Transformer manufacturers with US plants
21 makers in this table run a verified US transformer plant, and 11 of them build power transformers. 7 have a verified overseas headquarters, including Hitachi Energy (South Boston, Virginia)↗, Hyosung (Memphis)↗ and HD Hyundai (Montgomery, Alabama)↗. Pennsylvania Transformer Technology builds to 765 kV in Canonsburg↗.
| Hyosung Heavy Industries (Hyosung HICO) | Power | 2,2502 | 7651 | 1574 | — | South Korea | 2026-11-11 |
|---|---|---|---|---|---|---|---|
| HD Hyundai Electric | Power and distribution | 1,5001 | 8001 | 2004 | — | South Korea | 2026-11-11 |
| Virginia Transformer | Power and distribution | 1,4001 | 5251 | 403 | Yes | United States | 2026-11-11 |
| Prolec GE (GE Vernova) | Power and distribution | 1,2001 | 8001 | 1404 | Yes | Mexico | 2026-11-11 |
| SGB-SMIT Group | Power and distribution | 1,2001 | 7651 | — | Yes | Germany | 2026-11-11 |
| Pennsylvania Transformer Technology | Power and distribution | 7501 | 7651 | 102.52 | Yes | United States | 2026-11-11 |
| JST Power Equipment | Power and distribution | 6004 | 5004 | — | Yes | United States | 2026-11-11 |
| WEG | Power and distribution | 4001 | 5001 | 772 | Yes | Brazil | 2026-11-11 |
| Howard Industries | Power and distribution | 3005 | 3455 | 236.952 | Yes | United States | 2026-11-11 |
| Delta Star | Power | 2002 | 3452 | — | Yes | United States | 2026-11-11 |
| Eaton | Distribution | 124 | 464 | 3402 | Yes | Ireland | 2026-11-11 |
| MGM Transformers | Distribution | 102 | — | — | Yes | United States | 2026-11-11 |
| Giga Energy | Distribution | 51 | 34.51 | — | Yes | United States | 2026-11-11 |
| Olsun Electrics | Distribution | 52 | 34.51 | — | — | — | 2026-11-11 |
| ELSCO Transformers | Distribution | 2.51 | 34.51 | — | — | — | 2026-11-11 |
| Central Moloney | Distribution | — | — | 501 | — | United States | 2026-11-11 |
| Eaglerise | Distribution | — | — | — | — | — | 2026-11-11 |
| ERMCO | Distribution | — | — | — | — | United States | 2026-11-11 |
| Federal Pacific | Distribution | — | — | — | Yes | United States | 2026-11-11 |
| Hitachi Energy | Power and distribution | — | 8001 | 5283 | Yes | Switzerland | 2026-11-11 |
| Maddox Transformer | Distribution | — | — | — | Yes | United States | 2026-11-11 |
Why the plant location matters
How we sourceFreight and testing
A large power transformer built in the US skips ocean freight and import duties, and the factory is a drive away for witness testing. Distribution units move in volume, so a nearby plant shortens every reorder.
Capacity is still arriving
Several of these plants are being expanded or built now: Eaton’s Jonesville, South Carolina plant starts production in 2027↗, and Virginia Transformer plans first output in Colbert County, Alabama in January 2028↗. The full list with amounts and dates is on transformer capacity expansions.
A US plant here means an operating transformer factory confirmed by the maker or a state release. Planned plants show under Plants with their target date.