steel with primary and secondary copper windings (M 3CuCu) at a $3.00 A and a $1.00 B evaluation formula.
For both designs presented, the design detail report is followed by a bill of materials showing the cost calculation, and a pie chart pr oviding a breakdown of the final selling price.

5.6.1 Results for DL3 Transformer, M6CuAl at $3 A and $1 B
A design specification report for a 500kVA si ngle-phase liquid-imme rsed transformer appears below. This design incorporates M6 core steel, with a copper primary and aluminum secondary. The evaluation factors for this desi gn are $3.00 A and $1.00 B. The bill of materials and associated breakdown of costs for this design are also reported, after the design and electrical analysis reports.

OPTIMIZED PROGRAM SERVICE

CLEVELAND OHIO 101800 2002- 3-22 9: 2:45 DG-CORE SHELL TYPE TRANSFORMER L3SM6CUAL
FREQUENCY 60.0 KVA RATING 499.85 @ 100.00% DUTY CYCLE

CORE DG-M6 M 6 THICKNESS .0140

D: 9.680 E: 4.083 F: 4.315 G:21.577 EFF. AREA 76.285 WEIGHT1354.749

WINDING FORM: INS. DIM. 10.180 X 8.541 THICKNESS .122 LENGTH 21.2655-60 COIL SPECIFICATIONS

-------------------

WNDG WIRE LENGTH MEAN TURNS MARGIN WT

---------------------------------------------------------------------- S1 2X 1(.0512X20.5148) AL 48.50 44.77 .375 119.358 P1 .1269X .2614 CU 3552.43 60.06 .750 442.697

NUMBER OF COILS 1 TOTAL BARE CONDUCTOR WEIGHT 562.055
WNDG TURNS LO TAP HI TAP LAYRS T/L LAYR INS SEC. INS BUILD

---------------------------------------------------------------------- S1 13.0 13 1.0 1(.02000) 1(.15000) 1.571 P1 676.0 642.2 709.8 10 71.0 6(.00500) 1(.15000) 1.589
TOTAL BUILD(%) 87.37
WNDG TAPS: TURNS( VOLTS)

---------------------------------------------------------- P1 659.1( 14040.00) 692.9( 14760.00) 709.8( 15120.00)

WNDG INTERNAL DUCTS(100.00) %EFF EXTERNAL DUCTS(100.00) %EFF

---------------------------------------------------------------- S1 3 .188 X .188 IN. END P1 3 .188 X .188 IN. END .188 X .188 IN. FULL

ELECTRICAL ANALYSIS

-------------------

FULL-LOAD TAP VOLTS TEST LOAD RESIST. CURRNT WNDG VOLTS LOW HIGH KV CURRENT @20 C. DENS. %REG

---------------------------------------------------------------------- P1 14400.00 13680.00 15120.00 34.5 34.977 .89491 1082. S1 275.04 10.0 1805.000 .00031 860. .7

F.L. N.L. FLUX DENS. 16.175 16.240 LEAKAGE INDUCTANCE MHYS 56.817 CORE LOSS 987.255 999.001 POWER FACTOR 1.0000 COIL LOSS 2908.687 .011 IMPEDANCE % 5.23 EXCIT. VA 1328.606 1364.913 EFFICIENCY % 99.23 EXCIT. CURR. .092 .095 TANK OIL GAL 69.04

AMBIENT TEMP. 20.00 NOMINAL LENGTH 24.96 TEMP.RISE 65.00 NOMINAL DEPTH 21.06 OPERATING TEMP. 85.00 NOMINAL HEIGHT 29.74

AVG. OIL RISE: 50. TOP OIL RISE: 76.6 TANK DIMENSIONS

------------------- LENGTH = 25.963 DEPTH = 22.061 OIL HEIGHT = 41.743

25-61 COND. I R LOSS = 2662.5920 COND. EDDY CURRENT LOSS = 166.2170 OTHER STRAY LOSS = 79.8778 K VALUE = 1.0000

%LOAD %REG %EFF %IR %IX %IZ COIL LOSS TEMP. RISE

------------------------------------------------------------------------ 25 .13 99.08 .123 1.303 1.309 168.913 39.1 35 .19 99.24 .174 1.821 1.829 335.370 44.1 50 .29 99.32 .258 2.599 2.612 705.026 54.7 65 .41 99.32 .346 3.379 3.396 1226.960 65.0 75 .48 99.30 .399 3.899 3.920 1633.676 65.0 100 .67 99.23 .533 5.203 5.230 2908.687 65.0 125 .89 99.12 .666 6.510 6.544 4553.014 65.0 150 1.12 99.00 .801 7.821 7.862 6569.333 65.0 Following is the breakdown of costs, or the 'bill of materials,' associated with this design, M3 core steel, with an alumi num primary and copper secondary.5-62 Bill of Materials and Labor for 1 phase, 500kVA liquid-type round-tank A$ Input $3.00 B$ Input $1.00

Material item Type Quantity $ each $ total Core Steel* (lb) M6 1355 0.64 $ 867.04 $ Primary winding* (lb) Copper 443 1.30 $ 575.51 $ Secondary windings* (lb) Aluminum 119 1.30 $ 155.17 $ Winding form & insulation* (lb) Kraft Paper 25 1.54 $ 39.18 $ Oil (gal)

- 70 1.50 $ 104.94 $ Tank round 1 506.35 $ 506.35 $ Core Clamp

- 1 30.00 $ 30.00 $ Tap Changer

- 1 15.00 $ 15.00 $ Bushings HV & LV 1 60.00 $ 60.00 $ Misc. Hardware

- 1 20.65 $ 20.65 $
Handling and Scrap Factor 2.5% 40.92 $ Total Material Cost 2,414.76 $

Labor item hours rate $ total Setup & wind primary 1.42 42.77 60.72 $ Setup & wind secondary 0.90 42.77 38.29 $ Banding core metal 0.50 43.77 21.89 $ Assembly (coils, yoke & clamping) 0.75 42.77 32.08 $ Lead dressing 0.35 42.77 14.97 $ Inspection 0.10 42.77 4.28 $ Preliminary and Final Test 0.25 42.77 10.69 $ Shipment Packing and Marking 0.55 42.77 23.52 $ Miscellaneous (incl. VPI) 0.30 42.77 12.83 $

Total Labor 5.115 42.77 218.76 $
Manufacturing Cost (Material + Labor) 2,633.52 $ Factory Overhead (Materials only) 12.5% 301.84 $ Selling Factor 25.0% 733.84 $
Manufacturer Selling Price 3,669.21 $
* indicates those items to which the handling and scrap factor (2.5%) is applied Table 5.6.1 Bill of Materials for Example Design from DL3 Database5-63 Figure 5.6.1 Cost Breakdown for DL3 M6CuAl Design at $3A, $1B Figure 5.6.1 provides a summary of the costs c ontributing to the total selling price of the DL3 representative unit. For this design, approximately 66 percent of the final manufacturer selling price of an M3, aluminum primary and c opper secondary, is directmaterial and scrap. Labor accounts for 6 percent of the pri ce, and overheads account for 28 percent.5-64 5.6.2 Results for DL12 Transformer, M3CuCu at $3A and $1B
The following design report provides information on one of several designs prepared tostudy the representative unit from design line 12. This is a 1500kVA, three-phase, mediumvoltage, dry-type unit at 95kV BIL. The designshown here (out of the 1,344 designs in the database) is for M3 core steel with a copper primary and secondary, and a $3.00A and $1.00B.

OPTIMIZED PROGRAM SERVICE

CLEVELAND OHIO 101800 2002- 8- 9 11:35: 2 STRIP CRUC 3-PHASE TYPE TRANSFORMER L12M3CUCU FREQUENCY 60.0 MVA RATING 1.50 @ 100.00% DUTY CYCLE CORE 10.063" CRUC STACK 10.063 GRADE M 3 THICKNESS .0090 WINDOW: 15.241 X 47.372 EFF. AREA 76.894 WEIGHT 5591.294 WINDING FORM:INS. DIM. 10.598 X 10.598 THICKNESS .156 LENGTH 45.372

COIL SPECIFICATIONS

-------------------

WNDG WIRE LENGTH MEAN TURNS MARGIN WT

---------------------------------------------------------------------- S1 3X 1(.0124X37.3721) CU 51.62 44.24 4.000 276.774 P1 .1190X .3225 CU 3850.89 69.86 5.750 557.192

NUMBER OF COILS 3 TOTAL BARE CONDUCTOR WEIGHT 2501.897
WNDG TURNS LO TAP HI TAP LAYRS T/L LAYR INS SEC. INS BUILD

---------------------------------------------------------------------- S1 14.0 14 1.0 1(.00700) 1(.20000) 3.112 P1 630.0 598.5 661.5 14 1.0 1(.00001) 1(.00001) 1.890
TOTAL BUILD(%) 90.23
WNDG TAPS: TURNS( VOLTS)

---------------------------------------------------------- P1 614.3( 12158.25) 645.8( 12781.75) 661.5( 13093.50)

DISK INFORMATION

----------------- WNDG DISK WIDTH VOLTS/DISK BREAK TAPS SPACE

------------------------------------------------------- P1 48 .338 272.781 .375 2(.38) 44( .375)

WNDG INTERNAL DUCTS( 95.00) %EFF EXTERNAL DUCTS( 95.00) %EFF

---------------------------------------------------------------- S1 4 .625 X .625 IN. FULL P1 2 .625 X .625 IN. FULL5-65 WNDG INT. DUCT AREA EXT. DUCT AREA TOTAL DUCT AREA

--------------------------------------------------------- S1 9931.7920 1671.3810 11603.1700 P1 .0000 2278.9760 5815.4850

ELECTRICAL ANALYSIS

-------------------

FULL-LOAD TAP VOLTS TEST LOAD RESIST. CURRNT WNDG VOLTS LOW HIGH KV CURRENT @20 C. DENS. %REG

---------------------------------------------------------------------- P1 12470.00 D 11846.50 13093.50 18.0 40.431 .83551 1077. S1 274.72 W 4.0 1804.300 .00030 1297. .9

F.L. N.L. FLUX DENS. 14.882 14.971 LEAKAGE INDUCTANCE MHYS 58.391 CORE LOSS 2794.702 2841.611 POWER FACTOR 1.0000 COIL LOSS 10076.760 .039 IMPEDANCE % 7.16 EXCIT. VA 3808.522 3899.871 EFFICIENCY % 99.15 EXCIT. CURR. .102 .104 OPEN ALT. DUCT 3 .00

AMBIENT TEMP. 20.00 NOMINAL LENGTH 75.91 TEMP.RISE 76.58 NOMINAL DEPTH 24.32 OPERATING TEMP. 96.58 NOMINAL HEIGHT 67.50

WINDING: S1 P1

TEMP RISE: 77. 63.

2 COND. I R LOSS = 8916.1750 COND. EDDY CURRENT LOSS = 803.9380 OTHER STRAY LOSS = 356.6469 K VALUE = 1.0000

WIRE WRAP PER COIL WNDG THICKNESS WEIGHT

------------------------- P1 .00800 9.64374

%LOAD %REG %EFF %IR %IX %IZ COIL LOSS TEMP. RISE

------------------------------------------------------------------------ 25 .15 99.10 .128 1.786 1.790 554.804 30.5 35 .21 99.26 .181 2.496 2.502 1096.539 33.9 50 .33 99.32 .264 3.563 3.573 2281.396 40.9 65 .47 99.31 .354 4.632 4.646 3953.208 49.7 75 .57 99.28 .418 5.346 5.363 5365.097 56.5 100 .86 99.15 .594 7.137 7.162 10076.760 76.6 125 1.21 98.97 .797 8.937 8.973 16764.860 100.6 150 1.64 98.74 1.033 10.748 10.798 25853.470 128.25-66 Bill of Materials and Labor for 3 phase, 1500kVA dry-type, 95kV BIL A$ Input $3.00 B$ Input $1.00

Material item Type Quantity $ each $ total Winding Form* (lb) Nomex 29.71 17.50 $ 519.84 $ Core Steel* (lb) M3 5591 0.95 $ 5,311.73 $ Primary winding* (lb) Copper - Wire 1672 1.60 $ 2,674.52 $ Secondary winding* (lb) Copper - Strip 830 2.40 $ 1,992.77 $ Winding Insulation* (lb) Nomex 71 17.50 $ 1,245.05 $ Winding Comb* (lb) 91 10.00 $ 908.77 $ Duct Spacer* (ft) Dog-bone 1553 0.56 $ 869.73 $ Enclosure 14 gauge 1 600.00 $ 600.00 $ Mounting Frame

- 1 125.00 $ 125.00 $ Buss-bar (ft)

- 14 12.00 $ 168.00 $ Start & finish terminals HV & LV 15 8.00 $ 120.00 $ Varnish impregnation (gal) 27 18.00 $ 485.43 $ Misc. Hardware

- 1 42.00 $ 42.00 $
Handling and Scrap Factor 2.5% 338.06 $ Total Material Cost 15,400.90 $

Labor item hours rate $ total Setup & wind primary (3 phase) 4.96 42.77 212.19 $ Setup & wind secondary (3 phase) 2.85 42.77 122.05 $ Stacking core metal 8.05 42.77 344.32 $ Assembly (coils, yoke & clamping) 6.00 42.77 256.62 $ Lead dressing (3 phase) 1.00 42.77 42.77 $ Inspection 0.25 42.77 10.69 $ Preliminary and Final Test 1.25 42.77 53.46 $ Shipment Packing and Marking 2.20 42.77 94.09 $ Miscellaneous (incl. VPI) 2.00 42.77 85.54 $

Total Labor 28.565 42.77 1,221.74 $
Manufacturing Cost (Material + Labor) 16,622.64 $ Factory Overhead (Materials only) 12.5% 1,925.11 $ Selling Factor 25.0% 4,636.94 $
Manufacturer Selling Price 23,184.69 $ * indicates those items to which the handling and scrap factor (2.5%) is applied Table 5.6.2 Bill of Materials for Example Design from DL12 Database Table 5.6.2 provides a breakdown of costs, or th e “bill of materials,” associated with this design, 1500kVA three-phase medium -voltage (95kV BIL) dry-type with M3 core steel and copper primary and secondary windings. The ev aluation factors for this design are $3.00 A and $1.00 B.5-67 Figure 5.6.2 Cost Breakdown for DL12, M3CuCu Design at $3A, $1B. Figure 5.6.2 provides a summary of the costs c ontributing to the total selling price of the transformer detailed above. Approximately 67 pe rcent of the final selling price is material-based: core, coil, insulation, and other materials. Labor accounts for a pproximately 5 percent of the price, and overheads account for about 28 percent.