Note: single-phase 50kVA pad -mounted transformer from Yr 2010.

y = 60x3- 448.5x2 + 1361.5x + 166

R2 = 1

$0 

$500 

$1,000 

$1,500 

$2,000 

$2,500 

25 50 75

kilovolt-ampere

Transformer Initial Cost

I.C. Poly. (I.C.)

Transformer No-load and Load Losses

No-load Load Linear (No-load) Power (Load)

y = 311.24x0.757

R2 = 0.9989

0

100

200

300

400

500

600

700

800

900

1000

25 50 75

watts

kilovolt-ampere

Transformer No-load and Load Losses

No-load Load Linear (No-load) Power (Load)

1000

1200

Transformer Total Losses

Total Power (Total)
y = 371.79x0.7538

R2 = 0.9995

0

200

400

600

800

1000

25 50 75

watts

kilovolt-ampere
kVA I.C. calc_est X^3 X^2 X

25 $1,139 $1,139 1 1 1

50 $1,575 $1,575 8 4 2

75 $1,834 $1,834 27 9 3

100 $2,276 $2,276 64 16 4

Note: Price scaled using a third order polynomial.

kVA No-load calc_est Load calc_est

Losses in watts

+ 1361.5x + 166

100

Power (Load) kVA No-load calc_est Load calc_est

25 61 61.9 309 311.2

50 100 98.3 530 526.0

75 134 134.7 727 715.0

100 171 171.1 874 888.9

Note: No-load scaled using a linear equation.

Load loss determined using a power scale.

DOE

kVA Total calc_est calc_est

25 370 371.9 375

50 630 627.1 base

75 861 851.3 854

100 1045 1057.4 1060

Losses in watts

y = 36.4x + 25.5

R2 = 0.9994

100

Power (Load)
Note:

Scaled total losses (TL) from a 50 kVA1-ph pad-mount (base)

to a 25, 75 and 100 kVA rating (S) within a 125 kV BIL design line

using the DOE 0.75 Scaling Rule:

TL1 = TL0 x (S1 / S0)^0.75

0.7538

R2 = 0.9995

100
Note: single-phase 25 kVA pole type transformer from Yr 2010.

y = 18.5x3- 40.083x2 + 67.56x + 504.71

R2 = 0.9992

$0 

$1,000 

$2,000 

$3,000 

$4,000 

$5,000 

$6,000 

10 15 25 50 100 167

kilovolt-ampere

Transformer Initial Cost

I.C. Poly. (I.C.)

2000

Transformer No-load and Load Losses

No-load Load Poly. (No-load) Poly. (Load)

y = -1.1023x4 + 16.886x3- 74.958x

R2 = 0.9998

y = -1.2538x4 + 23.144x3- 89.958x2 + 189.86x + 12.429

R2 = 0.9987

0

200

400

600

800

1000

1200

1400

1600

1800

2000

10 15 25 50 100 167

watts

kilovolt-ampere

No-load Load Poly. (No-load) Poly. (Load)

Transformer Total Losses
y = -2.3561x4 + 40.03x3

- 164.92x2 + 327.34x - 32.286

R2 = 0.9992

0

500

1000

1500

2000

2500

10 15 25 50 100 167

watts

kilovolt-ampere

Transformer Total Losses

Total Poly. (Total)
kVA I.C. calc_est X^3 X^2 X

10 $532 $551 1 1 1

15 $683 $627 8 4 2

25 $815 $846 27 9 3

50 $1,261 $1,318 64 16 4

100 $2,235 $2,153 125 25 5

167 $3,428 $3,463 216 36 6

250 $5,363 $5,359 343 49 7

Note: Price scaled using a third order polynomial.

kVA No-load calc_est Load calc_est X^4

Losses in watts

167 250

Poly. (Load)

kVA No-load calc_est Load calc_est X^4

10 34 34 137 134.2 1

15 46 48 189 197.4 16

25 63 60 296 295.7 81

50 102 104 520 492.8 256

100 191 191 781 822.2 625

167 301 300 1312 1287.3 1296

250 390 390 1856 1861.5 2401

Note: No-load and load loss scaled using a fourth order polynomial.

DOE

kVA Total calc_est calc_est

10 171 168 181

15 235 245 245

25 359 355 base

50 622 597 604

Losses in watts

74.958x2 + 137.48x - 44.714

R2 = 0.9998

167 250

Poly. (Load)
100 972 1013 1015

167 1613 1588 1492

250 2246 2251 2019

Note:

Scaled total losses (TL) from a 25 kVA1-ph pole type (base)

to a 10, 15, 50, 100, 167 and 250 kVA rating (S) within a

125 kV BIL design line using the DOE 0.75 Scaling Rule:

TL1 = TL0 x (S1 / S0)^0.75

167 250
X^3 X^2

X

111

842

2793

64 164

125 255

216 366

343 497