Energy conservation standards and their effective dates.

  1. Law
  2. CFR 10
  3. Energy
  4. Department of Energy
  5. Energy Conservation
  6. Energy Efficiency Program for Certain Commercial and Industrial Equipment
  7. Distribution Transformers
  8. Energy Conservation Standards
  9. Energy conservation standards and their effective dates.

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§ 431.196 Energy conservation standards and their effective dates.

(a) Low-Voltage Dry-Type Distribution Transformers.

(1) The efficiency of a low-voltage, dry-type distribution transformer manufactured on or after January 1, 2007, but before January 1, 2016, shall be no less than that required for the applicable kVA rating in the table below. Low-voltage dry-type distribution transformers with kVA ratings not appearing in the table shall have their minimum efficiency level determined by linear interpolation of the kVA and efficiency values immediately above and below that kVA rating.

Expand Table
Single-phase Three-phase
kVA % kVA %
15 97.7 15 97.0
25 98.0 30 97.5
37.5 98.2 45 97.7
50 98.3 75 98.0
75 98.5 112.5 98.2
100 98.6 150 98.3
167 98.7 225 98.5
250 98.8 300 98.6
333 98.9 500 98.7
750 98.8
1000 98.9
Note 1 to paragraph (a)(1):

All efficiency values are at 35 percent per-unit load.

(2) The efficiency of a low-voltage dry-type distribution transformer manufactured on or after January 1, 2016, shall be no less than that required for their kVA rating in the table below. Low-voltage dry-type distribution transformers with kVA ratings not appearing in the table shall have their minimum efficiency level determined by linear interpolation of the kVA and efficiency values immediately above and below that kVA rating.

Expand Table
Single-phase Three-phase
kVA Efficiency
(%) 		kVA Efficiency
(%)
15 97.70 15 97.89
25 98.00 30 98.23
37.5 98.20 45 98.40
50 98.30 75 98.60
75 98.50 112.5 98.74
100 98.60 150 98.83
167 98.70 225 98.94
250 98.80 300 99.02
333 98.90 500 99.14
750 99.23
1000 99.28
Note 2 to paragraph (a)(2):

All efficiency values are at 35 percent per-unit load.

(b) Liquid-Immersed Distribution Transformers.

(1) The efficiency of a liquid-immersed distribution transformer manufactured on or after January 1, 2010, but before January 1, 2016, shall be no less than that required for their kVA rating in the table below. Liquid-immersed distribution transformers with kVA ratings not appearing in the table shall have their minimum efficiency level determined by linear interpolation of the kVA and efficiency values immediately above and below that kVA rating.

Expand Table
Single-phase Three-phase
kVA Efficiency
(%) 		kVA Efficiency
(%)
10 98.62 15 98.36
15 98.76 30 98.62
25 98.91 45 98.76
37.5 99.01 75 98.91
50 99.08 112.5 99.01
75 99.17 150 99.08
100 99.23 225 99.17
167 99.25 300 99.23
250 99.32 500 99.25
333 99.36 750 99.32
500 99.42 1000 99.36
667 99.46 1500 99.42
833 99.49 2000 99.46
2500 99.49
Note 3 to paragraph (b)(1):

All efficiency values are at 50 percent per-unit load.

(2) The efficiency of a liquid-immersed distribution transformer manufactured on or after January 1, 2016, shall be no less than that required for their kVA rating in the table below. Liquid-immersed distribution transformers with kVA ratings not appearing in the table shall have their minimum efficiency level determined by linear interpolation of the kVA and efficiency values immediately above and below that kVA rating.

Expand Table
Single-phase Three-phase
kVA Efficiency
(%) 		kVA Efficiency
(%)
10 98.70 15 98.65
15 98.82 30 98.83
25 98.95 45 98.92
37.5 99.05 75 99.03
50 99.11 112.5 99.11
75 99.19 150 99.16
100 99.25 225 99.23
167 99.33 300 99.27
250 99.39 500 99.35
333 99.43 750 99.40
500 99.49 1000 99.43
667 99.52 1500 99.48
833 99.55 2000 99.51
2500 99.53
Note 4 to paragraph (b)(2):

All efficiency values are at 50 percent per-unit load.

(c) Medium-Voltage Dry-Type Distribution Transformers.

(1) The efficiency of a medium-voltage dry-type distribution transformer manufactured on or after January 1, 2010, but before January 1, 2016, shall be no less than that required for their kVA and BIL rating in the table below. Medium-voltage dry-type distribution transformers with kVA ratings not appearing in the table shall have their minimum efficiency level determined by linear interpolation of the kVA and efficiency values immediately above and below that kVA rating.

Expand Table
Single-phase Three-phase
kVA BIL* kVA BIL
20-45 kV 46-95 kV ≥96 kV 20-45 kV 46-95 kV ≥96 kV
Efficiency
(%) 		Efficiency
(%) 		Efficiency
(%) 		Efficiency
(%) 		Efficiency
(%) 		Efficiency
(%)
15 98.10 97.86 15 97.50 97.18
25 98.33 98.12 30 97.90 97.63
37.5 98.49 98.30 45 98.10 97.86
50 98.60 98.42 75 98.33 98.12
75 98.73 98.57 98.53 112.5 98.49 98.30
100 98.82 98.67 98.63 150 98.60 98.42
167 98.96 98.83 98.80 225 98.73 98.57 98.53
250 99.07 98.95 98.91 300 98.82 98.67 98.63
333 99.14 99.03 98.99 500 98.96 98.83 98.80
500 99.22 99.12 99.09 750 99.07 98.95 98.91
667 99.27 99.18 99.15 1000 99.14 99.03 98.99
833 99.31 99.23 99.20 1500 99.22 99.12 99.09
2000 99.27 99.18 99.15
2500 99.31 99.23 99.20

* BIL means basic impulse insulation level.

Note 5 to paragraph (c)(1):

All efficiency values are at 50 percent per-unit load.

(2) The efficiency of a medium- voltage dry-type distribution transformer manufactured on or after January 1, 2016, shall be no less than that required for their kVA and BIL rating in the table below. Medium-voltage dry-type distribution transformers with kVA ratings not appearing in the table shall have their minimum efficiency level determined by linear interpolation of the kVA and efficiency values immediately above and below that kVA rating.

Expand Table
Single-phase Three-phase
kVA BIL* kVA BIL
20-45 kV 46-95 kV ≥96 kV 20-45 kV 46-95 kV ≥96 kV
Efficiency
(%) 		Efficiency
(%) 		Efficiency
(%) 		Efficiency
(%) 		Efficiency
(%) 		Efficiency
(%)
15 98.10 97.86 15 97.50 97.18
25 98.33 98.12 30 97.90 97.63
37.5 98.49 98.30 45 98.10 97.86
50 98.60 98.42 75 98.33 98.13
75 98.73 98.57 98.53 112.5 98.52 98.36
100 98.82 98.67 98.63 150 98.65 98.51
167 98.96 98.83 98.80 225 98.82 98.69 98.57
250 99.07 98.95 98.91 300 98.93 98.81 98.69
333 99.14 99.03 98.99 500 99.09 98.99 98.89
500 99.22 99.12 99.09 750 99.21 99.12 99.02
667 99.27 99.18 99.15 1000 99.28 99.20 99.11
833 99.31 99.23 99.20 1500 99.37 99.30 99.21
2000 99.43 99.36 99.28
2500 99.47 99.41 99.33

* BIL means basic impulse insulation level.

Note 6 to paragraph (c)(2):

All efficiency values are at 50 percent per-unit load.

(d) Mining Distribution Transformers. [Reserved]

[78 FR 23433, Apr. 18, 2013, as amended at 86 FR 51252, Sept. 14, 2021]


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