GE Vernova (Prolec GE) Generator step-up transformers (to 1,000 MVA / 765 kV)
Prolec GE generator step-up transformers to 1,000 MVA and 765 kV, now fully inside GE Vernova
GE Vernova (Prolec GE) Generator step-up transformers (to 1,000 MVA / 765 kV) is one of 32 data center transformers tracked in the SecondWatt catalogue, each with specifications, lead times and indicative secondary-market pricing.
GE Prolec GSU dossier: step-up transformers to 1,000 MVA and 765 kV, 1,675 kV BIL, GE Vernova acquisition, used-market channels, inspection checklist.
Why it matters
GSU demand grew 274% from 2019 to 2025, the steepest curve in the transformer complex, and every behind-the-meter generation project SecondWatt tracks needs one. Prolec GE is the largest transformer producer in the Americas, and its absorption into GE Vernova concentrates GSU capacity with the same OEM selling the gas turbines those projects deploy.
Who buys it
Power producers repowering gas and hydro plants, utilities holding spares against 144-week GSU lead times, and behind-the-meter generation projects at data center campuses buy this class. Waukesha-badged legacy units carry a dedicated used category, so fleet managers also source them for like-for-like replacement in existing yards.
Role in the data center
Step-up transformer for on-site generation at campuses, taking 13.8-18 kV turbine output to transmission voltage; the pacing item on behind-the-meter power schedules.
Key specifications
| LV winding range | 13.2-25 kV delta |
|---|---|
| HV winding range | 69-765 kV wye |
| NA capacity ceiling | 600 1-phase / 900 3-phase MVA |
| Brazil capacity ceiling | 1,000 MVA 3-phase / 800 kV |
| NA BIL ceiling | 1,675 (550 kV class) kV |
| Cooling classes | ONAN / ONAF / ODAF |
| Installed base | 300,000+ MVA / 35 countries |
| GE Vernova buyout | 5.275B USD, completed 2026-02-02 |
| Goldsboro NC expansion | 140M USD, 330 jobs |
| Used GSU category depth | 107 listings |
Technical summary
LV windings: 13.2-25 kV delta HV windings: 69-765 kV wye Capacity, North America: to 600 MVA 1-phase / 900 MVA 3-phase Capacity, Brazil (Canoas): to 1,000 MVA 3-phase, 800 kV NA voltage/BIL ceiling: 550 kV class, 1,675 kV BIL Cooling: ONAN / ONAF / ODAF Standards: ANSI, IEEE, CSA, IEC; 50/60 Hz Noise: low-noise designs to NEMA minus 25 dBA Installed base: 300,000+ MVA in 35 countries Related lines: station service and unit auxiliary transformers below 50 MVA
Pricing and availability
Trend: up Lead time, new: 100-150+ weeks (GSU class); 144 weeks Q2 2025 average. Lead time, used or refurbished: 2-12 weeks. Warranty, used: 3-year typical from major US rebuilders.
Lifecycle and maintenance
Liquid-filled transformers routinely serve 30-40 years with annual oil screening, DGA on a 1-2 year cadence (or continuous online monitoring on critical units), and gasket or bushing service as tests dictate. Major US rebuilders remanufacture units to like-new condition with warranties up to 3 years (T&R Electric, Sunbelt Solomon), and reconditioned stock ships in days against 65-210 week new-build queues. Remaining paper life, estimated by furan testing, governs end-of-life valuation.
Common failure points
- Windings — Dielectric failure; windings dominate major-failure statistics in CIGRE TB 642
- Bushings — Failure share rises with voltage class; OIP bushing faults can rupture tanks
- OLTC — Contact and mechanism wear; prominent failure source on substation units
- Winding deformation — Through-fault or transport damage shifting SFRA signature
- Cooling system — Pump, fan, and radiator degradation derating the unit
- Moisture and paper aging — Furans in oil and reduced degree of polymerization
Inspection checklist
DGA — dissolved gas analysis per IEEE C57.104; combustible-gas trend rise between 2 samples triggers investigation Oil quality — dielectric breakdown, moisture, acidity, and furan tests; degree of polymerization below 200 marks end of paper life Insulation resistance — megger HV/LV/ground; polarization index of 2.0 or higher passes Power factor — insulation power factor testing; values above 1.0% on oil-filled windings warrant investigation Turns ratio — TTR on all taps; deviation beyond 0.5% from nameplate fails Winding resistance — three-phase balance within 2% between phases Bushings — capacitance and power factor test; bushing failure share rises with voltage class per CIGRE TB 642 OLTC — inspect on-load tap changer diverter and selector; OLTCs are a leading failure component in CIGRE TB 642 fleet surveys SFRA — sweep frequency response analysis per IEEE C57.149 against baseline to detect winding deformation after transport Transport records — review impact-recorder data per IEEE C57.150 for any relocated unit of 10 MVA and above Core ground — verify a single intentional core ground; inadvertent grounds show as gassing in DGA Cooling — inspect radiators, pumps, and fans; verify stage ratings (ONAN/ONAF) against nameplate Tank and conservator — corrosion survey, gasket inspection, and pressure relief device function Nameplate verification — confirm MVA stages, impedance, BIL, and 55/65 C rise data against the factory test report Records — complete factory test report, DGA history, through-fault history, and loading records from service
Procurement channels
New units quote through GE Vernova/Prolec GE. Used channel: Surplus Record GSU category (107 listings, mostly price-on-request), Transformer Exchange (used GE Prolec 115 kV unit in stock), MARS Transformers (new-surplus 230 kV GSU), and the Waukesha-brand category for legacy units.