Maddox Transformer

US manufacturer and remanufacturer supplying padmount, substation, polemount and dry-type transformers. Headquartered in Battle Ground, Washington, with transformer production in South Carolina.

DistributionUS plantData center

Verified

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Facts

Source per value
Segment Power when the maker publishes power, GSU, HVDC, autotransformer or reactor products or a rating above 20 MVA; Distribution when it publishes distribution, pad-mount, pole-mount, network or dry-type products; both when it publishes each. Derived from Transformer types and Largest rating.
Distribution 1
Transformer types Product types the maker lists, separated by semicolons: power, GSU, autotransformer, HVDC, shunt reactor, substation, distribution, pad-mount, pole-mount, network, dry-type (cast resin, VPI), mobile, rectifier/industrial, renewable and data center lines.
distribution; pad-mount; pole-mount; substation; dry-type 1
Largest rating MVA Largest verified published rating in the cited product or regional scope, in MVA. Product range identifies base, forced-cooling, phase-shifter throughput or group-history claims; these rating bases are not interchangeable. Planned future ranges are described separately.
Not published
Smallest rating kVA Smallest published rating, in kVA. Shows how far down the distribution range a maker goes.
Not published
Product range The kVA/MVA range as the maker states it, by product line.
Not published
Highest voltage kV Highest voltage class the maker publishes or has delivered, in kV (AC system voltage; HVDC noted under Voltage classes).
Not published
Voltage classes Voltage classes and BIL as the source states them, by product or plant.
Not published
Plants Transformer manufacturing locations, city and country. Planned plants carry their target date. Location lists identify verified sites and may not cover every factory in a global group.
Greer, South Carolina, United States (three-phase padmount production); Woodruff, South Carolina, United States (additional production site in development, 2026) 1
Plant countries Countries with verified operating transformer manufacturing in the cited scope; not necessarily the complete global footprint. Component and service-only sites do not establish new-unit manufacturing.
United States 1
US plant Yes when an operating US transformer plant is verified; No when the source shows the maker's plants and none is in the US. Empty means not verified.
Yes 1
EU plant Yes when an operating transformer plant in an EU-27 country is verified (the UK, Norway, Switzerland and Turkey do not count). Empty means not verified.
Not published
Capacity expansion Announced transformer capacity expansions: amount in the original currency, place, announcement date, target date and output change. US and EU projects first.
Not published
Largest US/EU expansion $M Largest single announced US or EU transformer capacity investment, in US$ millions, where the source states a dollar amount. Euro amounts stay in Capacity expansion unconverted.
Not published
Expansion region Where the announced capacity expansions are: US, EU, both, or only elsewhere (Other).
Not published
Certifications and standards Quality certifications, listings and design standards the source names (ISO 9001, IEEE C57, IEC 60076, EU Ecodesign Tier 2, utility approvals).
ANSI, NEMA, DOE and IEEE standards as applicable 1
Data center offer Yes when the maker markets transformers for data centers or has disclosed a data center transformer order. Empty means not found.
Yes 2
Data center product or order The named data center line, or the disclosed order with value and date.
Padmount, substation, dry-type and polemount transformers supplied to data center and renewable energy projects 2
Parent or owner Parent company or owner where the source states one.
Not published
HQ country Country of the maker's headquarters.
United States 1
HQ region Region of the maker's headquarters.
North America 1
Legacy brands and names Sourced former names and acquired transformer businesses, retained on the current maker row to avoid duplicate supplier counts.
Not published

Sources

  1. Maddox: products, manufacturing history and headquarters accessed 2026-11-11
  2. Maddox: American-made transformers and data center projects accessed 2026-11-11

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