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MVA transformers, 1 to 100 MVA
An MVA transformer is a power or substation transformer rated in megavolt amperes, 1 MVA being 1,000 kVA. Below is every common size from 1 to 100 MVA with its full load current at six voltages, what a stacked rating such as 12/16/20 MVA means, the published price benchmarks and today's lead times. We source new, surplus and used units in this range and quote them delivered.
Standard MVA sizes with full load amps
Full load current for a three phase transformer is MVA x 1,000,000 divided by (1.732 x line voltage). Every figure below is computed that way, so read the column for the winding you are sizing. Units up to about 10 MVA are often built as large pad mounted or unit substation transformers, while the larger sizes are substation power transformers with a 34.5, 69 or 138 kV primary.
| MVA | kVA | Amps at 4.16 kV | Amps at 12.47 kV | Amps at 13.8 kV | Amps at 34.5 kV | Amps at 69 kV | Amps at 138 kV |
|---|---|---|---|---|---|---|---|
| 1 | 1,000 | 139 | 46 | 42 | 17 | 8.4 | 4.2 |
| 1.5 | 1,500 | 208 | 69 | 63 | 25 | 13 | 6.3 |
| 2 | 2,000 | 278 | 93 | 84 | 33 | 17 | 8.4 |
| 2.5 | 2,500 | 347 | 116 | 105 | 42 | 21 | 10 |
| 3 | 3,000 | 416 | 139 | 126 | 50 | 25 | 13 |
| 3.75 | 3,750 | 520 | 174 | 157 | 63 | 31 | 16 |
| 5 | 5,000 | 694 | 231 | 209 | 84 | 42 | 21 |
| 7.5 | 7,500 | 1,041 | 347 | 314 | 126 | 63 | 31 |
| 10 | 10,000 | 1,388 | 463 | 418 | 167 | 84 | 42 |
| 12 | 12,000 | 1,665 | 556 | 502 | 201 | 100 | 50 |
| 15 | 15,000 | 2,082 | 694 | 628 | 251 | 126 | 63 |
| 20 | 20,000 | 2,776 | 926 | 837 | 335 | 167 | 84 |
| 25 | 25,000 | 3,470 | 1,157 | 1,046 | 418 | 209 | 105 |
| 30 | 30,000 | 4,164 | 1,389 | 1,255 | 502 | 251 | 126 |
| 40 | 40,000 | 5,551 | 1,852 | 1,673 | 669 | 335 | 167 |
| 50 | 50,000 | 6,939 | 2,315 | 2,092 | 837 | 418 | 209 |
| 60 | 60,000 | 8,327 | 2,778 | 2,510 | 1,004 | 502 | 251 |
| 75 | 75,000 | 10,409 | 3,472 | 3,138 | 1,255 | 628 | 314 |
| 100 | 100,000 | 13,879 | 4,630 | 4,184 | 1,673 | 837 | 418 |
Computed values, rounded to the nearest amp. Use the kVA to amps calculator for any other voltage.
Stacked ratings, 12/16/20 MVA and ONAN, ONAF
Many substation transformers carry two or three ratings on one nameplate. The first number is the self cooled rating, oil natural and air natural, written ONAN (formerly OA). Each higher number is the rating with a stage of cooling fans running, written ONAF (formerly FA). A 12/16/20 MVA unit carries 12 MVA with no fans, 16 MVA with the first set of fans and 20 MVA with both sets.
Two things follow. The percent impedance on the nameplate is normally stated on the self cooled base, so check the base before you run fault studies. And a 12/16/20 unit is not a 20 MVA unit in a hot climate if a fan stage is out. Size the load against the stage you can rely on.
| Rating | Cooling | Amps at 13.8 kV | Amps at 69 kV | Amps at 115 kV |
|---|---|---|---|---|
| 12 MVA | Self cooled, ONAN | 502 | 100 | 60 |
| 16 MVA | First fan stage, ONAF | 669 | 134 | 80 |
| 20 MVA | Second fan stage, ONAF | 837 | 167 | 100 |
Example of a 12/16/20 MVA nameplate. Amps computed from MVA and voltage.
MVA transformer prices
Power transformer prices are quoted per unit, not from a list, and they move with steel, copper and the order book. These are published benchmarks, not our prices. A quote from us is a delivered price for a specific unit.
| Benchmark | Figure | Published by |
|---|---|---|
| New large power transformer procurement price | $15,000 to $21,000 per MVA | NextMSC, citing USITC data via NLR |
| 100 MVA unit at that benchmark | $1.5 million to $2.1 million | NextMSC calculation |
| Highly customized 100 MVA unit | Up to about $4 million | NextMSC, citing NLR |
| Upper single unit benchmark | About $10 million | NextMSC, citing USITC via NLR |
| Average declared value of US imports above 100 MVA, 2025 | About $1.22 million a unit | NextMSC, from import data for liquid dielectric transformers above 100,000 kVA |
Benchmarks are for large power transformers. Smaller MVA units are quoted per job and are not a straight multiple of these figures.
Lead times by class
Lead time, not price, is what decides most projects in this range. Wood Mackenzie's survey for the second quarter of 2025 put the average power transformer lead time at 128 weeks, about two and a half years, after a 10 week improvement in that quarter. Generator step up units averaged 143 weeks. Some specialized orders run to four years.
Wood Mackenzie also expected a 30 percent supply shortfall for power transformers in the US in 2025, with imports making up an estimated 80 percent of US power transformer supply. That is why surplus, used and reconditioned units and cancelled order slots are worth asking about in this size range.
| Equipment | Typical lead time | Published by |
|---|---|---|
| Power transformers, average | 128 weeks (Q2 2025) | Wood Mackenzie, via Industrial Sage and Giga Energy |
| Generator step up transformers, average | 143 to 144 weeks (Q2 2025) | Wood Mackenzie, via Industrial Sage and NextMSC |
| Large power transformers, current | 30 to 36 months | NextMSC, citing NLR |
| Large power transformers, before the shortage | 12 to 18 months | NextMSC, citing NLR |
| Extra high voltage transformers | Up to 60 months | NextMSC, citing DOE and NLR |
| High voltage bushings | Up to about 130 weeks | NextMSC |
| On load tap changers | About 80 to 90 weeks | NextMSC |
| Switchgear, average | 44 weeks (Q2 2025) | Wood Mackenzie |
| Three phase pad mounts for data centers | 40 weeks and more, per EPC quotes | Giga Energy |
What moves the price and the date
Wood Mackenzie reported electrical steel prices rising more than 20 percent in a few months of 2025, which moves contracts that carry a price adjustment formula, and named winding grade copper as a production bottleneck. New tariffs, including a 50 percent tariff on copper from August 2025, push up both imported and domestically built units. Expect a quote in this range to carry a validity period and a metals adjustment clause.
New US capacity is coming, but late. Hitachi Energy broke ground on a $457 million expansion in South Boston, Virginia in June 2026 and plans a $528 million plant in Mississippi with production in 2029, according to NextMSC.
Weight and footprint
Weight and footprint vary too much by voltage class, impedance, cooling and the maker to publish one range per size, and we did not find a public source we trust that does. Ask for the outline drawing with any quote. It gives the shipping weight, the oil volume, the untanking weight and the pad dimensions you need for rigging, transport permits and the foundation.
What to send for a quote
- MVA rating, and the stacked ratings if you need fan stages, for example 12/16/20 MVA ONAN/ONAF/ONAF
- Primary and secondary voltage, for example 69 kV delta to 13.8Y/7.97 kV, and the BIL if your utility specifies it
- Percent impedance, especially if you are matching or paralleling an existing unit
- Tap changer, de energized taps or an on load tap changer
- New, surplus, used or reconditioned, and the factory tests you need on paper
- Site ZIP code and the date you need it energized
Common questions
What does MVA mean on a transformer
MVA is megavolt amperes, the apparent power the transformer can deliver. 1 MVA is 1,000 kVA. A transformer is rated in MVA or kVA rather than MW because its heating depends on current and voltage, not on the power factor of the load.
How many amps is a 1 MVA transformer
At 480 V three phase, 1 MVA is about 1,203 A. At 12.47 kV it is about 46 A, and at 13.8 kV about 42 A. The formula is MVA x 1,000,000 divided by (1.732 x volts).
What are standard MVA transformer sizes
Common sizes include 1, 1.5, 2, 2.5, 3, 3.75, 5, 7.5, 10, 12, 15, 20, 25, 30, 40, 50, 60, 75 and 100 MVA, and larger units often carry stacked ratings such as 12/16/20 MVA for their fan stages.
How much does a 100 MVA transformer cost
A published benchmark of $15,000 to $21,000 per MVA gives $1.5 million to $2.1 million for a 100 MVA unit, and highly customized units can reach about $4 million, according to NextMSC. Freight, installation, testing and commissioning are extra.
What is the lead time for a power transformer
Wood Mackenzie's Q2 2025 survey put the average at 128 weeks, and generator step up units at about 143 weeks. Large units are commonly quoted at 30 to 36 months. Surplus and used units can ship much sooner.
What does 12/16/20 MVA mean
It is a stacked rating. The transformer carries 12 MVA self cooled (ONAN), 16 MVA with the first stage of fans and 20 MVA with the second stage (ONAF).
Related pages
Sources
- NextMSC, US transformer and switchgear prices and lead times, October 2026 research update
- Wood Mackenzie, Mind the gap, tackling supply chain challenges in the electric T&D sector
- Industrial Sage, Power transformer lead times reach 128 weeks
- Giga Energy, Lead time delays for data centers
- pv magazine, US transformer supply may fall sharply in 2025, says Wood Mackenzie
- MB Drive Services, How to interpret dual rating transformers
- CR4 GlobalSpec forum, ONAF cooling and stacked ratings
Market figures are public asking prices and published industry figures, dated where the source gives a date. They are not our prices. A quote from us is a delivered price for a specific unit.