5-i CHAPTER 5. ENGINEERING ANALYSIS

TABLE OF CONTENTS

5.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.2 STRUCTURING THE ENGINEERING ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.2.1 Summary of Design Line Coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7 5.2.2 Scaling Relationships in Transformer Manufactu ring . . . . . . . . . . . . . . . . . . . . . . 5-9 5.3 TECHNICAL DESIGN INPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12 5.3.1 Design Line 1 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18 5.3.2 Design Line 2 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 5.3.3 Design Line 3 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 5.3.4 Design Line 4 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 5.3.5 Design Line 5 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21 5.3.6 Design Line 9 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22 5.3.7 Design Line 10 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 5.3.8 Design Line 11 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24 5.3.9 Design Line 12 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25 5.3.10 Design Line 13 Representative Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 5.4 MATERIAL AND LABOR INPUTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27 5.4.1 Material Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29 5.4.2 Material Inputs to the Design Software—Liquid- Immersed . . . . . . . . . . . . . . . . 5-30 5.4.3 Material Inputs to the Design Software—Dry-typ e . . . . . . . . . . . . . . . . . . . . . . . 5-33 5.4.4 Labor Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-37 5.5 RESULTS OF THE ANALYSIS ON EACH DESIGN LINE . . . . . . . . . . . . . . . . . . . . . 5-44 5.6 FOUR EXAMPLE TRANSFORMER DESIGNS AND COST BREAKD OWNS . . . . . 5-55 5.6.1 Design Details Report for Non-Evaluated Transf ormer from Design Line 1 . . . 5-55 5.6.2 Design Details Report for Evaluated Transforme r from Design Line 1 . . . . . . . 5-59 5.6.3 Design Details Report for Non-Evaluated Transf ormer from Design Line 12 . . 5-63 5.6.4 Design Details Report for Evaluated Transforme r from Design Line 12 . . . . . . 5-67 5.7 TEAR-DOWN ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-71

LIST OF TABLES Table 5.2.1 Product Classes and Number of kVA Rating s . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 Table 5.2.2 Engineering Design Lines (DLs) and Repre sentative Units for Analysis . . . . . . . 5-3 Table 5.2.3 Liquid-Immersed Design Lines and Represe ntative Units . . . . . . . . . . . . . . . . . . 5-7 Table 5.2.4 Dry-Type, Medium-Voltage, Single-Phase D esign Lines . . . . . . . . . . . . . . . . . . . 5-8 Table 5.2.5 Dry-Type, Medium-Voltage, Three-Phase De sign Lines . . . . . . . . . . . . . . . . . . . . 5-9 Table 5.2.6 Common Scaling Relationships in Transfor mers . . . . . . . . . . . . . . . . . . . . . . . . 5-10 Table 5.3.1 A and B Grid Combinations used by Softwa re to Generate Design Database . . 5-13 Table 5.3.2 A and B Fan Combinations used by Softwar e to Generate Design Database . . . 5-14 Table 5.3.3 Core Steel Grades, Thicknesses and Assoc iated Losses . . . . . . . . . . . . . . . . . . . 5-15 Table 5.3.4 Core Configurations Used in Each Design Line . . . . . . . . . . . . . . . . . . . . . . . . . 5-16 Table 5.3.5 Design Option Combinations for the Repre sentative Unit from Design Line 1 . 5-18 Table 5.3.6 Design Option Combinations for the Repre sentative Unit from Design Line 2 . 5-195-ii

Table 5.3.7 Design Option Combinations for the Repre sentative Unit from Design Line 3 . 5-20 Table 5.3.8 Design Option Combinations for the Repre sentative Unit from Design Line 4 . 5-21 Table 5.3.9 Design Option Combinations for the Repre sentative Unit from Design Line 5 . 5-22 Table 5.3.10 Design Option Combinations for the Repr esentative Unit from Design Line 9 . 5-23 Table 5.3.11 Design Option Combinations for the Repr esentative Unit from Design Line 10 5-24 Table 5.3.12 Design Option Combinations for the Repr esentative Unit from Design Line 11 5-25 Table 5.3.13 Design Option Combinations for the Repr esentative Unit from Design Line 12 5-26 Table 5.3.14 Design Option Combinations for the Repr esentative Unit from Design Line 13 5-27 Table 5.4.1 Manufacturer’s Material Prices for Liqui d-Immersed Design Lines . . . . . . . . . . 5-30 Table 5.4.2 Marked-up Material Prices for Liquid-Imm ersed Units, Five-Year Average

Price Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31 Table 5.4.3 Summary Table of Fixed Material Costs fo r Liquid-Immersed Units . . . . . . . . . 5-33 Table 5.4.4 Manufacturer’s Material Prices for Dry-T ype Design Lines . . . . . . . . . . . . . . . . 5-34 Table 5.4.5 Marked-up Material Prices for Dry-Type U nits, Five-Year Average Price

Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35 Table 5.4.6 Summary Table of Fixed Material Costs fo r Dry-Type Units . . . . . . . . . . . . . . . 5-37 Table 5.4.7 Labor Markups for Liquid-Immersed and Dr y-Type Manufacturers . . . . . . . . . . 5-38 Table 5.4.8 Summary of Labor Times for Liquid-Immers ed Units . . . . . . . . . . . . . . . . . . . . 5-41 Table 5.4.9 Summary of Labor Times for Dry-Type Unit s . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-43 Table 5.6.1 Bill of Materials for Non-Evaluated Tran sformer from Design Line 1 . . . . . . . . 5-58 Table 5.6.2 Bill of Materials for Evaluated Transfor mer from Design Line 1 . . . . . . . . . . . . 5-62 Table 5.6.3 Bill of Materials for Non-Evaluated Tran sformer from Design Line 12 . . . . . . . 5-66 Table 5.6.4 Bill of Materials for Evaluated Transfor mer from Design Line 12 . . . . . . . . . . . 5-70

LIST OF FIGURES Figure 5.3.1 A and B Combination Software Inputs use d in the Engineering Analysis . . . . . 5-14 Figure 5.3.2 Graphic of Single-Phase Core Configurat ions . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16 Figure 5.3.3 Graphic of Three-phase Core Configurati ons . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17 Figure 5.3.4 Cruciform Core Cross-Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17 Figure 5.4.1 Standard Method of Cost Accounting for Standards Rulemaking . . . . . . . . . . . . 5-27 Figure 5.5.1 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 1 . . . 5-45 Figure 5.5.2 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 2 . . . 5-46 Figure 5.5.3 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 3 . . . 5-47 Figure 5.5.4 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 4 . . . 5-48 Figure 5.5.5 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 5 . . . 5-49 Figure 5.5.6 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 9 . . . 5-50 Figure 5.5.7 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 10 . . 5-51 Figure 5.5.8 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 11 . . 5-52 Figure 5.5.9 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 12 . . 5-53 Figure 5.5.10 Scatter Plot of Manufacturer Selling P rice and Efficiency for Design Line 13 . . 5-54 Figure 5.6.1 Manufacturer Selling Price Breakdown, N on-Evaluated Transformer from

Design Line 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-59 Figure 5.6.2 Manufacturer Selling Price Breakdown, E valuated Transformer from

Design Line 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-63 Figure 5.6.3 Manufacturer Selling Price Breakdown, N on-Evaluated Transformer from5-iii D esign Line 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-67 Figure 5.6.4 Manufacturer Selling Price Breakdown, Evaluated Transformer from

Design Line 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-71 Figure 5.7.1 Tear-down Plot Comparison, Design Line 7, 75kVA Three-phase Dry-type . . . 5-73a

NEMA’s TP 1-2002 can be found online at: http://www.nema.org/stds/tp1.cfm#download
5-1 CHAPTER 5. ENGINEERING ANALYSIS

5.1 INTRODUCTION This chapter provides the technical support documen tation on the engineering analysis, evaluating both liquid-immersed and dry-type distri bution transformers. The purpose of the engineering analysis is to estimate the relationshi p between the manufacturer’s selling price of a transformer and its corresponding efficiency rating . This relationship serves as the basis for the subsequent cost-benefit calculations for individual consumers, manufacturers, and the nation (see Chapter 8, Life-Cycle Cost and Payback Period Analyses).

5.2 STRUCTURING THE ENGINEERING ANALYSIS As discussed in the market and technology assessmen t (Chapter 3), distribution transformers are classified by their insulation type (liquid-imm ersed or dry-type), the number of phases (single or three), and the basic impulse insulation level (BIL ) rating (for dry-types). Following this convention, the Department developed eight product classes, shown in Table 5.2.1. These product classes were adapted from the National Electrical M anufacturers Association (NEMA)’s TP 1 classification system, although they do not follow the classification system precisely. NEMA’s TP 1 classifies medium-voltage, dry-type distribution transformers into two product classes, < 60 kilovolt (kV) BIL and >60 kV BIL. Based on input f rom manufacturers, the Department elected to increase the differentiation of medium-voltage, dry -type transformers, and create three 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, distribution transformers are further classified by their kilovolt-ampere (kVA) rating. These kVA ratings ar e essentially size categories, indicating the power handling capacity of the transformers. Due t o the construction methods and material properties, efficiency levels vary by both product class and kVA rating. For NEMA’s TP 1-2002, a there are 99 kVA ratings across all the product cla sses (see section 3.7.1). For the Department’s rulemaking, because of the greater degree of differ entiation around the BIL rating in mediumvoltage, dry-type transformers, there are 95 kVA ra tings across all the product classes, as shown in Table 5.2.1.5-2

Table 5.2.1 Product Classes and Number of kVA Rating s

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 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 95

The Department recognized that it would be impracti cal to conduct a detailed engineering analysis of the manufacturer’s selling price-effici ency relationship on all 95 kVA ratings, so it sought to develop an approach that simplified the analysis while retaining reasonable levels of accuracy. The Department consulted with industry r epresentatives and transformer design engineers, and developed an understanding of the co nstruction principles for distribution transformers. It found that many of the units shar e similar designs and construction methods. Thus, the Department simplified the analysis by creating 10 engineering design lines, which group together kVA ratings based on similar principles of design and construction. The 10 design lines subdivide the product classes, to improve the accur acy of the engineering analysis. These 10 engineering design lines differentiate the transformers by insulation type (liquid-immersed or drytype), number of phases (single or three), and prim ary insulation levels for medium-voltage, drytype (three different BIL levels). The Department then selected one unit from each of the engineering design lines for study in the engineering analysis and the life-cycle cost (L CC) analysis (see Chapter 8), reducing the number of units for analysis from 95 to 10. It then extra polated the results of its analysis from the unit studied to the other kVA ratings within that same e ngineering design line. The Department performed this extrapolation in the national impact s analysis (see Chapter 10). The technique used to extrapolate the findings on the representative u nit to the other kVA ratings within a design line i s referred to as “the 0.75 scaling rule.” This rule states that, for similarly designed transformers, c osts of construction and losses scale to the ratio of kV A 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 DOE applied this scaling appears in section 5.2.1 of this chapter. A technical discussion on the derivation of the 0.75 scaling rule appears in Appendix 5B. Table 5.2.2 presents the Department’s 10 design lin es and the representative units selected from each engineering design line for analysis. De scriptions of each of the design lines and the rationale behind the selection of the representativ e units follow Table 5.2.2.5-3

Table 5.2.2 Engineering Design Lines (DLs) and Repre sentative Units for Analysis
PC* DL Type of Distribution

Transformer kVA Range Representative Unit for this

Engineering Design Line

1 1 Liquid-immersed, single-phase,

rectangular tank 10

– 167 50 kVA, 65 / C, single-phase, 60Hz, 14400V primary, 240/120V secondary, rectangular tank
2 Liquid-immersed, single-phase, round tank 10

– 167 25 kVA, 65 / C, single-phase, 60Hz, 14400V primary, 120/240V secondary, round tank 3 Liquid-immersed, single-phase 250

– 833 500 kVA, 65 / C, single-phase, 60Hz, 14400V primary, 277V secondary

2 4 Liquid-immersed, three-phase 15

– 500 150 kVA, 65 / C, three-phase, 60Hz, 12470Y/7200V primary, 208Y/120V secondary 5 Liquid-immersed, three-phase 750

– 2500 1500 kVA, 65 / C, three-phase, 60Hz, 24940GrdY/14400V primary, 408Y/277V secondary

6 9 Dry-type, medium-voltage, threephase, 20-45kV BIL 15

– 500 300 kVA, 150 / C, three-phase, 60Hz, 4160V Delta primary, 480Y/277V secondary, 45kV BIL
10 Dry-type, medium-voltage, threephase, 20-45kV BIL 750

– 2500 1500 kVA, 150 / C, three-phase, 60Hz, 4160V primary, 480Y/277V secondary, 45kV BIL

8 11 Dry-type, medium-voltage, threephase, 46-95kV BIL 15

– 500 300 kVA, 150 / C, three-phase, 60Hz, 12470V primary, 480Y/277V secondary, 95kV BIL
12 Dry-type, medium-voltage, threephase, 46-95kV BIL 750

– 2500 1500 kVA, 150 / C, three-phase, 60Hz, 12470V primary, 480Y/277V secondary, 95kV BIL
10 13 Dry-type, medium-voltage, threephase, 96-150kV BIL 225

– 2500 2000 kVA, 150 / C, three-phase, 60Hz, 12470V primary, 480Y/277V secondary, 125kV BIL * PC means product class (see Chapter 3 of the TSD) . The Department calculated the analytical results for PC5, PC7, and PC9 based on the results for their three-phase counterparts. The Department did not select any re presentative units from the single-phase, medium-voltage product class es (PC5, PC7 and PC9) because of their low sales vo lume. Liquid-immersed transformers are divided into five engineering design lines, based on their tank shape, number of phases, and kVA ratings. The Department believes that this breakdown enables the analysis to identify and capture a more accurate representation of the manufacturer’s selling price and efficiency relationship. Dry-typ e distribution transformers are broken into five engineering design lines, primarily according to th eir BIL levels. The Department believes this level of disaggregation is necessary to capture imp ortant differences in the price-efficiency relationship, particularly as the BIL level varies. For example, a 300 kVA, three-phase, dry-type unit could be classified in design lines 9, 11, or 13, depending on whether the BIL rating is 20-45 kV, 46-95 kV, or 96-150 kV. For design lines 9 through 13, the representative u nits selected for some of the dry-type design lines may not be the standard BIL levels ass ociated 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 minimum efficiency standard woul d not excessively penalize customers purchasing transformers at higher BIL ratings withi n the range. For example, a 300 kVA with a 4160V primary is called a “5kV class” transformer and would normally be built with a 30kV BIL level. However, customers may also choose to order this transformer with 45kV BIL or 60kV BIL. If the candidate minimum efficiency standard were s et based on a 30kV BIL, it may not be possible to achieve that same efficiency rating for customer s ordering 60kV BIL. Thus, the Department evaluated the middle BIL level (in this example, 45 kV BIL), making it slightly easier to comply for a lower BIL, and not too difficult (or impossible) for the higher BIL.5-4

The remainder of this section discusses each of the ten engineering design lines, providing a description and explanation of the transformers cov ered. Design Line 1 . This is the basic, high-volume line for rectangu lar-tank, single-phase, liquidimmersed distribution transformers, ranging from 10 kVA to 167 kVA. Transformers in this design line typically have BIL levels ranging from 30 kV t o 150 kV and a tap configuration of four 21⁄2 percent taps—two above and two below the nominal vo ltage. Tap configurations enable transformer users to maintain full (rated) output v oltage by slightly increasing or decreasing the number of turns in the primary in anticipation of an input voltage slightly above or below the rated nominal. This design line has a primary voltage le ss than 35 kV, and a secondary voltage less than or equal to 600 Volts (V). The representative unit selected for design line 1 is a 50 kVA pad-mounted unit, as this is a high shipment volume rating, and is approximately t he middle of the kVA range for this design line (10 kVA, 15 kVA, 25 kVA, 37.5 kVA, 50 kVA, 75 kVA, 100 kVA, and 167 kVA). Engineering design considerations and manufacturing differences led to the placement of 250 kVA and higherrated units in design line 3. Design Line 2 . This is the basic, high-volume line for round-tank (pole mounted), singlephase, liquid-immersed distribution transformers, r anging from 10 kVA to 167 kVA . Although some manufacturers tend to employ the same basic co re/coil design for design line 1 and design line 2, others may have design differences between pad-m ounted and pole-mounted transformers. The Department decided to analyze these two types of di stribution transformers separately for the engineering and LCC analyses. Transformers in this design line typically have BIL levels ranging from 30 kV and 150 kV, a tap configuration of four 21⁄2 percent taps—two above and two below the nominal, a primary voltage less than 35 kV, and a s econdary voltage less than or equal to 600 V. The representative unit selected for design line 2 is a 25 kVA pole-mounted unit, as this is a high-volume rating for pole-mounted transformers, and is on the lower end of the kVA range for this design line (10 kVA, 15 kVA, 25 kVA, 37.5 kVA, 50 kVA, 75 kVA, 100 kVA, and 167 kVA). Engineering design considerations and manufacturing differences led to the placement of 250 kVA and higher-rated units in design line 3. Design Line 3 . This design line groups together single-phase, r ound-tank, liquid-immersed distribution transformers, ranging from 250 kVA to 833 kVA. Together, design lines 1 through 3 cover all the single-phase, liquid-immersed units ( there are no standard kVA ratings between 167 and 250 kVA). Transformers in this design line typ ically have BIL levels ranging from 30 kV to 150 kV, a tap configuration of four 21⁄2 percent taps —two above and two below the nominal, a primary voltage less than 35 kV, and a secondary vo ltage less than or equal to 600 V. The representative unit selected for design line 3 is a 500 kVA round-tank, as this is a common rating and occurs in the middle of the kVA r ange for this design line (250 kVA, 333 kVA, 500 kVA, 667 kVA, and 833 kVA). Although high curr ents result with 277 V secondary at the larger kVA ratings, high-current bushings are avail able, and a market does exist for these transformers. Design Line 4 . Design line 4 represents rectangular tank, three -phase, liquid-immersed distribution transformers, ranging from 15 kVA to 5 00 kVA. Transformers in this design line5-5

typically have BIL levels ranging from 30 kV to 150 kV, a tap configuration of four 21⁄2 percent taps—two above and two below the nominal, a primary voltage less than 35 kV, and a secondary voltage less than or equal to 600 V. The representative unit selected for design line 4 is a 150 kVA transformer, as this is a common rating in this design line and occurs approx imately in the middle of the kVA range (15 kVA, 30 kVA, 45 kVA, 75 kVA, 112.5 kVA, 150 kVA, 22 5 kVA, 300 kVA, and 500 kVA). Design Line 5 . Design line 5 represents rectangular tank, three -phase, liquid-immersed distribution transformers, ranging from 750 kVA to 2500 kVA. Together, design lines 4 and 5 cover all the three-phase, liquid-immersed units (t here are no standard kVA ratings between 500 and 750 kVA). Transformers in this design line typical ly have BIL levels ranging from 95 kV to 150 kV, a tap configuration of four 21⁄2 percent taps—two above and two below the nominal, a primary voltage less than 35 kV, and a secondary voltage le ss than or equal to 600 V. The representative unit selected for this design li ne 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 kV A). Design Line 9 . Design line 9 represents three-phase, medium-vol tage, ventilated dry-type distribution transformers, ranging from 15 kVA to 5 00 kVA. To accommodate the broad kVA range and to allow for engineering differences in c onstruction principles and associated costs, the Department split the three-phase, medium-voltage, dry-type units into design lines 9 and 10. Transformers in this design line typically have pri mary voltages less than or equal to 5 kV with a BIL rating between 20 kV and 45 kV. The secondary voltage is less than or equal to 600 V and the tap arrangement is typically four 21⁄2 percent taps, two above and two below the nominal. The representative unit selected for design line 9 is 300 kVA, as this is a common rating in this size range, and occurs near the high end of th e kVA ratings for this design line (15 kVA, 30 kVA, 45 kVA, 75 kVA, 112.5 kVA, 150 kVA, 225 kVA, 3 00 kVA, and 500 kVA). Design Line 10 . Design line 10 represents three-phase, medium-vo ltage, ventilated dry-type distribution transformers, ranging from 750 kVA to 2500 kVA. Transformers in this design line typically have primary voltages less than or equal to 5 kV with a BIL rating between 20 kV and 45 kV. The secondary voltage is less than or equal to 600 V and the tap arrangement is typically four 21⁄2 percent taps, two above and two below the nomina l. The representative unit selected for this design li ne is a 1500 kVA transformer, as this is a common rating, 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 11 . Design line 11 represents three-phase, medium-vo ltage, ventilated dry-type distribution transformers, ranging from 15 kVA to 5 00 kVA. This design line parallels design line 9, with a higher primary insulation level, 46 kV to 95 kV BIL. Because dry-type transformer designs and, more importantly, the efficiency of th ose designs, are strongly influenced by changes in BIL, the Department considered these higher BIL rat ings separately. The typical tap arrangement is four 21⁄2 percent taps, two above and two below the n ominal. The primary voltage is typically less than or equal to 15 kV and the secondary voltage is less than or equal to 600 V.5-6

The kVA ratings in design line 11 are 15 kVA, 30 kV A, 45 kVA, 75 kVA, 112.5 kVA, 150 kVA, 225 kVA, 300 kVA, and 500 kVA. The shipments for this design line are primarily in the kVA range inclusive of and between 225 kVA and 500 kVA; therefore, the Department selected the 300 kVA rating as the representative unit for analy sis. Design Line 12 . Design line 12 represents three-phase, medium-vo ltage, ventilated dry-type distribution transformers, ranging from 750 kVA to 2500 kVA. This design line parallels design line 10, with a higher primary insulation level, 46 kV to 95 kV BIL. The typical tap arrangement is four 21⁄2 percent taps, two above and two below the n ominal. The primary voltage is typically 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 design li ne is a 1500 kVA transformer, as it is a common rating in this size range and BIL rating, an d it occurs in the middle of the kVA range covered by this design line (750 kVA, 1000 kVA, 150 0 kVA, 2000 kVA, and 2500 kVA). Design Line 13 . As a further extension on the dry-type, three-ph ase, medium-voltage BIL ranges, the Department analyzed 96 kV to 150 kV BIL , in a design line ranging from 225 kVA to 2500 kVA. The 225 kVA rating is considered to be t he lowest kVA rating where one would expect to see a unit with a BIL greater than 110 kV. The typical tap arrangement is four 21⁄2 percent taps, two above and two below the nominal. The primary v oltage is typically less than or equal to 35 kV and the secondary voltage is less than or equal to 600 V. This third set of dry-type, three-phase, medium-vol tage 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 represen tative unit selected for design line 13 is a 2000 kVA transformer. This unit is a common rating in t his size range, and 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). In addition to the three product classes for dry-ty pe, medium-voltage, three-phase distribution transformers (for which there are five engineering design lines) presented in Table 5.2.1, there are three product classes for single-p hase, dry-type, medium-voltage units. As discussed in Chapter 3, the shipment volume for single-phase, dry-type, medium voltage transformers is very low, and thus it does not warrant the level of effo rt involved in conducting analysis on these specifi c units. The Department decided instead to scale the analysis findings from three-phase units to the single-phase units by dividing by three. In this w ay, the Department was able to concentrate resources and improve the accuracy in other, higher volume and more important distribution transformer product classes.

5.2.1 Summary of Design Line Coverage The following four tables summarize the coverage of each of the design lines in relation to the various product classes and kVA ratings. The a bbreviation DL stands for design line, and the row in the table where the phrase “Rep Unit” appear s indicates the kVA rating of the representative unit from that design line. For example, DL 1 stan ds for design line 1, spanning from 10 to 167 kVA liquid-type, single-phase. The label “Rep Unit ” appears in row 50 kVA, indicating that the 505-7 Product Class 1 Liquid-Immersed, Single-Phase 

### Product Class 2 Liquid-Immersed, Three-Phase
kVA Rectang.

Tank Round

Tank 

### kVA Design 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 2500DL 1DL 2DL 3 Rep Unit

Rep UnitDL 4 Rep UnitDL 5 Rep Unit Rep Unit kVA is the representative unit for DL 1. Similarly , the representative unit for DL 2 is the 25 kVA unit. There are five liquid-immersed design lines, three single-phase and two three-phase, as shown in Table 5.2.3. To capture any design differ ences between a single-phase pole and a padmounted transformer, the Department analyzed units in both DL 1 and DL 2, spanning the same kVA ratings (10 kVA to 167 kVA). On the three-phas e liquid-immersed side, there is no overlap between those two design lines.

Table 5.2.3 Liquid-Immersed Design Lines and Represe ntative Units

Table 5.2.4 presents product classes (abbreviated “ PC”) for medium-voltage, single-phase, dry-type units. As discussed in section 3.4, Natio nal Shipment Estimate, these units have an extremely low shipment volume. All three product c lasses shown in Table 5.2.4 together represent less than one-third of one percent of dry-type ship ments on both a per-unit and an MVA-capacity basis. Thus, the Department did not consider it ap propriate to conduct analysis of any units from these three product classes. As an alternative to investing time and resources analyzing these low-volume units, the Department used the results from the medium-voltage , three-phase dry-type units (presented in Table 5.2.6) and divided those findings by three, c reating virtual (calculated) representative units (labeled as “Virtual RU” in the table) for these th ree product classes. The Department used the representative units from design lines 9, 10, 11, 1 2, and 13. These virtual representative units are shown in their respective rows, following the appli cation of the quotient. For example, in the single5-8 

### Dry-Type, Medium-Voltage, Single-Phase


### kVA PC 5*

Low BIL 20-45kV PC 7

Med BIL 46-95kV PC 9

High BIL > 96kV 15 - 25 - 37.5 - 50 - 75 100 167 250 333 500 667 833DL9 / 3

Virtual RUDL11 / 3

Virtual RUDL13 / 3

Virtual RU Virtual RUDL10 / 3 Virtual RUDL12 / 3 phase (20–45kV BIL) column, the representative unit from DL 9 is a three-phase 300 kVA unit, so it scales to a single-phase, 100 kVA unit in Table 5.2.4. Table 5.2.4 Dry-Type, Medium-Voltage, Single-Phase D esign Lines

Table 5.2.5 presents the product classes for the me dium-voltage, three-phase, dry-type distribution transformers and each of the design li nes 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 (DL 13) covers all the ratings from 225kVA to 2500kVA. Within DL 13, the Department did not extrapolate the results of this unit to ratings low er than 150kVA because there were no shipments at these ratings in the shipments analysis and it is v ery unlikely that they would be built.5-9 Dry-Type, Medium-Voltage, Three-Phase 

### kVA PC 6

Low BIL 20-45kV PC 8

Med BIL 46-95kV PC 10

High BIL > 96kV 15 - 30 - 45 - 75 - 112.5 - 150 - 225 300 500 750 1000 1500 2000 2500DL 9DL 11DL 13

Rep Unit Rep UnitDL 10DL 12 Rep Unit Rep Unit Rep Unit Table 5.2.5 Dry-Type, Medium-Voltage, Three-Phase De sign Lines

5.2.2 Scaling Relationships in Transformer Manufactu ring The Department simplified the engineering analysis by creating design lines, selecting representative units from these design lines, and s caling the results of the analysis on these representative units within their respective designlines. This section briefly introduces the scalin g relationship the Department used to extrapolate the findings on the representative units to the other kVA ratings. A more detailed discussion of the der ivation of the 0.75 scaling rule is provided in Appendix 5B. The scaling formulae are mathematical relationships that exist between the kVA ratings and the physical size, cost, and performance of transfo rmers. The size-versus-performance relationships arise from fundamental equations describing a trans former's voltage and kVA rating. For example, when the kVA rating, voltage, and frequency are fix ed, the product of the conductor current density, core flux density, core cross-sectional area, and t otal conductor cross-sectional area is constant. To illustrate this point, consider a transformer wi th four fixed variables: frequency, magnetic flux density, current density, and BIL rat ing. If one enlarges (or decreases) the kVA rating, then the only parameters free to vary are t he core cross-section and the core window area through which the windings pass. Thus, to increase (or decrease) the kVA rating, the dimensions for height, width, and depth of the core/coil assem bly scale equally in all directions. Analysis of t his scaling relationship reveals that each of the linear dimensions varies as the ratio of kVA ratings to the 1⁄4 power. Similarly, areas vary as the ratios o f 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." Application of the 0.75 scaling rule assumes that the efficienc y profile of a given transformer will have the same5-10

shape as the transformer being scaled. Table 5.2.6 depicts the most common scaling relationships in transformers.

Table 5.2.6 Common Scaling Relationships in Transfor mers

Parameter Being Scaled Relationship 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 (liquid-immersed or dry-type, s ingle-phase or three-phase), the primary voltage, the core configuration, the core material, the core flux density, and the current density (amperes per square inch of conductor cross-section) in both the primary and secondary windings are all held constant: 1. The physical proportions are constant (same rela tive 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 magni tude in both directions (e.g., from 50 kVA to 5 kVA or from 50 kVA to 500 kVA), the scaling rules s hown in Table 5.2.6 can be used to establish reasonable estimates of performance, dimensions, co sts, and losses. In practice, these rules can be applied over even wider ranges to estimate general performance levels. The Department’s application of the 0.75 scaling rule in this analys is is always less than an order of magnitude. To illustrate how the scaling laws are used, consid er 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,”5-11 NL 0 = no-load losses of transformer “0,” 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 algebraica lly to show that the load loss also varies to the 0.75 power. Starting with the concept that total losses equals 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”

Inserting 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 applied to estim ate the losses of a transformer, given the losses and kVA rating of a reference (analyzed) uni t. However, in order for this rule to be applicable, the transformer type must be the same, 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. Additionally, use of the 0 .75 scaling rule assumes that the efficiency profile of a given transformer will have the same s hape as the transformer being scaled. A detailed discussion on the derivation of the 0.75 scaling ru le is provided in Appendix 5B. The Department used the 0.75 scaling rule to scale the analysis findings on each of the representative units within the 10 design lines to the 85 kVA ratings that were not analyzed. The Department applied the scaling rule within the desi gn lines in the national impact analysis (Chapter 10), where it calculated efficiency ratings for the 85 kVA ratings not analyzed.

5.3 TECHNICAL DESIGN INPUTS For all ten representative units, the engineering analysis explored the relationship between the manufacturer selling prices and corresponding t ransformer efficiencies. For this analysis, the Department contracted Optimized Program Service, In c. (OPS) in Ohio, a software company specializing in transformer design since 1969. Usi ng a range of input parameters and material prices, the OPS software produces a design. This d esign has specific information about the core and coil, including physical characteristics, dimension s, material requirements and mechanical clearances, as well as a complete electrical analys is of the final design. This optimized, practical transformer design, the bill of materials, and an e lectrical analysis report contain sufficient information for a manufacturer to build the unit. The software’s output is used to generate an estimated cost of manufacturing materials and labor , which is then converted to a manufacturer selling price by applying markups. The electrical analysis report estimates the perfor mance of the transformer design (including efficiency) at 25 percent, 35 percent, 50 percent, 65 percent, 75 percent, 100 percent, 125 percent, and 150 percent of nameplate load. The software ou tput provides a clear understanding of the relationship between cost and efficiency because it provides detailed data on design variances, as well as a bill of materials, labor costs, and effic iency. The software does not capture retooling cos ts associated with changing production designs for a s pecific manufacturer. In some cases, however, the Department captured tooling costs associated wi th manufacturing mitered cores by applying adders to the steel price. One of the inputs to the design software consisted of a range of what are known in the industry as A and B evaluation combinations (see se ction 3.6, Total Ownership Cost Evaluation). The combination of A and B input to the design soft ware mimics a distribution transformer purchase order. The A parameter represents a custo mer's present value of future losses in the transformer core (no-load losses). The B value rep resents a customer's present value of future losses in the windings (load losses). The B parameter is never larger than A, as this would imply a specification for a transformer whose average load would be more than 100 percent of the nameplate load. The A and B values take into accou nt a range of factors that usually vary from customer to customer.5-13

The A and B values are expressed in terms of dollar s per watt of loss. The greater the values of A and B, the greater the importance a customer a ttaches to the value of future transformer losses. As A and B values increase, the customer places gre ater importance on reducing the watts of core and winding losses, respectively, and so the custom er chooses a more energy-efficient transformer. The Department used broad ranging combinations of A and B evaluation formulae (presented in Table 5.3.1 and Table 5.3.2) to creat e a complete set of efficiency levels for each design option combination analyzed. The efficiency levels spanned from a low-first-cost unit to a maximum technologically feasible (“max-tech”) desig n. For the low-first-cost design, the A and B evaluation values were both $0/watt, indicating tha t the customer does not attach any financial value to future losses in the core or coil of the transfo rmer. For the maximum technologically feasible design, the A and B evaluation values were very hig h, pushing the software to design at the highest efficiencies achievable. The Department created its combinations of A and B evaluation formulae combining two techniques to ensure there were sufficient designs in the database for the analysis. The first technique was to create, as in the advance notice o f proposed rulemaking (ANOPR), a ‘grid’ of A and B combinations. The ‘grid’ technique involved increasing the value of A by a step value, and then increasing the B value from zero to that value of A, using a different step value. Thus, if A ha d incremental steps of $0.25 and B had steps of $0.20 , the combinations would work as follows: ($0.00, $0.00), ($0.25, $0.00), ($0.25, $0.20), ($0 .50, $0.00), ($0.50, $0.20), ($0.50, $0.40), ($0.75 , $0.00), and so on. Table 5.3.1 presents the ranges and incremental steps for the A and B combinations used in the three grids. Table 5.3.1 A and B Grid Combinations used by Softwa re to Generate Design Database Grid Number A values

and increments B values and increments Resultant # of (A, B) combinations 1 $0 to $2 by 0.25 steps $0 to $2 by 0.20 steps 47 2 $2.50 to $8 by 0.50 steps $0 to $8 by 0.40 steps 157 3 $9 to $16 by 1.00 steps $3 to $8 by 0.50 steps 85 The second technique for generating A and B evaluat ion formulae in the engineering analysis was new for the notice of proposed rulemak ing (NOPR). The Department understands that the ratio of A to B represents an implicit loading for the transformer. Therefore, the Department created a set of (A, B) values in which the B is ca lculated from the A. The B term is calculated as the A times the percent load squared. In other wor ds, if A equals $1 and DOE is interested in calculating the appropriate B for a 50 percent root -mean-square (RMS) load, then it would be $1 times (0.50)^2, or $0.25. Thus, the combination of ($1.00, $0.25) represents approximately a 50 percent RMS load. As with the “grid,” the A values increased with a step function, and B values were calculated as fractions of A so that the ratio of A to B encompassed the RMS loading points that were identified in the Department’s loading an alysis (i.e., 35 percent and 50 percent). Calling this approach the “fan,” DOE calculated the B value s for each A at the following RMS loading points: 5 percent, 10 percent, 15 percent, 20 perc ent, 25 percent, 30 percent, 35 percent, 40 percent , 45 percent, 50 percent, 55 percent, and 60 percent. Table 5.3.2 presents the range of the two fan combinations used in the NOPR.5-14

Figure 5.3.1 A and B Combination Software Inputs use d in the Engineering Analysis Table 5.3.2 A and B Fan Combinations used by Softwar e to Generate Design Database Fan Number A values

and increments B values and increments Resultant # of (A,B) combinations 1 $0 to $2 by 0.50 steps 5% to 60% implicit loading b y 5% steps 47 2 $3 to $16 by 1.00 steps 5% to 60% implicit loading by 5% steps 182
When used together, these two techniques created a broad spectrum of A and B combinations as inputs to the OPS software. Figure 5.3.1 illustrates the coverage of designs for the 518 A and B combinations.

Occasionally, the design software generated the sam e transformer design for two different A and B combinations, creating duplicate designs in t he engineering analysis database. Later, in the LCC analysis, the Department removed any duplicate designs from the engineering database. 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 configurations (shell or core-type). Within each of the design lines discussed in the se ctions 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 dec isions on how to manufacture a given transformer5-15

using different core configurations, core steels, and winding materials. To capture this variation in designs, DOE analyzed the 10 representative units u sing 5–11 different design option combinations of core type, core steel, and winding material. As discussed in the technology assessment (see Chapter 3), core steel is produced in a range of qu alities (from an efficiency perspective). M2 core steel is oriented grain silicon steel and has thin laminations, and consequently has very low losses. M43 core steel is non-oriented grain silicon steel and is rolled in much thicker laminations, thus contributing to higher core losses. Table 5.3.3 li sts 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 stee l are given as a function of the magnetic flux density, measured in Tesla.
Table 5.3.3 Core Steel Grades, Thicknesses and Assoc iated 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 s ilicon 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

M5 0.012 0.53 Watts/lb at 1.5 T 0.83 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 siliconsteel

H-0 DR 0.009 0.60 Watts/lb at 1.7 T “Domain-refined, 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 co mparable at the same magnetic flux density (measure d in Tesla) In addition to selecting a core steel, the manufact urer’s selection of a core design may also contribute to the overall efficiency of a transform er. A transformer facility may be optimized to work around one or two core configurations. Table 5.3.4 provides a list of all the core configurations used for each of the 10 design lines . The Department selected these configurations, in combinations with the range of core steels and w inding materials, to represent the most common construction methods for these kVA ratings in the U S market. Note that, for design lines 2, 3, and 9, the Department analyzed two different core const ruction configurations.5-16

Table 5.3.4 Core Configurations Used in Each Design Line Design Line # Phases Core Configurations Used in the Engineering Analysis DL 1 1 Wound core - distributed gap, shell-type DL 2 1 Wound core - distributed gap, shell-type or co re-type DL 3 1 Wound core - distributed gap, shell-type or co re-type DL 4 3 Wound core - distributed gap, 5-leg DL 5 3 Wound core - distributed gap, 5-leg DL 9 3 Stacked, butt-lap or mitered joint, 3-leg DL 10 3 Stacked, cruciform, mitered joint, 3-leg DL 11 3 Stacked, mitered joint, 3-leg DL 12 3 Stacked, cruciform, mitered joint, 3-leg DL 13 3 Stacked, cruciform, mitered joint, 3-leg
For the single-phase representative units, the conf igurations used are either core-type or shell-type. This applies whether the core consists of stacked or wound laminations of core steel. For wound cores, manufacturers generally employ a t echnique known as ‘distributed gap.’ This means that each lamination of core steel wound arou nd the form will have a start and finish point (the ‘gap’), staggered with respect to the laminati ons on either side. Distributed gap core construction techniques are used to minimize the pe rformance impact of the lamination joint gaps (reducing the exciting current) and, by locating in side the coil window, reduce the transformer’s operating sound level. Figure 5.3.2 illustrates th e two types of single-phase core configurations.

Three-phase transformers can have three-legged, fou r-legged, five-legged, or Evans cores. In the engineering analysis, the Department conside red the three-legged construction techniques for the three-phase dry-types and five-legged construct ion for the three-phase liquid-immersed transformers. Figure 5.3.3 below illustrates the d ifference between the three-legged and the fivelegged core construction techniques. A three-legge d core is assembled from stacked laminations, the joints of which can be butt-lapped or mitered. Where there is an economic need to reduce core losses, particularly in keeping with the use of mor e efficient grades of core steel (M2 or M3), the mitered core tends to be selected. The Department recognizes that there are a variety of approaches to mitered core construction: “scrapless T-miterin g,” “full-mitering,” and “step-mitering.” The Department modeled full-mitered cores.

Figure 5.3.2 Graphic of Single-Phase Core Configurat ions5-17

For larger kVA ratings, design economics may cause the selection of a cruciform core section, where multiple lamination widths are stack ed in increasing and then decreasing widths to create a circular core form (or “log”) around which the windings are placed. Figure 5.3.4 illustrates the cruciform core by showing a cross-section. Thi s figure shows four different widths of steel being used, but there can be fewer or more widths, depending on the design. By using a core configuration that better follows the contours of t he windings, losses are again reduced, resulting in a more efficient transformer. The use of the three -legged core usually depends on the primary winding being delta-connected. If the primary wind ing is wye-connected, as is frequently the case for pad-mounted transformers used in underground di stribution, the core configuration needs to be four-legged or five-legged.

The five-legged core is assembled from four wound-c ore loops, and is the common configuration for liquid-filled, three-phase distri bution 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 exp lained for single-phase, wound-core transformers.

Figure 5.3.3 Graphic of Three-phase Core Configurati ons

Figure 5.3.4 C r u c i f o r m C o r e

Cross-Section5-18

5.3.1 Design Line 1 Representative Unit Design line 1 (DL 1) represents rectangular-tank, l iquid-immersed, single-phase distribution transformers, ranging from 10 kVA to 167 kVA. The representative unit selected for this design line is a 50kVA pad-mounted unit. The following ar e the technical specifications that constitute input parameters to the OPS design software: KVA: 50 (liquid-immersed, rectangular-tank) Primary: 14400 Volts at 60 Hz Secondary: 240/120V T Rise: 65 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi-Lo (Shell-Type) Core: Wound core - distributed gap Taps: Four 21⁄2 percent, two above and two below the nominal Impedance Range: 1.0–3.5 percent For DL 1, DOE selected eight construction combinati ons (called “design option combinations”), based on input from manufacturers and other technical experts. The core selected was shell-type, because the application is for a pa d-mounted unit, and this shape is well suited to a rectangular tank. With the exception of the max te ch/high efficiency designs, DOE selected eight design option combinations to represent the most co mmon construction practices for this representative unit. Table 5.3.5 Design Option Combinations for the Repre sentative Unit from Design Line 1 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type
M6 Al (wire) Al (strip) Shell - DG* Wound Core M6 Cu (wire) Al (strip) Shell - DG Wound Core M3 Al (wire) Al (strip) Shell - DG Wound Core M3 Cu (wire) Al (strip) Shell - DG Wound Core M2 Cu (wire) Al (strip) Shell - DG Wound Core M2 Cu (wire) Cu (strip) Shell - DG Wound Core ZDMH Cu (wire) Cu (strip) Shell - DG Wound Core SA1 (Amorphous) Cu (wire) Cu (strip) Shell - DG Wound Core *DG - Distributed gap wound core construction, wher e the core laminations are wound in such a way that the gap between the start and finish of a lamination is sta ggered in the cross-section of the core. The Department analyzed each of the eight design op tion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, creating 4,144 designs.5-19

5.3.2 Design Line 2 Representative Unit Design line 2 (DL 2) represents round-tank, liquid- immersed, single-phase distribution transformers, ranging from 10 kVA to 167 kVA. The representative unit selected for this design line is a 25kVA pole-mounted unit. The following are the technical specifications that constitute input parameters to the OPS design software: KVA: 25 (liquid-immersed, round-tank) Primary: 14400 Volts at 60 Hz (125 kV BIL) Secondary: 120/240V T Rise: 65 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi-Lo (Shell-Type), Lo-Hi (Core-Type, for amorphous core) Core: Wound core - distributed gap Taps: Four 21⁄2 percent, two above and two below th e nominal Impedance Range: 1.0–3.5 percent For DL 2, DOE selected 10 design option combination s, based on input from manufacturers and other technical experts. With the exception of the max tech/high-efficiency designs, DOE selected these design option combinations to repres ent the most common construction practices for the representative unit. Table 5.3.6 Design Option Combinations for the Repre sentative Unit from Design Line 2 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type
M6 Al (wire) Al (strip) Shell - DG Wound Core M6 Cu (wire) Al (strip) Shell - DG Wound Core M4 Al (wire) Al (strip) Shell - DG Wound Core M4 Cu (wire) Al (strip) Shell - DG Wound Core M3 Cu (wire) Al (strip) Shell - DG Wound Core M3 Cu (wire) Cu (strip) Shell - DG Wound Core M2 Cu (wire) Al (strip) Shell - DG Wound Core M2 Cu (wire) Cu (strip) Shell - DG Wound Core ZDMH Cu (wire) Cu (strip) Shell - DG Wound Core SA1 (Amorphous) Cu (wire) Cu (strip) Core - DG Wound Core
The Department analyzed each of the 10 design optio n combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, c reating 5,180 designs.5-20

5.3.3 Design Line 3 Representative Unit Design line 3 (DL 3) represents round-tank, liquid- immersed, single-phase distribution transformers, ranging from 250 kVA to 833 kVA. The representative unit selected for this design line is a 500kVA round-tank transformer. The follo wing are the technical specifications which constitute input parameters to the OPS design softw are: KVA: 500 (liquid-immersed, round-tank) Primary: 14400 Volts at 60 HZ (150kV BIL) Secondary: 277 Volts T Rise: 65 

### / C Ambient: 20 

### / C Winding Configuration: Lo-Hi-Lo (Shell-Type), Lo-Hi (Core-Type, for amorphous core) Core: Wound core - distributed gap Taps: Four 21⁄2 percent, two above and two below th e nominal Impedance Range: 2.5–5.75 percent For DL 3, the Department selected seven design opti on combinations of core steel and winding material, based on input from manufacturers and other technical experts. With the exception of the max tech/high-efficiency designs, DOE chose design option combinations to represent the most common construction practice for this representative unit. Table 5.3.7 Design Option Combinations for the Repre sentative Unit from Design Line 3 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type

M6 Al (wire) Al (strip) Shell - DG Wound Core M4 Cu (wire) Al (strip) Shell - DG Wound Core M3 Cu (wire) Al (strip) Shell - DG Wound Core M2 Cu (wire) Al (strip) Shell - DG Wound Core M2 Cu (wire) Cu (strip) Shell - DG Wound Core ZDMH Cu (wire) Cu (strip) Shell - DG Wound Core SA1 (Amorphous) Cu (wire) Cu (strip) Core- DG Wound Co re The Department analyzed each of the seven design op tion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, creating 3,626 designs. 5.3.4 Design Line 4 Representative Unit Design line 4 (DL 4) represents rectangular tank, l iquid-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 th e technical specifications that constitute input parameters to the OPS design software: KVA: 150 (liquid-immersed, pad mount)5-21

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 F eed Winding Configuration: Lo-Hi (Core-Type) Core: Wound core - distributed gap, 5-leg Taps: Four 21⁄2 percent, two above and two below th e nominal Impedance Range: 1.5–3.0 percent For DL 4, DOE selected seven design option combinat ions of core steel and winding types based on input from manufacturers and other technic al experts. With the exception of the max tech/high efficiency designs, DOE selected these de sign option combinations to represent the most common construction practice for the representative unit. Table 5.3.8 Design Option Combinations for the Repre sentative Unit from Design Line 4 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type

M6 Al (wire) Al (strip) 5-Leg DG Core M4 Al (wire) Al (strip) 5-Leg DG Core M3 Cu (wire) Al (strip) 5-Leg DG Core M2 Cu (wire) Al (strip) 5-Leg DG Core M2 Cu (wire) Cu (strip) 5-Leg DG Core ZDMH-price 1 Cu (wire) Cu (strip) 5-Leg DG Core SA1 (Amorphous) Cu (wire) Cu (strip) 5-Leg DG Core
The Department analyzed each of the seven design op tion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, creating 3,626 designs. 5.3.5 Design Line 5 Representative Unit Design line 5 (DL 5) represents rectangular tank, l iquid-immersed, three-phase distribution transformers, ranging from 750 kVA to 2500 kVA. Th e representative unit selected for this design line is a 1500kVA transformer. The following are t he technical specifications that constitute input parameters to the OPS 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 F eed Winding Configuration: Lo-Hi (Core-Type) Core: Wound core - distributed gap, 5-leg5-22

Taps: Four 21⁄2 percent, two above and two below the nominal Impedance Range: 4.5-7.0 percent For DL 5, the Department selected seven design opti on combinations of core steel and winding material, based on input from manufacturers and 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 practices for the representative unit. Table 5.3.9 Design Option Combinations for the Repre sentative Unit from Design Line 5 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type

M4 Al (wire) Al (strip) 5-Leg DG Core M4 Cu (wire) Al (strip) 5-Leg DG Core M3 Cu (wire) Al (strip) 5-Leg DG Core M2 Cu (wire) Al (strip) 5-Leg DG Core M2 Cu (wire) Cu (strip) 5-Leg DG Core ZDMH Cu (wire) Cu (strip) 5-Leg DG Core SA1 (Amorphous) Cu (wire) Cu (strip) 5-Leg DG Core
The Department analyzed each of the seven design op tion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, creating 3,626 designs.

5.3.6 Design Line 9 Representative Unit Design line 9 (DL 9) represents ventilated dry-type , three-phase, medium-voltage distribution transformers with a 20–45kV BIL, rangi ng from 15 kVA to 500 kVA. The representative unit selected for this design line i s a 300 kVA transformer. The following are the technical specifications that constitute input parameters to the OPS 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-Hi Core: Stacked, butt-lap; Stacked, mitered Taps: Four 21⁄2 percent, two above and two below the nominal Impedance Range: 3.0–6.0 percent For DL 9, the Department selected five design optio n combinations of core steel and winding material, based on input from manufacturers and other technical experts. With the5-23

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 for the Repr esentative Unit from Design Line 9 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type
M6, 29 gauge Al (wire) Al (wire) 3-Leg Stacked Buttlap M6, 29 gauge Cu (wire) Cu (wire) 3-Leg Stacked Full M iter** M5 Al (wire) Al (wire) 3-Leg Stacked Full Miter M3 Cu (wire) Al (strip) 3-Leg Stacked Full Miter H-O DR* Cu (wire) Cu (strip) 3-Leg Stacked Full Miter * H-O DR is a domain-refined, high permeability cor e steel, and represents the max tech for dry-type u nits. ** Full Miters are not step-miters, but are miteredjoints for all three legs. These cores are stacke d three by three. The Department analyzed each of the five design opt ion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, c reating 2,590 designs. 5.3.7 Design Line 10 Representative Unit Design line 10 (DL 10) represents dry-type, three-p hase, 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 transfo rmer. The following are the technical specifications that constitute input parameters to the OPS 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, cruciform, mitered joint Taps: Four 21⁄2 percent, two above and two below the nominal Impedance Range: 4.0-6.0 percent For DL 10, the Department selected five design opti on combinations of core steel and winding material, based on input from manufacturers and 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.5-24

Table 5.3.11 Design Option Combinations for the Repr esentative Unit from Design Line 10 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type

M6 Al (wire) Al (strip) 3-Leg Mitered Cruciform M6 Cu (wire) Cu (strip) 3-Leg Mitered Cruciform M4 Cu (wire) Al (strip) 3-Leg Mitered Cruciform M3 Cu (wire) Cu (strip) 3-Leg Mitered Cruciform H-O DR* Cu (wire) Cu (strip) 3-Leg Mitered Cruciform * H-O DR is a domain-refined, high permeability cor e steel, and represents the max tech for dry-type u nits. The Department analyzed each of the five design opt ion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, c reating 2,590 designs. 5.3.8 Design Line 11 Representative Unit Design line 11 (DL 11) represents dry-type, three-p hase, medium-voltage distribution transformers with a 46–95kV BIL, ranging from 15 kV A to 500 kVA. The representative unit selected for this design line is a 300 kVA transfor mer. The following are the technical specifications that constitute input parameters to the OPS 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 the nominal Impedance Range: 3.0-7.0 percent For DL 11, the Department selected five design opt ion combinations of core steel and winding material, based on input from manufacturers and 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.5-25

Table 5.3.12 Design Option Combinations for the Repr esentative Unit from Design Line 11 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type

M6 Al (wire) Al (strip) 3-Leg Stacked Full Miter** M6 Cu (wire) Cu (strip) 3-Leg Stacked Full Miter M4 Cu (wire) Al (strip) 3-Leg Stacked Full Miter M3 Cu (wire) Cu (strip) 3-Leg Stacked Full Miter H-O DR* Cu (wire) Cu (strip) 3-Leg Stacked Full Miter * H-O DR is a domain-refined, high permeability cor e steel, and represents the max tech for dry-type u nits. ** Full Miters are not step-miters, but are miteredjoints for all three legs. These cores are stacke d three by three. The Department analyzed each of the five design opt ion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, c reating 2,590 designs.

5.3.9 Design Line 12 Representative Unit Design line 12 (DL 12) represents dry-type, three-p hase, 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 transfo rmer. The following are the technical specifications that constitute input parameters to the OPS 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 the nominal Impedance Range: 4.0–7.0 percent For DL 12, the Department selected five design opti on combinations of core steel and winding material, based on input from manufacturers and 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.5-26

Table 5.3.13 Design Option Combinations for the Repr esentative Unit from Design Line 12 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type

M6 Al (wire) Al (strip) 3-Leg Mitered Cruciform M6 Cu (wire) Cu (strip) 3-Leg Mitered Cruciform M4 Cu (wire) Al (strip) 3-Leg Mitered Cruciform M3 Cu (wire) Cu (strip) 3-Leg Mitered Cruciform H-O DR* Cu (wire) Cu (strip) 3-Leg Mitered Cruciform * H-O DR is a domain-refined, high permeability cor e steel, and represents the max tech for dry-type u nits. The Department analyzed each of the five design opt ion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, c reating 2,590 designs. 5.3.10 Design Line 13 Representative Unit Design line 13 (DL 13) represents dry-type, three-p hase, medium-voltage distribution transformers with a 

### $ 96kV BIL, ranging from 225 kVA to 2500 kVA. The re presentative unit selected for this design line is a 2000 kVA transfo rmer. The following are the technical specifications that constitute input parameters to the OPS 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 the nominal Impedance Range: 4.0–7.0 percent For DL 13, the Department selected five design opti on combinations of core steel and winding material, based on input from manufacturers and 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.5-27 Direct Labor Direct Labor Direct

Material Direct Material Overhead

Overhead Selling Selling General &

Admin. Admin. R & D

R & D Interest

Interest

Indirect Labor Full Production Cost 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 compa nies to measure cost of goods sold as the full prod uction 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 Table 5.3.14 Design Option Combinations for the Repr esentative Unit from Design Line 13 Core Material High-Voltage Conductor Low-Voltage

Conductor Core Design Type

M6 Al (wire) Al (strip) 3-Leg Mitered Cruciform M6 Cu (wire) Cu (strip) 3-Leg Mitered Cruciform M4 Cu (wire) Al (strip) 3-Leg Mitered Cruciform M3 Cu (wire) Cu (strip) 3-Leg Mitered Cruciform H-O DR* Cu (wire) Cu (strip) 3-Leg Mitered Cruciform * H-O DR is a domain-refined, high permeability co re steel, and represents the max tech for dry-type units. The Department analyzed each of the five design opt ion combinations using the matrix of A and B values described in Tables 5.3.1 and 5.3.2, c reating 2,590 designs.

5.4 MATERIAL AND LABOR INPUTS The Department uses a standard method of cost accou nting to determine the costs associated with manufacturing. This methodology is illustrate d in Figure 5.4.1, where production costs and non-production costs are combined to determine the manufacturer’s selling price of a product.

The full production cost and the non-production cos t equal the manufacturer’s selling price of the product. Full production cost is a combinat ion of direct labor, direct materials, and overhead

.5-28

The overhead contributing to full production cost i ncludes indirect labor, indirect material, maintenance, depreciation, taxes, and insurance rel ated to company assets. Non-production cost includes the cost of selling (market research, adve rtising, sales representatives, logistics), general and administrative costs, research and development (R&D), interest payments, and profit factor (not shown). Because profit factor is included in the n on-production cost, the sum of production and non-production costs is an estimate of the manufact urer’s selling price. The Department developed estimates of the costs lis ted in Figure 5.4.1 from the U.S. Industry Census Data Reports for 1992 and 1997, manufacturer interviews, and Se curities and Exchange Commission (SEC) 10-K reports for ACME Ele ctric Corporation, Powell Industries, Inc., Magnetek, Inc., and Hammond Manufacturing Company L imited. It then refined these estimates through meetings and dialogue with transformer manu facturers in early 2002. The following markups resulted: • Scrap and handling factor: 2.5 percent markup. T his markup applies to variable materials (e.g., core steel, windings, insulation). It accou nts for the handling of material (loading into assembly or winding equipment) and the scrap materi al that cannot be used in the production of a finished transformer (e.g., lengths of wire to o short to wind, trimmed core steel). • Mitered scrap factor: 4.0 percent markup. An add itional scrap markup applies to steel used in full-mitered cores. This markup represents mate rial cut from the notch in the yoke. • Factory overhead: 12.5 percent markup. Factory o verhead includes all the indirect costs associated with production, indirect materials and energy use (e.g., annealing furnace), taxes, and insurance. The Department only applied factory overhead to the direct material production costs. • Non-production: 25 percent markup. This markup r eflects costs including selling, general and administrative, R&D, interest payments, and pro fit factor. The Department applied the non-production markup to the sum of direct material , direct labor, and factory overhead. The following example shows how the Department appl ied the markups to the materials, and how it determined the manufacturer selling price. Consider a 300kVA 45kV BIL three-phase, drytype transformer designed for a $1.50 A and a $0.30 B. This design has $2,785 of materials, including M6 core steel, copper primary and secondary windings, and all the transformer hardware. There are approximately 27 hours of labor involved in manufacturing this design, resulting in a labor cost of $1,167. The factory overhead on this design is $348, as it is only applied to the material cost (i.e., 12.5 percent of $2,785). The non-production cost is $1,075, since the 25 percent is applied to the material, labor, and factory over head costs (i.e., 25 percent of $2,785 + $1,167 + $348). Thus, in total, DOE estimates this 300kVA t hree-phase transformer to have a manufacturer selling price of $5,375.

5.4.1 Material Prices The Department received considerable input from manufacturers concerning recent increases in the cost of materials, particularly core steel. The Department used prices of core steel, conducto r, mineral oil, insulation, and other materials as an input to the transformer design software used for5-29

the engineering analysis. As the price of one mate rial increases or decreases relative to the other materials, the software will modify its design and increase or decrease the amount of that material while balancing other design parameters, creating a cost-optimized transformer. Material pricing is also critical because the manufacturer’s selling pr ices calculated in the engineering analysis are based on a bill of materials that includes specific ations for pounds of steel, pounds of conductor, gallons of mineral oil, tank dimensions, and so on. Therefore, as material prices increase, so will the manufacturer’s selling price. Furthermore, as discussed in Chapter 3, energy-efficient transformers tend to incorporate more materials (e. g., pounds of core steel, pounds of conductor), making the impact of more expensive materials even more significant at higher efficiencies. The Department contracted OPS to develop material p rice estimates for the engineering analysis. OPS used data from their own records as well as data provided by transformer manufacturers and material suppliers and wholesaler s. Although not all U.S. transformer manufacturers pay the same amount per pound for ele ctrical-grade steels, due to varied contract negotiations, these prices are intended to be repre sentative of a standard quantity order for a medium- to large-scale U.S. transformer manufacture r. The Department conducted the engineering analysis using two material price scenarios: 1) a five-year average of the material prices (in constant 2004$) from 2000, 2001, 2002, 2003, and 2004, and 2 ) a more recent material price sensitivity, using material prices from the first quarter (Q1) o f 2005. OPS gathered both the five-year average and the Q1 2005 material prices in the same manner, providing consistency to the two pricing scenarios used in the engineering analysis. The co nsideration of a second set of material prices in the engineering analysis was directly in response t o comments received, during the review of the ANOPR analysis, indicating that material prices are increasing rapidly and the historical lows of recent past were unlikely to be experienced again. The results of the Q1 2005 engineering analysis are presented in Appendix 5C. The Department noted that the most critical materia l input to a distribution transformer, electrical core steel, had increased by more than 1 00 percent for some M-grades between the fiveyear average price and Q1 2005 (see Table 5.4.1). For this reason, the Department researched the grain-oriented electrical steel market to gain a be tter understanding of the main players and some of the factors influencing this significant price incr ease (see Appendix 3A). In Chapter 8 on the LCC analysis, the Department pr esents results on its sensitivity analyses conducted on various LCC inputs, which included mat erial prices. In Chapter 8, the Q1 2005 material price is referred to as the “high” price s cenario and the 2000–2004 average price scenario is called the “medium” price scenario. The Departmen t then developed a hypothetical "low" price scenario to establish a lower bound for the LCC sen sitivity analysis. It based the low price scenario on material prices in 2002 (the calender year with the lowest $/pound for M6 core steel) and reduced all the material prices in that year by 15 percent. These material prices can be found in the materia l price tables presented in this section. The result ing low-price scenario manufacturer selling prices are provided in the LCC spreadsheets.

5.4.2 Material Inputs to the Design Software—Liquid- Immersed Table 5.4.1 presents the material prices for a typi cal liquid-immersed transformer manufacturer in Q1 2005, the hypothetical low mater ial prices (for the LCC material price5-30

sensitivity, presented in Chapter 8), and the 2000– 2004 five-year average prices (all in constant 2004$). The highlighted columns are the prices tha t DOE used in the engineering analysis. Table 5.4.1 Manufacturer’s Material Prices for Liqui d-Immersed Design Lines

Material Q1 2005 $/lb. 2002 -15% 2004$/ lb. 5-yr Avg. 2004$/ lb. 2004 2004$/ lb. 2003 2004$/ lb. 2002 2004$/ lb. 2001 2004$/ lb. 2000 2004$/ lb.
M2 core steel 1.71 0.76 0.95 0.95 0.88 0.89 1.00 1.04 M3 core steel 1.63 0.65 0.80 0.80 0.78 0.76 0.82 0.86 M4 core steel 1.56 0.64 0.76 0.75 0.72 0.75 0.79 0.81 M6 core steel 1.42 0.57 0.70 0.69 0.69 0.67 0.72 0.74 ZDMH (mechanically-scribed core steel) 2.75 1.23 1.47 1 .50 1.42 1.45 1.47 1.51 SA1 (amorphous) - finished core, volume production 2.50 1.68 2.00 2.09 1.98 1.98 1.99 1.98 Copper wire, formvar, round #10-20 2.25 1.11 1.55 2.10 1 .48 1.31 1.37 1.47 Copper wire, enameled, round #7-10 flattened 2.21 1.09 1.51 2.05 1.45 1.28 1.34 1.42 Copper wire, enameled, rectangular sizes 2.65 1.18 1.7 6 2.51 2.02 1.39 1.46 1.42 Aluminum wire, formvar, round #9-17 1.56 1.15 1.43 1.53 1.41 1.35 1.43 1.45 Aluminum wire, formvar, round #7-10 1.58 1.16 1.46 1.54 1.43 1.36 1.45 1.50 Copper strip, thickness range 0.020-0.045 2.92 1.86 2. 32 2.50 2.24 2.19 2.31 2.35 Copper strip, thickness range 0.030-0.060 2.84 1.79 2. 24 2.44 2.15 2.11 2.23 2.27 Aluminum strip, thickness range 0.020- 0.045 1.66 1.30 1.54 1.60 1.58 1.53 1.47 1.53 Aluminum strip, thickness range 0.045- 0.080 1.69 1.24 1.45 1.51 1.49 1.46 1.39 1.42 Kraft insulating paper with diamond adhesive 1.56 1.32 1.59 1.56 1.54 1.55 1.62 1.66
Tank steel 0.50 0.29 0.35 0.35 0.33 0.34 0.37 0.38 Mineral oil 2.40 1.45 1.71 1.80 1.73 1.71 1.60 1.72 The Department then marked up the raw material pric es presented in Table 5.4.1 using the manufacturer’s internal markups discussed in sectio n 5.4. For example, a raw material price of $1.00/lb. would be marked up to $1.44/lb., reflecti ng the handling and scrap factor (2.5 percent), the factory overhead (12.5 percent), and the non-produc tion markup (25 percent). The Department then used the marked-up material prices as inputs to the transformer design software. During the manufacturer site visits in early 2002, the Departm ent found this approach to be consistent with that of several manufacturers who operate their own, pro prietary transformer design software. Table 5.4.2 shows the markup steps being applied to the f ive-year average material price scenario (2000–2004).
Table 5.4.2 Marked-up Material Prices for Liquid-Imm ersed Units, Five-Year Average Price

Scenario5-31

Item and Description Material Price* Scrap &

Handling Factory

Overhead NonProduction Software

Input M2 core steel $0.95 1.025 1.125 1.25 $1.37 M3 core steel $0.80 1.025 1.125 1.25 $1.17 M4 core steel $0.76 1.025 1.125 1.25 $1.10 M6 core steel $0.70 1.025 1.125 1.25 $1.01 ZDMH (mechanically-scribed core steel, finished core) $1.47 + 0.30 1.015 1.125 1.25 $2.53 SA1 (amorphous material) - finished core, volume production $2.00 1.015 1.125 1.25 $2.85 Copper wire, formvar, round #10-20 (DL 1,2,4) $1.55 1.025 1.125 1.25 $2.23 Copper wire, enameled, round #7-10 flattened (DL 3,5) $1.51 1.025 1.125 1.25 $2.18 Copper wire, enameled, rectangular sizes (DL 3) $1.76 1.025 1.125 1.25 $2.54 Aluminum wire, formvar, round #9-17 (DL 1,2,4) $1.43 1.025 1.125 1.25 $2.08 Aluminum wire, formvar, round #7-10 (DL 3,5) $1.46 1.025 1.125 1.25 $2.10 Copper strip, thickness range 0.02-0.045 (DL 1,2,4) $2.32 1.025 1.125 1.25 $3.34 Copper strip, thickness range 0.030-0.060 (DL 3,5) $2.24 1.025 1.125 1.25 $3.23 Aluminum strip, thickness range 0.02- 0.045 (DL 1,2,4) $1.54 1.025 1.125 1.25 $2.22 Aluminum strip, thickness range 0.045- 0.080 (DL 3,5) $1.45 1.025 1.125 1.25 $2.09 Kraft insulating paper with diamond adhesive $1.59 1.025 1.125 1.25 $2.29 Tank Steel $0.35 1.025 1.125 1.25 $0.50 Mineral oil (per gallon) $1.71 - 1.125 1.25 $2.40 * Five year average (2000– 2004) for materials expr essed in 2004$ per lb. ZDMH includes $0.30/lb adde r for finished
core.
Several manufacturers commented that the U.S. has a 31 percent anti-dumping import duty on core steel produced in Japan. One of the core s teels considered by the Department as a highefficiency grade steel for the liquid-immersed, wou nd-core units was ZDMH. ZDMH is a mechanically scribed, grain-oriented electrical ste el. The process for manufacturing this steel is patented, and it is only produced in Japan. For th e ANOPR analysis, the Department considered two price points for ZDMH, one reflecting what a U. S. manufacturer would pay with the import duty and the other reflecting what a manufacturer i n Mexico or Canada would pay (no duty). The duty only applies to ZDMH raw material; it does not apply to the material if ‘substantial rework’ were done prior to importation (e.g., building a tr ansformer or a core outside the U.S. and then importing it). The Department is concerned that if ZDMH offered a more cost-effective set of5-32

liquid-immersed designs for standards compliance, i t may give manufacturers outside the U.S. a competitive advantage over domestic manufacturers. For the NOPR analysis, the Department modified its use of ZDMH pricing in the engineering analysis due to input received from sev eral manufacturers. These companies indicated to the Department that, if ZDMH offered the most co st-effective liquid-immersed designs, they would out-source core fabrication to a Mexican or C anadian company and import finished cores. Finished ZDMH cores are not subject to the importat ion duty; thus, the ZDMH price did not include the 31 percent import duty, but did include an adde r for core processing. The manufacturer impact analysis (MIA, see Chapter 12) discusses the effectof this scenario on U.S. transformer manufacturer employment.
In addition to the aforementioned materials that vary during the design optimization process (e.g., core steel, windings, insulation), there are other direct materials inputs that are fixed costs and generally do not influence the design or vary with efficiency rating. These include direct materials, such as the high- and low-voltage bushings and the core clamps. The Department also prepared estimates of the tank fabrication cost, based on th e optimized transformer design (the software considers this variable) and the labor necessary to build the tank. Table 5.4.3 summarizes all the estimated fixed material costs and estimates of the tank costs for each of the five liquid-immersed design lines. For design line 1, a 50kVA single-phase pad-mounted unit, the high-voltage bushings are two universal bushing wells, 15 kV, 95 BIL, 14400V, costing $7 each. The low-voltage bushings are three threaded copper studs, 240/120V, 50 kVA, costing $20 for the set. Internal hardware costs include a core clamp, nameplate, and other miscellaneous hardware costing $25.65. The finished tank size (and associated cost) varies by design, b ut the average is approximately $130. For design line 2, a 25kVA single-phase pole-mounte d unit, the high-voltage terminal is a single, wet-process porcelain bushing assembly, 15 kV, 125 BIL, costing $6.00. The low-voltage terminals are three molded polymer bushings, 120/24 0V, 25 kVA, costing $8.00 for the set. Internal hardware costs include a core clamp, nameplate, and other miscellaneous hardware, costing $19.15. The finished tank sizes (height and diameter) vary by design, but the average is approximately $70. For design line 3, a 500kVA single-phase unit, the high-voltage connector is a single, wetprocess porcelain bushing, 25 kV, 125 BIL, costing $6.00. The low-voltage bushings are two fourhole “J” Spade 500kVA, 277V, costing $60 for the se t. The internal hardware includes a core clamp ($30), nameplate ($0.65), and miscellaneous hardwar e ($20), totaling $50.65. The design software optimized the tank cost with each design, including radiators (external cooling) for this kVA rating. The resultant finished round tank has a diameter of 33" to 52", with an average cost of approximately $500 (including radiators). For design line 4, a 150kVA three-phase, pad-mounte d unit, the high-voltage bushings are three externally clamped, universal high-voltage bu shing wells, 8.3/14.4 kV, 95 BIL, costing $7 each. The low-voltage bushings are three copper studs at $8 each. The internal hardware includes core clamps ($30), nameplate ($0.65), and miscellan eous hardware ($45), totaling $75.65 The optimized finished tank sizes measure 50 inches hig h and vary in width and depth. The finished rectangular, welded tank has an average cost of app roximately $360.5-33

For design line 5, a 1500kVA three-phase, pad-mount ed unit, the high-voltage bushings are three externally clamped, universal high-voltage bu shing wells, 15.2/26.3 kV, 125kV BIL, costing $20 each. The low-voltage bushings are four extern ally clamped bushings, each having six-hole spade, costing $160 for the set. The internal hardware includes core clamps ($60), nameplate ($0.65), and miscellaneous hardware ($45), totaling $105.65. The optimized finished tank sizes measure 70 inches high and vary in width and depth. The finished rectangular, welded tank, including radiators as specified by the design soft ware, has an average cost of approximately $800. Table 5.4.3 Summary Table of Fixed Material Costs fo r Liquid-Immersed Units

Item DL 1 DL 2 DL 3 DL 4 DL 5 High voltage bushings $14 $6 $6 $21 $60 Low voltage bushings $20 $8 $60 $24 $160 Core clamp, nameplate, and misc. hardware $25.65 $19. 15 $50.65 $75.65 $105.65 Transformer tank average cost* $130 $70 $500 $360 $800 * Transformer tank steel is used in the design opti mization software and varies with the efficiency (a nd size) of each design. DL3 and DL5 include calculated costs of ra diators, which are scaled for each design based on the required cooling surface area. 5.4.3 Material Inputs to the Design Software—Dry-typ e Table 5.4.4 presents the material prices for a typi cal dry-type transformer manufacturer in Q1 2005, the hypothetical low material prices (for the LCC material price sensitivity, presented in Chapter 8), and the 2000–2004 five-year average pri ces (all in constant 2004$). The highlighted columns are the prices used in the engineering anal ysis.5-34

Table 5.4.4 Manufacturer’s Material Prices for Dry-T ype Design Lines

Material Q1 2005 $/lb. 2002 -15% 2004$/l b. 5-yr Avg. 2004$/l b. 2004 2004$/l b. 2003 2004$/l b. 2002 2004$/l b. 2001 2004$/l b. 2000 2004$/l b. H-O DR core steel (domain-refined) 1.85 0.82 0.99 1.00 0 .92 0.97 1.01 1.04 M3 core steel 1.63 0.65 0.80 0.80 0.78 0.76 0.82 0.86 M4 core steel 1.56 0.64 0.76 0.75 0.72 0.75 0.79 0.81 M5 core steel 1.47 0.60 0.72 0.73 0.63 0.70 0.77 0.77 M6 core steel 1.42 0.57 0.70 0.69 0.69 0.67 0.72 0.74 M19 core steel (26 gauge) 0.82 0.43 0.56 0.55 0.52 0.51 0. 59 0.62 M36 core steel (29 gauge) 0.69 0.42 0.50 0.53 0.49 0.49 0. 48 0.51 M36 core steel (26 gauge) 0.65 0.36 0.45 0.51 0.44 0.42 0. 44 0.46 M43 core steel (26 gauge) 0.58 0.36 0.43 0.48 0.43 0.42 0. 41 0.43 Copper wire, rectangular 0.1 x 0.2, Nomex wrap 2.69 1.39 2.00 2.72 2.24 1.63 1.68 1.74 Aluminum wire, rectangular 0.1 x 0.2, Nomex wrap 2.05 1.71 2.06 2.04 2.01 2.01 2.10 2.13 Copper strip, thickness range 0.020- 0.045 2.92 1.86 2.32 2.50 2.24 2.19 2.31 2.35 Aluminum strip, thickness range 0.020-0.045 1.66 1.30 1.54 1.60 1.58 1.53 1.47 1.53 Nomex insulation (per pound) 18.00 15.38 18.11 18.00 17. 76 18.09 18.39 18.29 Cequin insulation (per pound) 12.00 10.54 11.99 12.00 12 .18 12.40 11.56 11.83 Impregnation (per gallon) 19.00 14.93 17.80 18.00 17.26 1 7.57 17.86 18.29 Enclosure Steel (per pound) 0.50 0.29 0.35 0.35 0.33 0.34 0.37 0.38 Winding combs (per pound) 10.00 8.79 10.24 10.00 10.15 10 .34 10.51 10.22

On the following pages, all the material prices ent ered into the design software for dry-type distribution transformers are given. As shown in t hese tables, the Department marked up the material prices before being entering them into the design software.5-35

Table 5.4.5 Marked-up Material Prices for Dry-Type U nits, Five-Year Average Price Scenario Item and Description Material Price* Scrap &

Handling Factory

Overhead NonProduction Software

Input H-O DR core steel (domain-refined) $0.99 1.025 1.125 1. 25 $1.43 M3 core steel $0.80 1.025 1.125 1.25 $1.17 M4 core steel $0.76 1.025 1.125 1.25 $1.10 M5 core steel $0.72 1.025 1.125 1.25 $1.04 M6 core steel $0.70 1.025 1.125 1.25 $1.01 M19 core steel (26 gauge) $0.56 1.025 1.125 1.25 $0.81 M36 core steel (29 gauge) $0.50 1.025 1.125 1.25 $0.72 M36 core steel (26 gauge) $0.45 1.025 1.125 1.25 $0.65 M43 core steel (26 gauge) $0.43 1.025 1.125 1.25 $0.62 Copper wire, rectangular 0.1 x 0.2, Nomex wrapped $2.00 1.025 1.125 1.25 $2.88
Aluminum wire, rectangular 0.1 x 0.2, Nomex wrapped $2.06 1.025 1.125 1.25 $2.97
Copper strip, thickness range .02- .045 $2.32 1.025 1.125 1.25 $3.34
Aluminum strip, thickness range .02- .045 $1.54 1.025 1.125 1.25 $2.22
Nomex insulation (per pound) $18.11 1.025 1.125 1.25 $26 .10 Cequin insulation (per pound) $11.99 1.025 1.125 1.25 $1 7.30 Impregnation (per gallon) $17.80 - 1.125 1.25 $25.03 Enclosure steel (per pound) $0.35 1.025 1.125 1.25 $0.50 Winding Combs (per pound) $10.24 1.025 1.125 1.25 $14.76 * Five-year average (2000–2004) for materials expre ssed in 2004$ per lb. Average compiled by Paul Goe the, Optimized Program Service, January 2005. As stated in section 5.3, the OPS software does nottake into account retooling costs associated with changing production designs. There fore, to partially capture these differential costs in the design line that had both buttlap and mitere d designs, the Department used an adder in design line 9. The adder specified an extra 10 cents per pound of core steel for full-mitered designs. More detailed costing of the retooling costs for miterin g equipment is captured in the MIA (see Chapter 12). Similar to the liquid-immersed designs, there are f ixed (and some partially variable) hardware costs associated with dry-type distributio n transformers. These are discussed individually and then summarized in Table 5.4.6. For design line 9, a 300 kVA three-phase, medium-vo ltage dry-type transformer at 45 kV BIL, the low-voltage and high-voltage terminal set costs $75. The secondary (low-voltage) bus-bar is estimated to be eight feet at $10 per foot, or $ 80. The mounting frame that attaches the core/coil assembly to the transformer enclosure costs approxi mately $36. The fiberglass dog-bone ductspacers used for this design line cost $0.42 per fo ot. The Department estimated the miscellaneous hardware costs at $25. The ventilated enclosure - a 14-gauge steel enclosure, base, and mounting5-36

feet - varies with the size of the core-coil assemb ly for the 300 kVA unit, and costs approximately $175. For design line 10, a 1500 kVA three-phase, medium- voltage dry-type transformer at 45 kV BIL, the low-voltage and high-voltage terminal set costs $120. The low-voltage bus-bar is estimated to be fourteen feet at $10 per foot, or $ 140. The mounting frame that attaches the core/coil assembly to the transformer enclosure cos ts approximately $120. The fiberglass dog-bone duct-spacers used for this design line cost $0.52 p er foot. The Department estimated the miscellaneous hardware costs at $42. The ventilate d enclosure - a 12-gauge steel enclosure, base, and mounting feet - varies with the size of the cor e-coil assembly for the 1500 kVA unit, and costs approximately $600. For design line 11, a 300 kVA three-phase, medium-v oltage dry-type at 95 kV BIL, the lowvoltage and high-voltage terminal set costs $100. The high-voltage terminal boards cost $27. The low-voltage 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 $0.42 p er foot. The Department estimated the miscellaneous hardware costs at $32. The ventilate d enclosure - a 14-gauge steel enclosure, base, and mounting feet - varies with the size of the cor e-coil assembly for the 300 kVA unit, and costs approximately $300. For design line 12, a 1500 kVA three-phase, medium- voltage dry-type at 95 kV BIL, the low-voltage and high-voltage terminal set costs $13 5. The high-voltage terminal boards cost $27. The low-voltage bus-bar is estimated to be sixteen feet at $12 per foot, or $192. The mounting frame that attaches the core/coil assembly to the t ransformer enclosure costs $125. The fiberglass dog-bone duct-spacers used for this design line cos t $0.56 per foot. The Department estimated the miscellaneous hardware costs at $54. The ventilate d enclosure - a 12-gauge steel enclosure, base, and mounting feet - varies with the size of the cor e-coil assembly for the 1500 kVA unit, and costs approximately $770. For design line 13, a 2000 kVA three-phase, medium- voltage dry-type at 125 kV BIL, the low-voltage and high-voltage terminal set costs $15 0. The high-voltage terminal boards cost $27. The low-voltage bus-bar is estimated to be eighteenfeet at $15 per foot, or $270. The mounting frame that attaches the core/coil assembly to the t ransformer enclosure costs $175. The fiberglass dog-bone duct-spacers used for this design line cos t $0.60 per foot. The Department estimated the miscellaneous hardware costs at $60. The ventilate d enclosure - a 12-gauge steel enclosure, base, and mounting feet - varies with the size of the cor e-coil assembly for the 2000 kVA unit, and costs approximately $835.5-37

Table 5.4.6 Summary Table of Fixed Material Costs fo r Dry-Type Units

Item DL 9 DL 10 DL 11 DL 12 DL 13 LV and HV terminals (set) $75 $120 $100 $135 $150 HV terminal board(s) $27 $27 $27 $27 $27 LV bus-bar $80 $140 $80 $192 $270 Core/coil mounting frame $36 $120 $42 $125 $175 Nameplate $0.65 $0.65 $0.65 $0.65 $0.65 Dog-bone duct-spacer (ft.) $0.42 $0.52 $0.42 $0.56 $0.60 Winding combs (lb.) n/a n/a $10.24 $10.24 $10.24 Misc. hardware $25 $42 $32 $54 $60 Enclosure (12, 14 gauge) ~$250 ~$600 ~$300 ~$770 ~$835 LV = low voltage HV = high voltage
5.4.4 Labor Costs Labor costs are a critical aspect of the cost of manufacturing a distribution transformer. The Department used the same hourly labor cost for both liquid and dry-type distribution transformers. It developed the hourly cost of labor using a simil ar approach to the development of the cost of materials; however, it used different markups, with the exception of the non-production markup. The Department developed the markups shown in Table 5.4.7 after reviewing publicly available information and consulting with industry experts fa miliar with transformer manufacturing in the U.S.5-38

Table 5.4.7 Labor Markups for Liquid-Immersed and Dr y-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 dis tribution transformers, except parts" Production w orkers hours and wages. ** Indirect production labor (e.g., production mana gers, quality control) as a percent of direct labor on a cost basis. Navigant Consulting, Inc. (NCI) estimate. *** Overhead includes commissions, dismissal pay, b onuses, vacation, sick leave, and social security contributions. NCI estimate. † Fringe includes pension contributions, group insur ance 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 Manu facturing," Total fringe benefits as a percent of t otal compensation for all employees (not just production workers). †† Assembly labor up-time is a factor applied to acco unt for the time that workers are not assembling pr oduct and/or reworking unsatisfactory units. The markup of 42 p ercent represents a 70 percent utilization (multipl ying by 100/70). NCI estimate. ††† Non-production markup reflects non-production cost s, including selling, general, and administrative, R&D, interest payments, and profit factor markups. Source: US Ind ustry Census Data for 1992 and 1997; SEC 10-K repor ts for Acme, Powell, Magnetek and Hammond; Manufacturer intervie ws, 2002. There are several labor steps involved in manufactu ring a liquid-immersed transformer. The Department prepared estimates of the amount of labo r involved, some varying with the transformer design and others fixed on a per-unit basis. These steps are described below, and the amount of time dedicated to each is given in Table 5.4.8. • Cutting, Forming, and Annealing - This task involv es cutting the core steel to lengths on a distributed-gap core cutting machine, forming the r esulting “donut” of core steel into a rectangular shape in a hydraulic press, and then an nealing the core in a high temperature annealing furnace. The labor involved in these act ivities is calculated based on the weight of core (pounds) multiplied by a constant, which varie s with the lamination thickness of the core steel. For DL1, DL2, and DL4, on M6 designs t he constant is 0.08, M4 is 0.10, M3 is 0.125, and M2 is 0.16. For DL3 and DL5, on M6 desi gns the constant is 0.05, M4 is 0.07, M3 is 0.09, and M2 is 0.11. For the prefabricated c ores—ZDMH and SA1 (Amorphous material)—the labor for cutting, forming, and annea ling is set to zero. • Primary Winding - This task entails winding the pr imary conductor of the transformer. It includes set-up time as well as winding time. The labor hours vary with the number of turns (per phase) for the primary winding. For DL1, DL2, and DL4 the winding time is 0.0001 hours per turn. For these smaller kVA ratings (and smaller cores), this rate is very low5-39

because some of the larger, liquid-immersed manufac turers wind multiple coils simultaneously on the same winding machine. This m anufacturing approach improves throughput and productivity at the facility. The r ate of 0.0001 hours per turn equates to approximately one-third of a second per turn. On D L3 and DL5, due to the larger coil size associated with these units, the winding time is 0. 002 hours per turn (approximately 7.2 seconds per turn). • Secondary Winding - This task involves winding the secondary conductor of the transformer. It includes set-up time as well as wi nding time. On a distribution (step-down) transformer, the number of secondary turns is alway s less than the primary. For the liquidimmersed units, which are taking a relatively high primary voltage and dropping to below 600V, the turns ratio can be as large as 100:1. Fo r this reason, the hours per turn of the secondary are considerably higher than the primary, because there are fewer turns over which to amortize the set-up time as well as a slow er winding rate for the secondary, which has larger cross-sectional area than the primary. For DL1, DL2, and DL4, the hours per turn of the secondary are 0.015 (54 seconds per turn); f or DL3 and DL5, the hours per turn are 0.02 (72 seconds per turn). • Lead Dressing - Once a wound coil is taken off the winding machine, work must be performed on the leads to prepare them for the next manufacturing step. Enamel is removed to enable good electrical connection and an insulat ing tubing is slipped over the cable. This is a fixed amount of labor, and does not vary with efficiency or design. The estimated times are 0.5 hours for DL1 and DL4, 0.07 hours for DL2, 0.35 hours for DL3, and 1.0 hour for DL5. • Coil Varnishing and Baking - Once they are complet e, the coils are vacuum-dipped in varnish and baked in an oven to cure the varnish an d enhance the integrity of the coil. This task varies slightly with kVA rating, but does not vary with efficiency. The estimated times are 0.10 hours for DL1, 0.07 hours for DL2, 0.15 ho urs for DL3, 0.17 hours for DL4, and 0.25 hours for DL5. • Core Assembly (“Lacing”) - This task involves asse mbling and banding the annealed wound core laminations around varnished windings. The an nealed bundle of core steel is disassembled from the inside out by grabbing approx imately 1/4 inch bundles, then reassembling the core steel around the coils. Once all the laminations are reassembled, the core material is clamped to maintain the structure. The activity involves feeding a banding strip around the core material and using a locking clamp to compress and contain the core material. The labor rate varies with stack height and lamination thickness for each design. The time for core assembly is approximately 0.5 hou rs for DL1, 0.3 hours for DL2, 1.5 hours for DL3, 1 hour for DL4, and 3.5 hours for DL5. • Tanking and Impregnating - This task involves inse rting and fastening the core/coil assembly into the tank. Then, a vacuum is pulled and oil is introduced to the tank. On round tanks, the vacuum and oil step is done through a lid attac hed to the top of the unit. On the rectangular and pad-mounted tanks, the vacuum is pu lled in a chamber, which takes a little longer per unit. Finally, tap changers and bushing s are mounted, and bolted connections made. The time for this activity does not vary wit h design or efficiency, but it does vary by kVA rating and tank shape. The estimates of labor time for the five liquid-immersed design5-40

lines are: 0.5 hours for DL1, 0.11 hours for DL2, 0.3 hours for DL3, 0.62 hours for DL4, and 1.4 hours for DL5. • Inspection - This activity involves verifying that the transformer is assembled properly and is up to a manufacturer's quality specification. This task includes inspecting the lead dressing, lead tie-up, and other quality certification specif ications. The time for this activity does not vary with design or efficiency, but it does vary by kVA rating. The estimates of labor time are 0.10 hours for DL1 and DL3, 0.05 hours for DL2, 0.15 hours for DL4, and 0.20 hours for DL5. • Preliminary Test - This step involves conducting a test to ensure that the core/coil meets the specified turns ratio, polarity, core loss, etc. The time for this activity does not vary with design or efficiency, but it does vary by kVA ratin g. The estimates of labor time are 0.10 hours for DL1, DL3, and DL4; 0.03 hours for DL2; an d 0.15 hours for DL5. • Final Test - This activity involves testing of the final, assembled unit, with the core/coil assembly immersed in oil. This test verifies that the unit meets the guaranteed values, including core and coil losses, impedance, and diel ectric tests. The time for this activity does not vary with design or efficiency, but it doe s vary by kVA rating. The estimates of labor time are 0.15 hours for DL1 and DL3, 0.07 hou rs for DL2, 0.20 hours for DL4, and 0.25 hours for DL5. • Marking and Miscellaneous - This task involves pre paring any extra markings around the bushings or on the surface of the transformer and o ther miscellaneous labor associated with preparing the finished transformer for the customer . The time for this activity does not vary with design or efficiency, but it does vary by kVA rating. The estimates of labor time are 0.28 hours for DL1, 0.07 hours for DL2, 0.35 hours for DL3, 0.31 hours for DL4, and 0.75 hours for DL5. • Pallet Loading - This activity involves preparing the transformer for shipping to the customer. This includes loading the finished trans former onto a pallet, banding the transformer to the pallet, wrapping, and all other necessary steps for shipping. The time for this activity does not vary with design or efficien cy, but it does vary by kVA rating. The estimates of labor time are 0.27 hours for DL1, 0.0 6 hours for DL2, 0.5 hours for DL3 and DL4, and 3 hours for DL5.
Table 5.4.8 summarizes the estimates of labor time that DOE used for the five liquidimmersed units.5-41

Table 5.4.8 Summary of Labor Times for Liquid-Immers ed Units Labor Activity DL 1 hrs. DL 2

hrs. DL 3

hrs. DL 4

hrs. DL 5

hrs. Cutting, Forming, & Annealing ~1.00 ~0.75 ~4.00 ~3.00 ~8 .50 Primary Winding (hrs/turn) 0.0001 0.0001 0.002 0.0001 0. 002 Secondary Winding (hrs/turn) 0.015 0.015 0.020 0.015 0.0 20 Lead Dressing 0.50 0.07 0.35 0.50 1.00 Baking Coils 0.10 0.07 0.15 0.17 0.25 Core Assembly ~0.50 ~0.30 ~1.50 ~1.00 ~3.50 Tanking and Impregnating 0.50 0.11 0.30 0.62 1.40 Inspection 0.10 0.05 0.10 0.15 0.20 Preliminary Test 0.10 0.03 0.10 0.10 0.15
Final Test 0.15 0.07 0.15 0.20 0.25 Pallet Loading 0.27 0.06 0.50 0.50 3.00 Marking and Misc. 0.28 0.07 0.35 0.31 0.75
Likewise, there are several labor steps involved inmanufacturing a dry-type transformer. The Department prepared estimates of the amount of labor involved, some varying with the transformer design and others fixed on a per-unit b asis. These steps are described below, and the amounts of time dedicated to each are summarized inTable 5.4.9. • Core Stacking - This task involves stacking (assem bling) the cut steel laminations into a distribution transformer core. The amount of labor for this task varies by kVA rating, stack height, and whether the core is grain-oriented or n on-oriented. Thus, the labor for core stacking varies with the efficiency of the transfor mer. Approximate labor hours for core stacking vary from as short as 0.45 hours/inch for a 300 kVA, 45kV BIL three-phase, medium-voltage unit to 0.9 hours/ inch for a 2000 kVA, 125kV BIL three-phase, mediumvoltage unit. • Primary Winding - This task encompasses winding th e primary conductor of the transformer. It includes set-up time as well as winding time. T he labor hours vary with the number of turns (per phase) for the primary winding. The 300 kVA units, DL9 and DL11, both have 0.01 hours/turn. The 1500kVA units, DL10, DL12, an d the 2000kVA DL13 all have the same winding time—0.0125 hours/turn. • Secondary Winding - This task involves winding the secondary conductor of the transformer. It includes set-up time as well as wi nding time. The hours per turn of the secondary are considerably higher than the primary, because there are fewer turns over which to amortize the set-up time as well as a slow er winding rate for the secondary, which has larger cross-sectional area. The hours per tur n vary from 0.035 to 0.125, depending on the kVA rating (design line).5-42

• Lead Dressing - Once a wound coil is taken off the winding machine, work must be performed on the leads to prepare them for the next manufacturing step. Enamel is removed to enable good electrical connection and an insulat ing tubing is slipped over the cable. For a given kVA rating, this is a fixed amount of labor, and does not vary with efficiency or design. The range is from 0.60 to 1.0 hours per un it. • Assembly - This task involves installing the wound cores onto the partially assembled core, and then lacing the top (yoke) laminations to compl ete the core. It also includes setting all the core clamps and completing the core/coil assemb ly. The Department assumed the assembly time varies by kVA rating, but does not vary by design within a kVA rating. For example, the assembly time for a 1500kVA three-phas e unit is estimated at six hours, while the assembly time for a 300kVA three-phase unit is estimated at three hours. • Inspection - This activity involves verifying that the transformer is assembled properly and is up to a manufacturer's quality specification. It i ncludes inspecting the lead dressing, lead tie-up, and other quality certification specificati ons. The time for this activity does not vary with design or efficiency, but it does vary by kVA rating. The time estimates vary from 0.10 hours (6 minutes) for the smaller kVA ratings to 0. 25 hours (15 minutes) for the larger units. • Preliminary Test - This step involves conducting a test to ensure that the core/coil meets the specified turns ratio, polarity, core loss, etc. The time for this activity does not vary with design or efficiency, but it does vary by kVA ratin g. The estimates of labor time range from 0.10 hours (6 minutes) for the smaller kVA ratings to 0.5 hours (30 minutes) for the larger units. • Final Test - This activity involves testing the fi nal, assembled unit, with the core/coil assembly immersed in oil. This test verifies that the unit meets the guaranteed values, including core and coil losses, impedance, and diel ectric tests. The time for this activity does not vary with design or efficiency, but it doe s vary by kVA rating. Similar to the preliminary test, the labor time estimates range fr om 0.15 hours (9 minutes) for the smaller kVA ratings 0.75 hours (45 minutes) for the larger units. • Marking and Miscellaneous - This task involves pre paring any extra markings on the terminal board or on the surface of the transformer , and other miscellaneous labor associated with preparing the finished transformer for the cus tomer. The time for this activity does not vary with design or efficiency, but it does vary by kVA rating. The labor estimate ranges from 0.70 hours at the low end to 2.2 hours at the higher kVA ratings. • Packing - This activity involves preparing the transformer for shipping to the customer. This includes loading the finished transformer onto a pa llet, banding the transformer to the pallet, wrapping, and all other necessary steps for shippin g. The time for this activity does not vary with design or efficiency, but it does vary by kVA rating. The time estimate ranges from 1.0 hours at the low end to 2.0 hours at the higher kVA ratings. • Enclosure Manufacturing - The labor estimate for t his task encompasses all activity associated with the cutting, forming, assembly, pri ming, painting, and preparation of the enclosure. This labor estimate varies with the kVA rating, spanning from five hours for the 300kVA up to eight hours for the 1500 and 2000kVA c abinets.5-43

Table 5.4.9 presents the hours of labor needed to c omplete each step in the manufacturing process for all design lines containing dry-type tr ansformers. Table 5.4.9 Summary of Labor Times for Dry-Type Unit s

Labor Activity DL 9 hrs. DL 10

hrs. DL 11

hrs. DL 12

hrs. DL 13

hrs. Core Stacking (hrs/inch) 0.45-0.55 0.70 0.70 0.80 0.90 Primary Winding (hrs/turn) 0.01 0.0125 0.01 0.0125 0.012 5 Secondary Winding (hrs/turn) 0.035 0.125 0.035 0.125 0.1 25 Lead Dressing 0.60 1.00 0.60 1.00 1.00 Assembly 3.00 6.00 4.00 6.00 6.00 Inspection 0.10 0.25 0.10 0.25 0.25 Preliminary Test 0.10 0.50 0.15 0.50 0.50
Final Test 0.15 0.75 0.25 0.75 0.75 Enclosure Manufacturing 5.00 8.00 5.00 8.00 8.00 Packing 1.00 2.00 1.00 2.00 2.00 Marking and Miscellaneous 0.70 2.20 0.80 2.20 2.205-44

5.5 RESULTS OF THE ANALYSIS ON EACH DESIGN LINE This section provides a visual representation of th e results of the engineering analysis. The scatter plots in this section show the relationship between the manufacturer’s selling price and efficiency for each of the 10 design lines. Each d ot on the plots represents one unique design created by the software at a given manufacturer’s s elling 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, A/B combination, and the variable design parameters generated by the design software. In addition to the results pr ovided in this section, the Department prepared scatter plots depicting the engineering analysis re sults for the 10 representative units, including watts of core and coil loss and the weight by effic iency (see Appendix 5A). As discussed earlier in this chapter, the Departmen t received several comments on the ANOPR analysis that material prices, and particular ly core steel, were experiencing a rapid increase. Therefore, in addition to its analysis on a five-ye ar average material price (2000–2004) presented here, the Department also conducted a current price scenario of Q1 2005. The engineering analysis results of the Q1 2005 material price scenario are presented in Appendix 5C, along with a comparison between these material prices and the fi ve-year average. The Department also calculated a hypothetical low-materials-price scenario, which represents a 15 percent reduction over the materials prices in 2002 (the year in which M6 had the lowest $/pound between 2000 and 2004). The results of the low-price scenario are included in the LCC spreadsheets, where they were used for an LCC sensitivity analysis.5-45

Figure 5.5.1 presents a plot of the manufacturer se lling prices and efficiency levels for the full database of designs for the representative uni t from design line 1, a 50kVA single-phase, liquidimmersed, pad-mounted distribution transformer. Th e efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and ar e corrected for temperature. The following observations can be made about this scatter plot: • NEMA’s TP 1-2002 efficiency level of 98.9 percent is met by most M3 and M2 core designs. However, many of the M6 core designs exhi bit efficiencies below this level. • The amorphous metal (SA1) core extends the availab le efficiency for the transformers beyond 99.6 percent, but at a significant cost.

500 1,000 1,500 2,000 2,500 3,000

98.40% 98.60% 98.80% 99.00% 99.20% 99.40% 99.60% 99.80% Efficiency at 50% load, Temperature CorrectedManufacturer Selling Price ($) M6AlAl_sh M6CuAl_sh M3AlAl_sh M3CuAl_sh M2CuAl_sh M2CuCu_sh ZDMHCuCu_sh SA1CuCu_sh

Figure 5.5.1 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 15-46

Figure 5.5.2 presents a plot of the manufacturer sa les prices and efficiency levels for the full database of designs for the representative unit fro m design line 2, a 25kVA single-phase, liquidimmersed, pole-mounted distribution transformer. T he efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and ar e corrected for temperature. The following observations can be made about this scatter plot: • The NEMA TP 1-2002 standard of 98.7 percent can be achieved with several design option combinations, including M3CuAl and M3CuCu. • In most cases, the maximum efficiency available wi th conventional silicon core steels is approximately 99.2 percent. However, the amorphous metal (SA1) provides efficiencies up to about 99.5 percent.

400 600 800 1,000 1,200 1,400 1,600 1,800

98.00% 98.20% 98.40% 98.60% 98.80% 99.00% 99.20% 99.40% 99. 60% 99.80% Efficiency at 50% load, Temperature CorrectedManufacturer Selling Price ($) M6AlAl_sh M6CuAl_sh M4AlAl_sh M4CuAl_sh M3CuAl_sh M3CuCu_sh M2CuAl_sh M2CuCu_sh ZDMHCuCu_sh SA1CuCu_co

Figure 5.5.2 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 25-47

Figure 5.5.3 presents a plot of the manufacturer sa les prices and efficiency levels for the full database of designs for the representative unit fro m design line 3, a 500kVA single-phase, liquidimmersed distribution transformer with radiators. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and ar e corrected for temperature. The following observations can be made about this scatter plot: • All design option combinations have designs that m eet or exceed the NEMA TP 1-2002 efficiency of 99.3 percent. • In most cases, the maximum efficiency available is limited to approximately 99.6 percent. However, the amorphous metal design option combinat ion provides efficiencies up to about 99.75 percent, with an available range from about 9 9.35 percent to nearly 99.75 percent.

1,000 3,000 5,000 7,000 9,000 11,000 13,000 15,000

98.90% 99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% 99. 70% 99.80% Efficiency at 50% load, Temperature CorrectedManufacturer Selling Price ($) M6AlAl_sh M4CuAl_sh M3CuAl_sh M2CuAl_sh M2CuCu_sh ZDMHCuCu_sh SA1CuCu_co

Figure 5.5.3 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 35-48

Figure 5.5.4 presents a plot of the manufacturer sa les prices and efficiency levels for the full database of designs for the representative unit fro m design line 4, a 150kVA three-phase, liquidimmersed distribution transformer. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected f or temperature. The following observations can be made about this scatter plot: • At the lower efficiencies, the M6 and M4 steel cor es offer a low-cost option for increasing efficiency, but do not meet the NEMA TP 1-2002 effi ciency standard of 98.9 percent. • The amorphous metal design option combination exte nds the available efficiency for the transformers up to 99.6 percent, but at a significant cost.

1,500 2,500 3,500 4,500 5,500 6,500 7,500

98.20% 98.40% 98.60% 98.80% 99.00% 99.20% 99.40% 99.60% 99. 80% Efficiency at 50% load, Temperature CorrectedManufacturer Selling Price ($) M6AlAl_co M4AlAl_co M3CuAl_co M2CuAl_co M2CuCu_co ZDMHCuCu_co SA1CuCu_co

Figure 5.5.4 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 45-49

Figure 5.5.5 presents a plot of the manufacturer sa les prices and efficiency levels for the full database of designs for the representative unit fro m design line 5, a 1500kVA three-phase, liquidimmersed distribution transformer. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and are corrected f or temperature. The following observations can be made about this scatter plot: • Every design option combination has designs that m eet the NEMA TP 1-2002 efficiency of 99.3 percent; however, many of the M6 and M4 core d esigns exhibit efficiencies lower than 99.3 percent. • Beyond 99.5 percent, the SA1 core provides additio nal efficiency with increased cost.

0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000

98.90% 99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% 99. 70% 99.80% Efficiency at 50% load, Temperature CorrectedManufacturer Selling Price ($) M4AlAl_co M4CuAl_co M3CuAl_co M2CuAl_co M2CuCu_co ZDMHCuCu_co SA1CuCu_co

Figure 5.5.5 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 55-50

Figure 5.5.6 presents a plot of the manufacturer sa les prices and efficiency levels for the full database of designs for the representative unit fro m design line 9, a 300kVA three-phase, mediumvoltage, dry-type transformer with a 45kV BIL. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load and ar e corrected for temperature. The following observations can be made about this scatter plot: • NEMA’s TP 1-2002 efficiency level for this unit is 98.6 percent efficient. 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 fraction of an ef ficiency level (e.g., from 99.0 percent to 99.5 percent) can almost double the price.

4,000 5,000 6,000 7,000 8,000 9,000 10,000 11,000 12,000

98.20% 98.40% 98.60% 98.80% 99.00% 99.20% 99.40% 99.60% Efficiency at 50% load, Temperature CorrectedManufacturer Selling Price ($) M6AlAl_bl M6CuCu_mt M5AlAl_mt M3CuAl_mt HOCuCu_mt

Figure 5.5.6 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 95-51

Figure 5.5.7 presents a plot of the manufacturer sa les prices and efficiency levels for the full database of designs for the representative unit fro m design line 10, a 1500kVA three-phase, medium-voltage, dry-type transformer with a 45kV BI L. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate l oad and are corrected for temperature. The following observations can be made about this scatt er plot: • NEMA’s TP 1-2002 efficiency level of 99.1 percent is met by M4, M3, and HO core steel designs. • As the efficiency increases, the laser-scribed (H- O DR) and M3 steel cores have similar costs.

7,000 12,000 17,000 22,000 27,000 32,000 37,000 42,000

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 CorrectedManufacture Selling Price ($) M6AlAl_cf M6CuCu_cf M4CuAl_cf M3CuCu_cf HOCuCu_cf

Figure 5.5.7 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 105-52

Figure 5.5.8 presents a plot of the manufacturer sa les prices and efficiency levels for the full database of designs for the representative unit fro m design line 11, a 300kVA three-phase, mediumvoltage, dry-type transformer with a 95kV BIL. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate load. The following observations can be made about this scatter plot: • The least-cost high-efficiency design path at 50 p ercent load varies between the M3, M4, and H-O DR core 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, and many of the M6 designs do not meet the NEMA TP 1-20 02 efficiency level of 98.5 percent.

4,000 6,000 8,000 10,000 12,000 14,000 16,000

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 CorrectedManufacturer Selling Price ($) M6CuCu_mt M4CuAl_mt M3CuCu_mt HOCuCu_mt M6AlAl_mt

Figure 5.5.8 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 115-53

Figure 5.5.9 presents a plot of the manufacturer sa les prices and efficiency levels for the full database of designs for the representative unit fro m design line 12, a 1500kVA three-phase, medium-voltage, dry-type transformer with a 95kV BI L. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate l oad. The following observations can be made about this scatter plot: • NEMA’s TP 1-2002 efficiency level of 99.0 percent is met by M4, M3, and HO core steel designs. • Above 99.3 percent efficiency, the H-O DR steel de sign option combination has a slight cost advantage over the M3 core.

15,000 20,000 25,000 30,000 35,000 40,000 45,000

98.60% 98.80% 99.00% 99.20% 99.40% 99.60% Efficiency at 50% load, Temperature CorrectedManufacturer Selling Price ($) M6AlAl_cf M6CuCu_cf M4CuAl_cf M3CuCu_cf HOCuCu_cf

Figure 5.5.9 Scatter Plot of Manufacturer Selling Pr ice and Efficiency for Design Line 125-54 12,000 22,000 32,000 42,000 52,000 62,000

98.90% 99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% 99. 70% Efficiency at 50% load, Temperature CorrectedManfuacturerSelling Price ($) M6AlAl_cf M6CuCu_cf M4CuAl_cf M3CuCu_cf HOCuCu_cf

Figure 5.5.10 Scatter Plot of Manufacturer Selling P rice and Efficiency for Design Line 13 Figure 5.5.10 presents a plot of the manufacturer s ales prices and efficiency levels for the full database of designs for the representative uni t from design line 13, a 2000kVA three-phase, medium-voltage, dry-type transformer with a 125kV B IL. The efficiency levels shown in this plot represent transformers at 50 percent of nameplate l oad and are corrected for temperature. The following observations can be made about this scatt er plot: • NEMA’s TP 1-2002 efficiency level of 99.0 percent is met by all core steel design option considerations considered by the Department. • At efficiency levels of 99.3 percent and above, th e M3 steel core and H-O DR steel cores have similar costs and efficiency gains.5-55

5.6 FOUR EXAMPLE TRANSFORMER DESIGNS AND COST BREAKD OWNS This section presents some of the OPS transformer d esigns from the Department’s engineering analysis database. As discussed earlie r, to prepare a cost-efficiency relationship on selected representative units, the Department contr acted OPS, a software company specializing in transformer design since 1969. Using a range of input parameters and material prices, OPS created more than 33,000 transformer designs for the Depart ment’s analysis. For each design, the software generated specific information about the core and c oil, including physical characteristics, dimensions, material requirements, and mechanical c learances, as well as a complete electrical analysis of the final design. For information on O PS and their software, visit their website: http://www.opsprograms.com/home.html. To illustrate the typical output from the OPS softw are, two designs from each of the two superclasses (i.e., liquid-immersed and medium-volt age, dry-type) are presented in this section. As these practical designs illustrate, the software ou tput was used to create a bill of materials, which DOE marked up to arrive at the manufacturer’s selli ng price. The OPS software provides an electrical analysis including efficiency, which, wh en plotted with the manufacturer’s selling price, constitutes the primary output of the engineering analysis. The four distribution transformers presented are tw o each from two design lines—1 and 12. Across all the design lines, the complete database of designs contains 33,152 distribution transformer specification and winding sheets, bills of materials, and performance reports. This design database was used by the LCC analysis (see C hapter 8) as it simulated purchases of distribution transformers in the marketplace. Design Line 1: 50 kVA single-phase, liquid-immersed • M6 core steel with an aluminum primary and secondary windings (M6AlAl) at a $0.00 A and a $0.00 B evaluation formula. • M3 core steel with a copper primary winding and analuminum secondary winding (M3CuAl) at a $1.50 A and a $0.38 B evaluation form ula. Design Line 12: 1500 kVA three-phase, medium-voltage, dry-type • M6 core steel with aluminum primary and secondary windings (M6AlAl) at a $0.00 A and a $0.00 B evaluation formula. • M3 core steel with copper primary and secondary wi ndings (M3CuCu) at a $0.50 A and a $0.08 B evaluation formula. For each of the four designs presented, the design detail report is followed by a bill of materials showing the cost calculation, and a pie c hart providing a breakdown of the final selling price.

5.6.1 Design Details Report for Non-Evaluated Transf ormer from Design Line 1 A design specification report for a 50kVA single-ph ase, liquid-immersed transformer appears below. This design incorporates M6 core st eel, with an aluminum primary and an aluminum secondary conductor. The evaluation facto rs for this design are $0.00 A and $0.00 B.5-56

The bill of materials and associated breakdown of c osts for this design are also reported, after the design and electrical analysis reports.

OPTIMIZED PROGRAM SERVICE

CLEVELAND OHIO 101800 2005- 3- 1 5:40: 6 DG-CORE SHELL TYPE TRANSFORMER NL1PM6ALAL
FREQUENCY 60.0 KVA RATING 50.00 @ 100.00% DUTY CYCLE
CORE DG-M6 M 6 THICKNESS .0140
D: 6.738 E: 2.073 F: 3.104 G: 7.476 EFF. AREA 2 6.952 WEIGHT 203.850
WINDING FORM: INS. DIM. 6.988 X 4.331 THICKNESS .072 LENGTH 6.976

COIL SPECIFICATIONS

-------------------
WNDG WIRE LENGTH MEAN TURN S MARGIN WT

--------------------------------------------------- ------------------- S1 .0267X 6.2262 AL 31.83 25.47 .375 6.204 P1 1 #14.5 ROUND AL 5643.34 35.83 .375 18.182 S2 .0267X 6.2262 AL 57.67 46.13 .375 11.238
NUMBER OF COILS 1 TOTAL BARE CONDUC TOR WEIGHT 35.558 WNDG TURNS LO TAP HI TAP LAYRS T/L LAYR INS SEC. INS BUILD

--------------------------------------------------- ------------------- S1 15.0 15 1.0 1(.00500) 1(.03000) .471 P1 1800.0 1710.0 1890.0 21 92.0 3(.00500) 1(.10000) 1.677 S2 15.0 15 1.0 1(.00500) 1(.05000) .471

TOT AL BUILD(%) 92.51
WNDG TAPS: TURNS( VOLTS)

--------------------------------------------------- ------- P1 1755.0( 14040.00) 1845.0( 14760.00) 1890.0( 15120.00)

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

--------------------------------------------------- ------------- S1 3 .125 X .125 IN. END P1 6 .125 X .125 IN. END .125 X .1 25 IN. END S2 1 .125 X .125 IN. END .125 X .1 25 IN. END

ELECTRICAL ANALYSIS

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

--------------------------------------------------- ------------------- P1 14400.00 13680.00 15120.00 34.5 3.541 27.52329 1293. S1 118.32 10.0 208.330 .00256 1253. 1.4 S2 117.77 10.0 208.330 .00463 1253. 1.95-57

F.L. N.L. FLUX DENS. 17.120 17.262 LEAKAGE INDUCTAN CE MHYS 217.723 CORE LOSS 174.699 179.762 POWER FACTOR 1.0000 COIL LOSS 828.787 .028 IMPEDANCE % 2.54 EXCIT. VA 367.167 417.373 EFFICIENCY % 98.03 EXCIT. CURR. .025 .029 TANK OIL GAL 41.86
AMBIENT TEMP. 20.00 NOMINAL LENGT H 14.50 TEMP.RISE 65.00 NOMINAL DEPT H 16.20 OPERATING TEMP. 85.00 NOMINAL HEIGH T 11.62

2 COND. I R LOSS = 806.3795 COND. EDDY CURRENT LOSS = 2.2476 OTHER STRAY LOSS = 20.1595 K VALUE = 1.0000

%LOAD %REG %EFF %IR %IX %IZ CO IL LOSS TEMP. RISE

--------------------------------------------------- --------------------- 25 .35 98.24 .341 .504 .608 45.690 28.6 35 .50 98.49 .484 .703 .854 90.911 33.6 50 .75 98.54 .717 1.004 1.234 192.395 44.2 65 1.03 98.43 .980 1.307 1.633 341.577 58.6 75 1.22 98.32 1.156 1.509 1.901 464.858 65.0 100 1.64 98.03 1.545 2.018 2.542 828.772 65.0 125 2.07 97.70 1.938 2.531 3.188 1299.377 65.0

Table 5.6.1 provides the bill of materials which wa s calculated from the OPS design details report. This bill of materials uses the raw materi al prices given in this Chapter for fixed and variable materials used in building the transformer . These materials are then marked up at the bottom of the table to arrive at the manufacturer’s selling price. This table provides the bill of materials for a non-evaluated transformer from desi gn line 1, a 50kVA single-phase, liquidimmersed, pad-mount M6 design, with an aluminum pri mary and an aluminum secondary. The Department generated this design using a $0.00 A an d a $0.00 B.5-58

Bill of Materials and Labor for liquid-immersed, si ngle-phase, pad-mount, 50kVA A$ Input $0.00 B$ Input $0.00 Efficiency at 50% load 98.56%

Material item Type quantity $ each $ total Core steel* (lb) M6-.014 204 0.70 $ 143.49

$ Primary winding* (lb) Aluminum wire, formvar, round #9-17 18 1.43 $ 26.00

$ Secondary windings* (lb) Aluminum strip, thickness r ange 0.02-0.045 17 1.54 $ 26.90

$ Winding form & insulation* (lb) Kraft insulating pap er with diamond adhesive 4 1.59 $ 5.59

$ Oil (gal) - 42 1.71 $ 71.57

$ Tank

- 1 132.95 $ 132.95

$ Core clamp - 1 15.00 $ 15.00

$ Nameplate - 1 0.65 $ 0.65

$ Bushings HV & LV 1 34.00 $ 34.00

$ Misc. hardware - 1 10.00 $ 10.00

$ Scrap factor 1.0% 2.02 $ Total Material Cost 468.17 $

Labor item hours rate $ total Lead dressing 0.50 42.77 21.39 $ Inspection 0.10 42.77 4.28 $ Baking coils 0.10 42.77 4.28 $ Tanking and impregnating 0.50 42.77 21.39 $ Preliminary test 0.10 42.77 4.28 $ Final test 0.15 42.77 6.42 $ Pallet loading 0.27 42.77 11.55 $ Marking and miscellaneous 0.28 42.77 11.98 $ Winding the primary 0.19 42.77 8.08 $ Winding the secondary 0.45 42.77 19.25 $ Cutting, forming, and annealing 0.38 42.77 16.31 $ Core assembly 0.29 42.77 12.23 $ Handling and slitting factor (on material) 1.50% 3.03 $ Total Labor 3.306 42.77 144.44 $ Manufacturing Cost (Material + Labor) 612.61 $ Factory Overhead (Materials only) 12.5% 58.52 $ Non-production Cost Markup 25.0% 167.78 $ Manufacturer Selling Price 838.91 $ * indicates those items to which the scrap factor ( 1.0%) and the handling and slitting factor (1.5%) a re applied.
This bill of materials is based on non-rounded core dimensions. Table 5.6.1 Bill of Materials for Non-Evaluated Tran sformer from Design Line 15-59

Figure 5.6.1 provides a summary of the costs contri buting to the total selling price of the non-evaluated transformer from design line 1. For this design, approximately 56 percent of the final manufacturer selling price is direct material and s crap. Labor accounts for 17 percent of the price and, together, the factory overhead and selling pri ce account for 27 percent.

5.6.2 Design Details Report for Evaluated Transforme r from Design Line 1 A design specification report for a 50kVA single-ph ase, liquid-immersed transformer appears below. This design incorporates M3 core st eel, with a copper primary and an aluminum secondary. The evaluation factors for this design are $1.50 A and $0.38 B. The bill of materials and associated breakdown of costs for this design a re also reported, after the design and electrical analysis reports.

OPTIMIZED PROGRAM SERVICE
CLEVELAND OHIO 101800 2005- 3- 1 8:52:41 DG-CORE SHELL TYPE TRANSFORMER NL1PM3CUAL
FREQUENCY 60.0 KVA RATING 50.00 @ 100.00% DUTY CYCLE
CORE DG-M3 M 3 THICKNESS .0090
D: 7.635 E: 1.786 F: 3.048 G: 7.372 EFF. AREA 2 5.909 WEIGHT 188.488
WINDING FORM: INS. DIM. 7.885 X 3.758 THICKNESS .072 LENGTH 6.872 Core/Coils 23%

Other Material 33% Labor 17% Factory Overhead 7% Selling Factor

20%

Figure 5.6.1 Manufacturer Selling Price Breakdown, N on-Evaluated

Transformer from Design Line 15-60

COIL SPECIFICATIONS

-------------------
WNDG WIRE LENGTH MEAN TURN S MARGIN WT

--------------------------------------------------- ------------------- S1 .0305X 6.1220 AL 35.24 26.43 .375 7.697 P1 1X 1 #16 ROUND H CU 6087.06 36.23 .375 45.437 S2 .0305X 6.1220 AL 61.30 45.97 .375 13.387
NUMBER OF COILS 1 TOTAL BARE CONDUC TOR WEIGHT 66.520 WNDG TURNS LO TAP HI TAP LAYRS T/L LAYR INS SEC. INS BUILD

--------------------------------------------------- ------------------- S1 16.0 16 1.0 1(.00500) 1(.03000) .563 P1 1920.0 1824.0 2016.0 19 107.0 4(.00500) 1(.10000) 1.423 S2 16.0 16 1.0 1(.00500) 1(.05000) .563

TOT AL BUILD(%) 91.85
WNDG TAPS: TURNS( VOLTS)

--------------------------------------------------- ------- P1 1872.0( 14040.00) 1968.0( 14760.00) 2016.0( 15120.00)

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

--------------------------------------------------- ------------- S1 3 .125 X .125 IN. END P1 6 .125 X .125 IN. END .125 X .1 25 IN. END S2 1 .125 X .125 IN. END .125 X .1 25 IN. END

ELECTRICAL ANALYSIS

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

--------------------------------------------------- ------------------- P1 14400.00 13680.00 15120.00 34.5 3.532 25.60013 1824. S1 118.40 10.0 208.330 .00253 1118. 1.3 S2 117.91 10.0 208.330 .00439 1118. 1.8

F.L. N.L. FLUX DENS. 16.706 16.836 LEAKAGE INDUCTAN CE MHYS 245.843 CORE LOSS 105.561 108.891 POWER FACTOR 1.0000 COIL LOSS 779.995 .008 IMPEDANCE % 2.70 EXCIT. VA 219.090 238.628 EFFICIENCY % 98.26 EXCIT. CURR. .015 .017 TANK OIL GAL 41.23
AMBIENT TEMP. 20.00 NOMINAL LENGT H 13.24 TEMP.RISE 65.00 NOMINAL DEPT H 16.98 OPERATING TEMP. 85.00 NOMINAL HEIGH T 10.94

2 COND. I R LOSS = 758.5084 COND. EDDY CURRENT LOSS = 2.5240 OTHER STRAY LOSS = 18.9627 K VALUE = 1.00005-61

%LOAD %REG %EFF %IR %IX %IZ CO IL LOSS TEMP. RISE

--------------------------------------------------- --------------------- 25 .33 98.81 .313 .565 .646 41.814 21.3 35 .47 98.92 .446 .791 .908 83.412 26.5 50 .69 98.88 .663 1.130 1.310 176.975 37.5 65 .95 98.72 .907 1.471 1.728 314.794 52.2 75 1.15 98.58 1.088 1.700 2.018 435.534 64.2 100 1.55 98.26 1.461 2.273 2.702 779.984 65.0 125 1.96 97.92 1.832 2.851 3.389 1222.869 65.0

Table 5.6.2 provides the bill of materials that was calculated from the OPS design details report. This bill of materials uses the raw materi al prices given in this Chapter for fixed and variable materials used in building the transformer . These materials are then marked up at the bottom of the table to arrive at the manufacturer’s selling price. This table provides the bill of materials for an evaluated transformer from design line 1, a 50kVA single-phase, liquid-immersed, pad-mount M3 design, with a copper primary and an a luminum secondary. The Department generated this design using a $1.50 A and a $0.38 B

.5-62

Bill of Materials and Labor for liquid-immersed, si ngle-phase, pad-mount, 50kVA A$ Input $1.50 B$ Input $0.38 Efficiency at 50% load 98.87%

Material item Type quantity $ each $ total Core steel* (lb) M3-.009 188 0.80 $ 150.79

$ Primary winding* (lb) Copper wire, formvar, round #1 0-20 45 1.55 $ 70.29

$ Secondary windings* (lb) Aluminum strip, thickness r ange 0.02-0.045 21 1.54 $ 32.52

$ Winding form & insulation* (lb) Kraft insulating pap er with diamond adhesive 4 1.59 $ 6.98

$ Oil (gal) - 41 1.71 $ 70.50

$ Tank

- 1 131.88 $ 131.88

$ Core clamp - 1 15.00 $ 15.00

$ Nameplate - 1 0.65 $ 0.65

$ Bushings HV & LV 1 34.00 $ 34.00

$ Misc. hardware - 1 10.00 $ 10.00

$ Scrap factor 1.0% 2.61 $ Total Material Cost 525.22 $

Labor item hours rate $ total Lead dressing 0.50 42.77 21.39 $ Inspection 0.10 42.77 4.28 $ Baking coils 0.10 42.77 4.28 $ Tanking and impregnating 0.50 42.77 21.39 $ Preliminary test 0.10 42.77 4.28 $ Final test 0.15 42.77 6.42 $ Pallet loading 0.27 42.77 11.55 $ Marking and miscellaneous 0.28 42.77 11.98 $ Winding the primary 0.20 42.77 8.62 $ Winding the secondary 0.48 42.77 20.53 $ Cutting, forming, and annealing 0.55 42.77 23.41 $ Core assembly 0.26 42.77 11.23 $ Handling and slitting factor (on material) 1.50% 3.91 $ Total Labor 3.491 42.77 153.24 $ Manufacturing Cost (Material + Labor) 678.46 $ Factory Overhead (Materials only) 12.5% 65.65 $ Non-production Cost Markup 25.0% 186.03 $ Manufacturer Selling Price 930.14 $ * indicates those items to which the scrap factor ( 1.0%) and the handling and slitting factor (1.5%) a re applied.
This bill of materials is based on non-rounded core dimensions. Table 5.6.2 Bill of Materials for Evaluated Transfor mer from Design Line 15-63

Figure 5.6.2 provides a summary of the costs contri buting to the total selling price of the evaluated transformer from design line 1. For this design, approximately 57 percent of the final manufacturer selling price is direct material and s crap. Labor accounts for 16 percent of the price and, together, the factory overhead and selling pri ce account for 27 percent.

5.6.3 Design Details Report for Non-Evaluated Transf ormer from Design Line 12 The following design report provides information onone of several designs DOE prepared to study the representative unit from design line 1 2. This is a 1500kVA, three-phase, mediumvoltage, dry-type unit at 95kV BIL. The design sho wn here (out of the 2,590 designs in the database) is for M6 core steel with aluminum primar y and secondary windings, and a $0.00 A and a $0.00 B.

OPTIMIZED PROGRAM SERVICE
CLEVELAND OHIO 101800 2005- 3-12 12:58: 9 STRIP CRUC 3-PHASE TYPE TRANSFORMER L12M6ALAL
FREQUENCY 60.0 MVA RATING 1.50 @ 100.00% DUTY CYCLE
CORE 9.929" CRUC STACK 9.929 GRADE M 6 THICKNESS .0140
WINDOW: 14.442 X 50.208 EFF. AREA 75.247 WEIGHT 5565.141
WINDING FORM:INS. DIM. 10.457 X 10.457 THICKNESS .156 LENGTH 48.208 Core/Coils 27%

Other Material 30% Labor 16% Factory Overhead 7% Selling Factor

20%

Figure 5.6.2 Manufacturer Selling Price Breakdown, E valuated

Transformer from Design Line 15-64

COIL SPECIFICATIONS

-------------------
WNDG WIRE LENGTH MEAN TURN S MARGIN WT

--------------------------------------------------- ------------------- S1 2X 1(.0167X38.2076) AL 46.38 42.8 2 5.000 69.450 P1 1X 2(.0668X .2318) AL 3407.39 66.5 7 5.750 116.001
NUMBER OF COILS 3 TOTAL BARE CONDUC TOR WEIGHT 556.355 WNDG TURNS LO TAP HI TAP LAYRS T/L LAYR INS SEC. INS BUILD

--------------------------------------------------- ------------------- S1 13.0 13 1.0 1(.01000) 1(.20000) 2.805 P1 585.0 555.8 614.3 15 1.0 1(.00001) 1(.00001) 1.182

TOT AL BUILD(%) 84.56
WNDG TAPS: TURNS( VOLTS)

--------------------------------------------------- ------- P1 570.4( 12158.25) 599.6( 12781.75) 614.3( 13093.50)

DISK INFORMATION

----------------- WNDG DISK WIDTH VOLTS/DISK BREAK TAPS SPAC E

--------------------------------------------------- ---- P1 42 .493 311.750 .750 2(.50) 38( . 375)

WNDG INTERNAL DUCTS( 90.00) %EFF EXTERNAL DUCTS ( 90.00) %EFF

--------------------------------------------------- ------------- S1 3 .750 X .750 IN. FULL P1 2 .750 X .750 IN. FULL

WNDG INT. DUCT AREA EXT. DUCT AREA TOTAL DUC T AREA

--------------------------------------------------- ------ S1 6800.8820 1617.2770 8418 .1580 P1 .0000 2519.9360 5176 .6380

ELECTRICAL ANALYSIS

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

--------------------------------------------------- ------------------- P1 12470.00 D 11846.50 13093.50 18.0 40.735 1.56703 1402. S1 273.07 W 4.0 1804.300 .00049 1412. 1.4

F.L. N.L. FLUX DENS. 16.320 16.472 LEAKAGE INDUCTAN CE MHYS 45.571 CORE LOSS 4645.135 4734.112 POWER FACTOR 1.0000 COIL LOSS 19994.840 .493 IMPEDANCE % 5.76 EXCIT. VA 8824.361 9869.501 EFFICIENCY % 98.38 EXCIT. CURR. .236 .264 OPEN ALT. DUCT 3 .00
AMBIENT TEMP. 20.00 NOMINAL LENGT H 73.11 TEMP.RISE 141.46 NOMINAL DEPT H 22.49 OPERATING TEMP. 161.46 NOMINAL HEIGH T 70.065-65

CRUCIFORM PLATE WIDTHS
W1 W2 W3 W4 W5 9.929 8.843 7.394 5.579 3.281

STACK HEIGHTS
H1 H2 H3 H4 H5 3.283 1.149 .907 .725 .542
RESULTANT GROSS AREA: 77.977 CIRCLE AREA F ILL: % 90.8
MIN. WINDING FORM INSIDE DIAMETER: 10.457
WINDING: S1 P1
TEMP RISE: 141. 116.

2 COND. I R LOSS = 19188.2900 COND. EDDY CURRENT LOSS = 39.0233 OTHER STRAY LOSS = 767.5314 K VALUE = 1.0000

TEMP. AT LOW TAP

---------------- S1 141.46 P1 121.72

WIRE WRAP PER COIL WNDG THICKNESS WEIGHT

------------------------- P1 .00600 8.72106

o AT REFERENCE TEMP. 170.0

---------------------------- COIL LOSS = 20441.770 IMPEDANCE % = 5.763

%LOAD %REG %EFF %IR %IX %IZ CO IL LOSS TEMP. RISE

--------------------------------------------------- --------------------- 25 .25 98.51 .241 1.402 1.423 944.956 47.0 35 .36 98.76 .344 1.958 1.988 1890.136 54.1 50 .55 98.85 .514 2.794 2.841 4033.891 68.2 65 .78 98.79 .708 3.634 3.702 7212.068 86.3 75 .94 98.71 .852 4.196 4.282 10014.870 100.3 100 1.44 98.38 1.275 5.612 5.755 19994.840 141.5 125 2.08 97.91 1.805 7.048 7.275 35411.180 190.8

Table 5.6.3 provides the bill of materials that was calculated from the OPS design details report. This bill of materials uses the raw materi al prices given in this Chapter for fixed and variable materials used in building the transformer . These materials are then marked up at the bottom of the table to arrive at the manufacturer’s selling price. This table provides the bill of materials for a non-evaluated transformer from desi gn line 12, a 1500kVA three-phase, medium-5-66

voltage, dry-type design with M6 core steel and an aluminum primary and secondary. The Department generated this design using a $0.00 A an d a $0.00 B.

Bill of Materials and Labor for medium voltage, dry -type, 3-phase, 1500kVA A$ Input $0.00 B$ Input $0.00 Efficiency at 50% load 98.81%

Material item Type quantity $ each $ total Core steel* (lb) M6-.014 5565 0.70 $ 3,895.60

$ Primary winding* (lb) Aluminum wire, rectangular 0.1 x 0.2, Nomex wrapped 348 2.06 $ 715.95

$ Secondary winding* (lb) Aluminum strip, thickness ra nge 0.02-0.045 208 1.54 $ 321.35

$ Winding form & insulation* (lb) Nomex insulation 110 1 8.11 $ 1,997.39

$ Enclosure 12-gauge steel 1 748.06 $ 748.06

$ Core clamp - 1 125.00 $ 125.00

$ Nameplate - 1 0.65 $ 0.65

$ LV buss bar (ft.) - 16 12.00 $ 192.00

$ HV tap board - 3 9.00 $ 27.00

$ HV terminals - 1 135.00 $ 135.00

$ Winding combs (lb.) - 70 10.24 $ 717.80

$ Duct spacers (ft.) 1318 0.56 $ 738.24

$ Impregnation (gal.) - 25 17.80 $ 443.74

$ Misc. hardware - 1 54.00 $ 54.00

$ Scrap factor 1.0% 69.30 $ Additional scrap on core** 4.0% 155.82 $ Total Material Cost 10,336.91 $

Labor item hours rate $ total Lead dressing 1.00 42.77 42.77 $ Inspection 0.25 42.77 10.69 $ Preliminary test 0.50 42.77 21.39 $ Final test 0.75 42.77 32.08 $ Packing 2.00 42.77 85.54 $ Enclosure manufacturing 8.00 42.77 342.16 $ Marking and miscellaneous 2.20 42.77 94.09 $ Winding the primary 23.03 42.77 985.18 $ Winding the secondary 2.93 42.77 125.10 $ Core stacking 7.94 42.77 339.73 $ Core assembly 6.00 42.77 256.62 $ Handling and Slitting Factor (on material) 1.50% 103.95 $ Total Labor 54.603 42.77 2,439.31 $ Manufacturing Cost (Material + Labor) 12,776.21 $ Factory Overhead (Materials only) 12.5% 1,292.11 $ Non-production Cost Markup 25.0% 3,517.08 $ Manufacturer Selling Price 17,585.41 $ * indicates those items to which the scrap factor ( 1.0%) and the handling and slitting factor (1.5%) a re applied. ** additional scrap on core due to mitering process

. This bill of materials is based on non-rounded core dimensions. Table 5.6.3 Bill of Materials for Non-Evaluated Tran sformer from Design Line 125-67

Figure 5.6.3 provides a summary of the costs contri buting to the total selling price of the non-evaluated transformer from design line 12. For this design, approximately 59 percent of the final manufacturer selling price is direct material and scrap. Labor accounts for 14 percent of the price and, together, the factory overhead and selli ng price account for 27 percent.

5.6.4 Design Details Report for Evaluated Transforme r from Design Line 12 A design specification report for a 1500kVA three-p hase, medium-voltage, dry-type transformer appears below. This design incorporate s M3 core steel, with copper primary and secondary windings. The evaluation factors for thi s design are $0.50 A and $0.08 B. The bill of materials and associated breakdown of costs for thi s design are also reported, after the design and electrical analysis reports.

OPTIMIZED PROGRAM SERVICE
CLEVELAND OHIO 101800 2005- 3-12 19:22:57 STRIP CRUC 3-PHASE TYPE TRANSFORMER L12M3CUCU
FREQUENCY 60.0 MVA RATING 1.50 @ 100.00% DUTY CYCLE
CORE 9.936" CRUC STACK 9.936 GRADE M 3 THICKNESS .0090
WINDOW: 13.354 X 50.940 EFF. AREA 74.572 WEIGHT 5550.538
WINDING FORM:INS. DIM. 10.464 X 10.464 THICKNESS .156 LENGTH 48.940

COIL SPECIFICATIONS

-------------------
WNDG WIRE LENGTH MEAN TURN S MARGIN WT

--------------------------------------------------- ------------------- S1 2X 1(.0096X38.9404) CU 45.72 42.2 0 5.000 129.011 P1 1X 2(.0512X .1778) CU 3301.91 64.5 1 5.750 226.486 Core/Coils 28%

Other Material 31% Labor 14% Factory Overhead 7% Selling Factor

20%

Figure 5.6.3 Manufacturer Selling Price Breakdown, N on-Evaluated

Transformer from Design Line 125-68

NUMBER OF COILS 3 TOTAL BARE CONDUC TOR WEIGHT 1075.046 WNDG TURNS LO TAP HI TAP LAYRS T/L LAYR INS SEC. INS BUILD

--------------------------------------------------- ------------------- S1 13.0 13 1.0 1(.01000) 1(.20000) 2.620 P1 585.0 555.8 614.3 15 1.0 1(.00001) 1(.00001) .948

TOT AL BUILD(%) 85.20
WNDG TAPS: TURNS( VOLTS)

--------------------------------------------------- ------- P1 570.4( 12158.25) 599.6( 12781.75) 614.3( 13093.50)

DISK INFORMATION

----------------- WNDG DISK WIDTH VOLTS/DISK BREAK TAPS SPAC E

--------------------------------------------------- ---- P1 42 .510 311.750 .750 2(.50) 38( . 375)

WNDG INTERNAL DUCTS( 90.00) %EFF EXTERNAL DUCTS ( 90.00) %EFF

--------------------------------------------------- ------------- S1 3 .750 X .750 IN. FULL P1 2 .750 X .750 IN. FULL

WNDG INT. DUCT AREA EXT. DUCT AREA TOTAL DUC T AREA

--------------------------------------------------- ------ S1 6962.6350 1621.1610 8583 .7960 P1 .0000 2516.7880 4898 .1040

ELECTRICAL ANALYSIS

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

--------------------------------------------------- ------------------- P1 12470.00 D 11846.50 13093.50 18.0 40.680 1.51120 2286. S1 273.23 W 4.0 1804.300 .00050 2411. 1.4

F.L. N.L. FLUX DENS. 16.477 16.622 LEAKAGE INDUCTAN CE MHYS 44.500 CORE LOSS 3261.498 3377.035 POWER FACTOR 1.0000 COIL LOSS 19285.360 .285 IMPEDANCE % 5.61 EXCIT. VA 7133.554 7726.391 EFFICIENCY % 98.52 EXCIT. CURR. .191 .207 OPEN ALT. DUCT 3 .00
AMBIENT TEMP. 20.00 NOMINAL LENGT H 69.87 TEMP.RISE 138.10 NOMINAL DEPT H 21.58 OPERATING TEMP. 158.10 NOMINAL HEIGH T 70.81

CRUCIFORM PLATE WIDTHS
W1 W2 W3 W4 W5 9.936 8.849 7.399 5.583 3.284

STACK HEIGHTS5-69

H1 H2 H3 H4 H5 3.285 1.150 .907 .726 .542
RESULTANT GROSS AREA: 78.085 CIRCLE AREA F ILL: % 90.8
MIN. WINDING FORM INSIDE DIAMETER: 10.465
WINDING: S1 P1
TEMP RISE: 138. 117.

2 COND. I R LOSS = 18519.0200 COND. EDDY CURRENT LOSS = 25.5813 OTHER STRAY LOSS = 740.7608 K VALUE = 1.0000

TEMP. AT LOW TAP

---------------- S1 138.10 P1 122.59

WIRE WRAP PER COIL WNDG THICKNESS WEIGHT

------------------------- P1 .00600 6.62868

o AT REFERENCE TEMP. 170.0

---------------------------- COIL LOSS = 19877.280 IMPEDANCE % = 5.620

%LOAD %REG %EFF %IR %IX %IZ CO IL LOSS TEMP. RISE

--------------------------------------------------- --------------------- 25 .24 98.88 .232 1.364 1.384 907.508 41.9 35 .35 99.03 .332 1.907 1.935 1818.703 49.2 50 .53 99.05 .497 2.723 2.768 3887.590 63.8 65 .75 98.96 .684 3.542 3.608 6955.772 82.2 75 .91 98.86 .823 4.091 4.173 9660.987 96.4 100 1.39 98.52 1.231 5.473 5.610 19285.400 138.1 125 2.00 98.05 1.742 6.873 7.090 34129.490 187.9
Table 5.6.4 provides the bill of materials that was calculated from the OPS design details report. This bill of materials uses the raw materi al prices given in this Chapter for fixed and variable materials used in building the transformer . These materials are then marked up at the bottom of the table to arrive at the manufacturer’s selling price. This table provides the bill of materials for an evaluated transformer from design line 12, a 1500kVA three-phase, mediumvoltage, dry-type transformer built with M3 core st eel and copper primary and secondary windings. The Department generated this design using a $0.50 A and a $0.08 B.5-70

Bill of Materials and Labor for medium voltage, dry -type, 3-phase, 1500kVA A$ Input $0.50 B$ Input $0.08 Efficiency at 50% load 99.02%

Material item Type quantity $ each $ total Core steel* (lb) M3-.009 5551 0.80 $ 4,440.43

$ Primary winding* (lb) Copper wire, rectangular 0.1 x 0.2, Nomex wrapped 679 2.00 $ 1,361.68

$ Secondary winding* (lb) Copper strip, thickness rang e 0.02-0.045 387 2.32 $ 897.92

$ Winding form & insulation* (lb) Nomex insulation 110 1 8.11 $ 1,997.49

$ Enclosure 12-gauge steel 1 733.94 $ 733.94

$ Core clamp - 1 125.00 $ 125.00

$ Nameplate - 1 0.65 $ 0.65

$ LV buss bar (ft.) - 16 12.00 $ 192.00

$ HV tap board - 3 9.00 $ 27.00

$ HV terminals - 1 135.00 $ 135.00

$ Winding combs (lb.) - 62 10.24 $ 631.23

$ Duct spacers (ft.) - 1306 0.56 $ 731.11

$ Impregnation (gal.) - 23 17.80 $ 411.17

$ Misc. hardware - 1 54.00 $ 54.00

$ Scrap factor 1.0% 86.98 $ Additional scrap on core** 4.0% 177.62 $ Total Material Cost 12,003.20 $

Labor item hours rate $ total Lead dressing 1.00 42.77 42.77 $ Inspection 0.25 42.77 10.69 $ Preliminary test 0.50 42.77 21.39 $ Final test 0.75 42.77 32.08 $ Packing 2.00 42.77 85.54 $ Enclosure manufacturing 8.00 42.77 342.16 $ Marking and miscellaneous 2.20 42.77 94.09 $ Winding the primary 23.03 42.77 985.18 $ Winding the secondary 2.93 42.77 125.10 $ Core stacking 7.95 42.77 339.97 $ Core assembly 6.00 42.77 256.62 $ Handling and Slitting Factor (on material) 1.50% 130.46 $ Total Labor 54.608 42.77 2,466.05 $ Manufacturing Cost (Material + Labor) 14,469.25 $ Factory Overhead (Materials only) 12.5% 1,500.40 $ Non-production Cost Markup 25.0% 3,992.41 $ Manufacturer Selling Price 19,962.07 $ * indicates those items to which the scrap factor ( 1.0%) and the handling and slitting factor (1.5%) a re applied. ** additional scrap on core due to mitering process

. This bill of materials is based on non-rounded core dimensions. Table 5.6.4 Bill of Materials for Evaluated Transfor mer from Design Line 125-71

Figure 5.6.4 provides a summary of the costs contri buting to the total selling price of the evaluated transformer from design line 12. For thi s design, approximately 60 percent of the final manufacturer selling price is direct material and s crap. Labor accounts for 12 percent of the price and, together, the factory overhead and selling pri ce account for 28 percent.

5.7 TEAR-DOWN ANALYSIS

The Department purchased, tested, disassembled, and analyzed six transformers from design line 7 for the engineering analysis. Although this technical support document (TSD) does not contain analysis results for design line 7 due to p assage of the Energy Policy Act of 2005, this teardown analysis is important for two reasons: 1) to d emonstrate the predictive accuracy of the OPS software, and 2) to validate the NOPR designs. The Department selected design line 7 because this design line has the largest energy savings potentia l and because the representative unit (75 kVA three-phase, low-voltage, dry-type) is readily avai lable from wholesale distributors. This section discusses the tear-down analysis on the six transfo rmers and the results. The Department purchased six transformers in early 2004—two ‘matched pairs’ from three manufacturers. The two transformers from each manu facturer represented a low-first-cost unit and a NEMA TP-1/Energy Star unit. The transformers wer e shipped directly to the testing facility, Transformer Engineering Corporation (TEC) in Clevel and, Ohio. TEC has been a manufacturer of custom-designed transformers, inductors, and other electro-magnetic components since 1937. TEC has a 50,000-square-foot facility in Cleveland, whi ch includes a top-notch testing laboratory. Core/Coils 33%

Other Material 27% Labor 12% Factory Overhead 8% Selling Factor

20%

Figure 5.6.4 Manufacturer Selling Price Breakdown, E valuated

Transformer from Design Line 125-72

The Department reviewed several manufacturer catalo gues and identified matched pairs of low-first-cost and NEMA TP-1 units. It purchased t hese units from a local distributor, and shipped them to TEC for testing. In Cleveland, the transfo rmers were subjected to the following tests:
• Core loss test • Conductor resistance test • Conductor loss test • Temperature test The Department recorded data for each of these test s, documenting all the critical performance metrics for each of the six designs. I t then carefully disassembled the transformers, paying attention to the construction techniques, in cluding type of steel and conductor. The Department weighed all the pieces, and recorded phy sical attributes, such as core dimensions and number of turns. It then put all of these physical dimensions into the OPS software, to model the transformer that had just been disassembled. The O PS software used its electrical analysis program to predict the values that had been measured in the laboratory. This step validated the predictive capability of the software for generating performan ce metrics associated with its modeled designs. The OPS software accurately predicted the efficienc y (including the core and coil losses), the impedance, the inductance, and all the transformer performance metrics. Once the NOPR engineering analysis designs were com pleted, the Department used the results of the tear-down analysis to create a manuf acturer’s selling price. In other words, using measured variables such as the pounds of core steel and pounds of conductor, the Department costed out the torn-down units using the same 2000–2004 av erage material prices and mark-ups, just as it had done for the engineering analysis. The Departm ent then plotted these six dots on the NOPR manufacturer’s selling price-efficiency curve gener ated for design line 7. Figure 5.7.1 presents the plot of these torn-down units. The six transformer tear-downs align perfectly with the design line 7 cost-efficiency curve.5-73 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000

94.50% 95.00% 95.50% 96.00% 96.50% 97.00% 97.50% 98.00% 98. 50% 99.00% 99.50% Efficiency at 35% loadManfacturer Selling Price ($) M36AlAl_bl M19AlAl_bl M6AlAl_bl M6AlAl_mtt M6AlAl_mtf M4CuAl_mtf M3CuCu_mtf HOCuCu_mtf Teardowns TP-1: 98.0%

Manufacturer A: Low Eff M36_bl Manufacturer B: Low Eff M19_bl

Manufacturer C: Low Eff M36_bl Manufacturer B:

High Eff M6_bl Manufacturer C: High Eff M5_mt Manufacturer A:

High Eff M6_mt

Figure 5.7.1 Tear-down Plot Comparison, Design Line 7, 75kVA Three-phase Dry-type