APPENDIX 5D. RESULTS OF THE VOLTAGE SENSITIVITY ANALYSIS 

TABLE OF CONTENTS 

5D.1 INTRODUCTION ................................................................................................................. 2 

5D.2 Graphical Results of the Voltage Sensitivity Runs................................................................ 3 

5D.3 Tabular Review of the Voltage Sensitivity Run Results ....................................................... 7 

LIST OF TABLES 

Table 5D.1 Baseline and Sensitivity Voltages for Design Lines Analyzed ....................................2 

Table 5D.2 Results of Voltage Sensitivity for Design Line 2, M3CuAl .........................................8 

Table 5D.3 Results of Voltage Sensitivity for Design Line 2, M2CuCu ........................................8 

Table 5D.4 Results of Voltage Sensitivity for Design Line 3, M3CuAl .........................................9 

Table 5D.5 Results of Voltage Sensitivity for Design Line 3, M2CuCu ......................................10 

Table 5D.6 Results of Voltage Sensitivity for Design Line 4, M3CuAl .......................................10 

Table 5D.7 Results of Voltage Sensitivity for Design Line 4, M2CuCu ......................................11 

Table 5D.8 Results of Voltage Sensitivity for Design Line 5, M3CuAl .......................................12 

Table 5D.9 Results of Voltage Sensitivity for Design Line 5, M2CuCu ......................................12 

LIST OF FIGURES 

Figure 5D.1 Engineering Analysis Results for DL2 M3CuAl Voltage Sensitivity........................3 

Figure 5D.2 Engineering Analysis Results for DL2 M2CuCu Voltage Sensitivity .......................4 

Figure 5D.3 Engineering Analysis Results for DL3 M3CuAl Voltage Sensitivity........................4 

Figure 5D.4 Engineering Analysis Results for DL3 M2CuCu Voltage Sensitivity .......................5 

Figure 5D.5 Engineering Analysis Results for DL4 M3CuAl Voltage Sensitivity........................5 

Figure 5D.6 Engineering Analysis Results for DL4 M2CuCu Voltage Sensitivity .......................6 

Figure 5D.7 Engineering Analysis Results for DL5 M3CuAl Voltage Sensitivity........................6 

Figure 5D.8 Engineering Analysis Results for DL5 M2CuCu Voltage Sensitivity .......................7 

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 EE-RM/STD-00-550 COMMENT 196
APPENDIX 5D. RESULTS OF THE VOLTAGE SENSITIVITY ANALYSIS 

5D.1 INTRODUCTION 

In response to the notice of proposed rulemaking (NOPR), stakeholders expressed 

concern that if the DOE set the standard level too high, it might eliminate certain voltage classes 

from the market. DOE understands that it selected common voltages as its baseline units for 

evaluation in the engineering analysis, but that there are other voltages that may not be common, 

but are specified in distribution networks in the United States. Therefore, DOE conducted a 

sensitivity analysis on its engineering analysis by considering certain other voltage classes with 

higher BIL ratings relative to the baseline units being studied. As the BIL rating increases, so 

manufacturers must add more insulation around the windings, increasing the distance of the 

magnetic flux pathway, and thereby increasing losses. DOE understands that all else held equal, 

distribution transformers with higher BIL ratings will have lower resulting efficiency values. 

This appendix contains the summary of the results of the sensitivity analysis conducted 

on the voltages with higher BIL ratings for certain liquid-immersed design lines. This issue was 

not evaluated for medium-voltage dry-type distribution transformers, because DOE already 

created product classes that grouped medium-voltage dry-type transformers by insulation class. 

That is, DOE grouped medium-voltage dry-type transformers with ratings of 20 to 45 BIL in one 

class, ratings of 46 to 95 BIL in second class and 96 and higher BIL in a third class. 

The following table identifies exactly which liquid-immersed voltages were used in the 

reference case and which were used in the sensitivity case. 

Table 5D.1 Baseline and Sensitivity Voltages for Design Lines Analyzed 

Design 

Line 

Baseline Conditions Voltage Sensitivity 

Primary Voltage Secondary 

Voltage 

Primary Voltage Secondary 

Voltage 

DL2 14400 240/120V 34500GRDY/19920 

(150kV BIL) 

240/120V 

DL3 14400 277/120V 34500GRDY/19920 

(150kV BIL) 

277V 

DL4 12470Y/7200 208Y/120V 34500GRDY/19920 

(150kV BIL) 

208Y/120V 

DL5 24940GRDY/14400 408Y/277V 34500GRDY/19920 

(150kV BIL) 

208V 

Changing only the voltages as shown in the table above, two engineering analyses were 

conducted at each sensitivity – one using M3CuAl and one using M2CuCu. These two design 

option combinations were selected because of the broad range of efficiencies they encompassed, 

and because they represent the highest efficiency level that can be achieved with conventional 

core steel. Other than changing the voltages, these two design option combinations were treated 

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 EE-RM/STD-00-550 COMMENT 196
in exactly the same way as all the other design option combinations analyzed for the engineering 

analysis. The approach used by DOE in conducting this analysis is discussed in detail in TSD 

Chapter 5. 

5D.2 GRAPHICAL RESULTS OF THE VOLTAGE SENSITIVITY RUNS 

This section of the appendix presents a series of graphs which depict graphically the 

results of the sensitivity analysis. These graphs illustrate the impact of the voltage sensitivity 

analysis, causing the efficiency curve to shift up (more expensive) and to the left (less efficient). 

There are eight graphs in this section, presenting the two design option combinations for each of 

the four voltage sensitivity cases separately. 

Pri l

l

itivi l

$500 

$700 

$900 

$1,100 

$1,300 

$1,500 

$1,700 

DL2 Reference 

DL2 Voltage Sensitivity 

mary Vo tages: 

Reference:14400 Vo ts 

Sens ty: 34500GRDY/19920 Vo ts-150 BIL 

98.40% 98.50% 98.60% 98.70% 98.80% 98.90% 99.00% 99.10% 99.20% 

Figure 5D.1 Engineering Analysis Results for DL2 M3CuAl Voltage Sensitivity 

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5D-4

$600

$800

$1,000

$1,200

$1,400

$1,600

$1,800

98.20% 98.40% 98.60% 98.80% 99.00% 99.20% 99.40%

DL2 Reference

DL2 Voltage Sensitivity

Primary Voltages:

Reference:14400 Volts

Sensitivity: 34500GRDY/19920 Volts-150 BIL

Figure 5D.2 Engineering Analysis Results for DL2 M2CuCu Voltage Sensitivity 

$3,000

$4,000

$5,000

$6,000

$7,000

$8,000

$9,000

$10,000

$11,000

$12,000

99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60%

DL3 Reference

DL3 Voltage Sensitivity

Primary Voltages:

Reference:14400 Volts

Sensitivity: 34500GRDY/19920 Volts-150 BIL

Figure 5D.3 Engineering Analysis Results for DL3 M3CuAl Voltage Sensitivity 

 EE-RM/STD-00-550 COMMENT 196
5D-5

$4,000

$5,000

$6,000

$7,000

$8,000

$9,000

$10,000

99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% 99.70%

DL3 Reference

DL3 Voltage Sensitivity

Primary Voltages:

Reference:14400 Volts

Sensitivity: 34500GRDY/19920 Volts-150 BIL

Figure 5D.4 Engineering Analysis Results for DL3 M2CuCu Voltage Sensitivity 

$2,000

$2,500

$3,000

$3,500

$4,000

$4,500

$5,000

$5,500

$6,000

98.20% 98.40% 98.60% 98.80% 99.00% 99.20% 99.40%

DL4 Reference

DL4 Voltage Sensitivity

Primary Voltages:

Reference:12470Y/7200 Volts

Sensitivity: 34500GRDY/19920 Volts-150 BIL

Figure 5D.5 Engineering Analysis Results for DL4 M3CuAl Voltage Sensitivity 

 EE-RM/STD-00-550 COMMENT 196
5D-6

$2,000

$2,500

$3,000

$3,500

$4,000

$4,500

$5,000

$5,500

$6,000

$6,500

$7,000

98.40% 98.50% 98.60% 98.70% 98.80% 98.90% 99.00% 99.10% 99.20% 99.30% 99.40%

DL4 Reference

DL4 Voltage Sensitivity

Primary Voltages:

Reference:12470Y/7200 Volts

Sensitivity: 34500GRDY/19920 Volts-150 BIL

Figure 5D.6 Engineering Analysis Results for DL4 M2CuCu Voltage Sensitivity 

$-

$5,000

$10,000

$15,000

$20,000

$25,000

$30,000

$35,000

$40,000

99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60%

DL5 Reference

DL5 Voltage Sensitivity

Primary Voltages:

Reference: 24940GRDY/14400 Volts

Sensitivity: 34500GRDY/19920 Volts-150 BIL

Figure 5D.7 Engineering Analysis Results for DL5 M3CuAl Voltage Sensitivity 

 EE-RM/STD-00-550 COMMENT 196
$40,000 

$35,000 

$30,000 

$25,000 

$20,000 

$15,000 

$10,000 

$5,000 

$-

l itivi

i l

/ l

itivi / l

DL5 Reference 

DL5 Vo tage Sens ty 

Pr mary Vo tages: 

Reference: 24940GRDY 14400 Vo ts 

Sens ty: 34500GRDY 19920 Vo ts-150 BIL 

99.00% 99.10% 99.20% 99.30% 99.40% 99.50% 99.60% 99.70% 

Figure 5D.8 Engineering Analysis Results for DL5 M2CuCu Voltage Sensitivity 

5D.3 TABULAR REVIEW OF THE VOLTAGE SENSITIVITY RUN RESULTS 

This section of the appendix presents a numerical evaluation of the results conducted for 

the voltage sensitivity runs. The tables provide a more detailed look at the impact of the voltage 

sensitivity run at each of the trial standard levels (TSLs). 

The following table presents the results for the voltage sensitivity analysis conducted on 

design line 2, a 25 kVA single-phase pole-mount liquid-immersed distribution transformer. This 

transformer using the M3CuAl design option combination. The voltage sensitivity analysis 

found an average increase in price of approximately 12.2% and a reduction in efficiency of 0.14, 

meaning a design that had otherwise been 99.00 percent efficient, would now be 98.86 percent 

efficient. If the efficiency value is outside the range of available designs for this voltage 

sensitivity analysis, that cell in the table is marked with an ‘n/a’. 

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Table 5D.2 Results of Voltage Sensitivity for Design Line 2, M3CuAl 

DL2 TSL Change 

in MSP* 

Change in 

Efficiency 

Baseline Voltage 

MSP 

Sensitivity 

Voltage MSP 

Sensitivity Voltage 

Efficiency 

[%] [%] [%] [$] [$] [%] 

TSL1 98.70 12.2% n/a $664.99 $746.05 n/a 

TSL2 98.73 9.1% n/a $676.15 $737.62 n/a 

TSLD 98.79 11.6% (0.20) $704.44 $786.40 98.59 

TSLC 98.91 13.0% (0.12) $788.60 $891.47 98.79 

TSLB 98.91 13.0% (0.12) $788.60 $891.47 98.79 

TSL3 98.76 11.6% n/a $684.06 $763.37 n/a 

TSL4 98.79 11.6% (0.20) $704.44 $786.40 98.59 

TSLA 99.04 13.6% (0.06) $979.28 $1,112.92 98.98 

TSL5 98.96 13.6% (0.11) $827.94 $940.48 98.85 

TSL6 99.46 n/a n/a n/a n/a n/a 

Average 12.2% (0.14) 

* MSP is an abbreviation for the Manufacturer’s Selling Price. 

The following table presents the results for the voltage sensitivity analysis conducted on 

design line 2, a 25 kVA single-phase pole-mount liquid-immersed distribution transformer. This 

transformer using the M2CuCu design option combination. The voltage sensitivity analysis 

found an average increase in price of approximately 5.6% and a reduction in efficiency of 0.12, 

meaning a design that had otherwise been 99.00 percent efficient, would now be 98.88 percent 

efficient. 

Table 5D.3 Results of Voltage Sensitivity for Design Line 2, M2CuCu 

DL2 TSL Change 

in MSP* 

Change in 

Efficiency 

Baseline Voltage 

MSP 

Sensitivity 

Voltage MSP 

Sensitivity Voltage 

Efficiency 

[%] [%] [%] [$] [$] [%] 

TSL1 98.70 4.7% (0.11) $717.90 $751.54 98.59 

TSL2 98.73 6.2% (0.14) $716.52 $761.09 98.59 

TSLD 98.79 6.8% (0.15) $735.30 $785.38 98.64 

TSLC 98.91 5.0% (0.14) $797.37 $837.16 98.77 

TSLB 98.91 5.0% (0.14) $797.37 $837.16 98.77 

TSL3 98.76 5.0% (0.15) $731.78 $768.72 98.61 

TSL4 98.79 6.8% (0.15) $735.30 $785.38 98.64 

TSLA 99.04 7.4% (0.04) $1,005.48 $1,080.35 99.00 

TSL5 98.96 3.8% (0.04) $854.06 $886.67 98.92 

TSL6 99.46 n/a n/a n/a n/a n/a 

Average 5.6% (0.12) 

* MSP is an abbreviation for the Manufacturer’s Selling Price. 

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The following table presents the results for the voltage sensitivity analysis conducted on 

design line 3, a 500 kVA single-phase round-tank liquid-immersed distribution transformer. 

This transformer using the M3CuAl design option combination. The voltage sensitivity analysis 

found an average increase in price of approximately 7.0% and a reduction in efficiency of 0.03, 

meaning a design that had otherwise been 99.40 percent efficient, would now be 99.37 percent 

efficient. 

Table 5D.4 Results of Voltage Sensitivity for Design Line 3, M3CuAl 

DL3 TSL Change 

in MSP* 

Change in 

Efficiency 

Baseline Voltage 

MSP 

Sensitivity 

Voltage MSP 

Sensitivity Voltage 

Efficiency 

[%] [%] [%] [$] [$] [%] 

TSL1 99.30 2.4% (0.03) $4,296.35 $4,401.46 99.27 

TSL2 99.38 11.4% (0.01) $4,660.64 $5,191.34 99.37 

TSLD 99.38 11.4% (0.01) $4,660.64 $5,191.34 99.37 

TSLC 99.42 2.7% (0.03) $5,035.88 $5,169.82 99.39 

TSLB 99.47 4.4% (0.03) $5,581.20 $5,829.30 99.44 

TSL3 99.46 2.6% (0.04) $5,561.08 $5,708.29 99.42 

TSL4 99.54 14.0% (0.05) $7,022.08 $8,007.04 99.49 

TSLA 99.54 n/a n/a n/a n/a n/a 

TSL5 99.74 n/a n/a n/a n/a n/a 

TSL6 99.75 n/a n/a n/a n/a n/a 

Average 7.0% (0.03) 

* MSP is an abbreviation for the Manufacturer’s Selling Price. 

The following table presents the results for the voltage sensitivity analysis conducted on 

design line 3, a 500 kVA single-phase round-tank liquid-immersed distribution transformer. 

This transformer using the M2CuCu design option combination. The voltage sensitivity analysis 

found an average increase in price of approximately 4.9% and a reduction in efficiency of 0.04, 

meaning a design that had otherwise been 99.40 percent efficient, it would now be 99.36 percent 

efficient. 

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Table 5D.5 Results of Voltage Sensitivity for Design Line 3, M2CuCu 

DL3 TSL Change 

in MSP* 

Change in 

Efficiency 

Baseline Voltage 

MSP 

Sensitivity 

Voltage MSP 

Sensitivity Voltage 

Efficiency 

[%] [%] [%] [$] [$] [%] 

TSL1 99.30 4.4% (0.07) $4,455.54 $4,653.12 99.23 

TSL2 99.38 5.5% (0.04) $4,661.25 $4,916.02 99.34 

TSLD 99.38 5.5% (0.04) $4,661.25 $4,916.02 99.34 

TSLC 99.42 3.4% (0.06) $4,900.03 $5,067.81 99.36 

TSLB 99.47 6.0% (0.02) $5,479.85 $5,807.16 99.45 

TSL3 99.46 3.0% (0.04) $5,226.04 $5,383.42 99.42 

TSL4 99.54 6.4% (0.03) $6,510.92 $6,927.42 99.51 

TSLA 99.54 n/a n/a n/a n/a n/a 

TSL5 99.74 n/a n/a n/a n/a n/a 

TSL6 99.75 n/a n/a n/a n/a n/a 

Average 4.9% (0.04) 

* MSP is an abbreviation for the Manufacturer’s Selling Price. 

The following table presents the results for the voltage sensitivity analysis conducted on 

design line 4, a 150 kVA three-phase pad-mount liquid-immersed distribution transformer. This 

transformer using the M3CuAl design option combination. The voltage sensitivity analysis 

found an average increase in price of approximately 31.6% and a reduction in efficiency of 0.27, 

meaning a design that had otherwise been 99.20 percent efficient, it would now be 98.93 percent 

efficient. 

Table 5D.6 Results of Voltage Sensitivity for Design Line 4, M3CuAl 

DL4 TSL Change 

in MSP* 

Change in 

Efficiency 

Baseline Voltage 

MSP 

Sensitivity 

Voltage MSP 

Sensitivity Voltage 

Efficiency 

[%] [%] [%] [$] [$] [%] 

TSL1 98.90 24.4% (0.37) $2,868.06 $3,567.36 98.53 

TSL2 99.08 33.5% (0.21) $3,460.18 $4,617.82 98.87 

TSLD 99.08 33.5% (0.21) $3,460.18 $4,617.82 98.87 

TSLC 99.08 33.5% (0.21) $3,460.18 $4,617.82 98.87 

TSLB 99.08 33.5% (0.21) $3,460.18 $4,617.82 98.87 

TSL3 99.26 n/a (0.25) $4,757.38 n/a 99.01 

TSL4 99.26 n/a (0.25) $4,757.38 n/a 99.01 

TSLA 99.19 n/a (0.44) $4,086.81 n/a 98.75 

TSL5 99.58 n/a n/a n/a n/a n/a 

TSL6 99.61 n/a n/a n/a n/a n/a 

Average 31.6% (0.27) 

* MSP is an abbreviation for the Manufacturer’s Selling Price. 

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The following table presents the results for the voltage sensitivity analysis conducted on 

design line 4, a 150 kVA three-phase pad-mount liquid-immersed distribution transformer. This 

transformer using the M2CuCu design option combination. The voltage sensitivity analysis 

found an average increase in price of approximately 27.1% and a reduction in efficiency of 0.26, 

meaning a design that had otherwise been 99.20 percent efficient, it would now be 98.94 percent 

efficient. 

Table 5D.7 Results of Voltage Sensitivity for Design Line 4, M2CuCu 

DL4 TSL Change 

in MSP* 

Change in 

Efficiency 

Baseline Voltage 

MSP 

Sensitivity 

Voltage MSP 

Sensitivity Voltage 

Efficiency 

[%] [%] [%] [$] [$] [%] 

TSL1 98.90 18.7% (0.38) $2,949.41 $3,500.52 98.52 

TSL2 99.08 29.1% (0.28) $3,339.14 $4,312.37 98.80 

TSLD 99.08 29.1% (0.28) $3,339.14 $4,312.37 98.80 

TSLC 99.08 29.1% (0.28) $3,339.14 $4,312.37 98.80 

TSLB 99.08 29.1% (0.28) $3,339.14 $4,312.37 98.80 

TSL3 99.26 n/a (0.21) $4,434.48 n/a 99.05 

TSL4 99.26 n/a (0.21) $4,434.48 n/a 99.05 

TSLA 99.19 n/a (0.16) $4,009.14 n/a 99.03 

TSL5 99.58 n/a n/a n/a n/a n/a 

TSL6 99.61 n/a n/a n/a n/a n/a 

Average 27.1% (0.26) 

* MSP is an abbreviation for the Manufacturer’s Selling Price. 

The following table presents the results for the voltage sensitivity analysis conducted on 

design line 5, a 1500 kVA three-phase pad-mount liquid-immersed distribution transformer. 

This transformer using the M3CuAl design option combination. The voltage sensitivity analysis 

found an average increase in price of approximately 7.1% and a reduction in efficiency of 0.06, 

meaning a design that had otherwise been 99.40 percent efficient, it would now be 99.34 percent 

efficient. 

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Table 5D.8 Results of Voltage Sensitivity for Design Line 5, M3CuAl 

DL5 TSL Change 

in MSP* 

Change in 

Efficiency 

Baseline Voltage 

MSP 

Sensitivity 

Voltage MSP 

Sensitivity Voltage 

Efficiency 

[%] [%] [%] [$] [$] [%] 

TSL1 99.30 -0.2% 0.00 $12,682.26 $12,651.01 99.30 

TSL2 99.36 2.4% (0.07) $13,136.26 $13,455.19 99.29 

TSLD 99.42 8.0% (0.08) $13,905.54 $15,019.85 99.34 

TSLC 99.42 8.0% (0.08) $13,905.54 $15,019.85 99.34 

TSLB 99.47 11.8% (0.04) $17,643.58 $19,726.28 99.43 

TSL3 99.42 8.0% (0.08) $13,905.54 $15,019.85 99.34 

TSL4 99.47 11.8% (0.04) $17,643.58 $19,726.28 99.43 

TSLA 99.54 n/a n/a n/a n/a n/a 

TSL5 99.71 n/a n/a n/a n/a n/a 

TSL6 99.71 n/a n/a n/a n/a n/a 

Average 7.1% (0.06) 

* MSP is an abbreviation for the Manufacturer’s Selling Price. 

The following table presents the results for the voltage sensitivity analysis conducted on 

design line 5, a 1500 kVA three-phase pad-mount liquid-immersed distribution transformer. 

This transformer using the M2CuCu design option combination. The voltage sensitivity analysis 

found an average increase in price of approximately 16.9% and a reduction in efficiency of 0.08, 

meaning a design that had otherwise been 99.40 percent efficient, it would now be 99.32 percent 

efficient. 

Table 5D.9 Results of Voltage Sensitivity for Design Line 5, M2CuCu 

DL5 TSL Change 

in MSP* 

Change in 

Efficiency 

Baseline Voltage 

MSP 

Sensitivity 

Voltage MSP 

Sensitivity Voltage 

Efficiency 

[%] [%] [%] [$] [$] [%] 

TSL1 99.30 16.6% (0.11) $11,491.76 $13,404.25 99.19 

TSL2 99.36 12.3% (0.09) $12,372.38 $13,895.03 99.27 

TSLD 99.42 16.2% (0.07) $13,466.22 $15,652.68 99.35 

TSLC 99.42 16.2% (0.07) $13,466.22 $15,652.68 99.35 

TSLB 99.47 20.2% (0.07) $15,227.23 $18,296.21 99.40 

TSL3 99.42 16.2% (0.07) $13,466.22 $15,652.68 99.35 

TSL4 99.47 20.2% (0.07) $15,227.23 $18,296.21 99.40 

TSLA 99.54 9.0% (0.07) $22,348.02 $24,355.59 99.47 

TSL5 99.71 n/a n/a n/a n/a n/a 

TSL6 99.71 n/a n/a n/a n/a n/a 

Average 16.9% (0.08) 

* MSP is an abbreviation for the Manufacturer’s Selling Price. 

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