Prolec GE Waukesha’s Waukesha, Wisconsin, facility includes over 144,000 square feet of manufacturing space dedicated to large power transformer production, testing and shipping. With capabilities up to 1200 MVA top for autotransformers, up to 345kV, the facility was designed as state-of-the-art, utilizing equipment from some of the industry’s leading manufacturers. With this top-of-the-line equipment and optimized production flow, our well-trained and experienced employees are proud to offer large power transformers for a variety of applications.

​Large Power Transformer Manufacturing
Transformer Vapor Phase


Three-phase transformers include three-leg or five-leg geometry. Single phase transformers are designed using two-leg, three-leg or four-leg geometry. Our automatic GEORG cutting machines and customized, state-of-the-art GEORG stacking table include swing shear lines for high quality, cost-effective production of these complex power transformer cores. Advantages of this system include:

  • Laminations cut with absolute minimum burr height
  • High level of stacking accuracy
  • Careful treatment of highly sensitive surfaces
  • Step lap construction reduces no load losses and noise levels
SPX Tranformer Factory


  • Fully enclosed and environmentally-controlled coil winding room
  • Larger windings produced on state-of-the-art vertical and horizontal winding machines
  • Interleaved, shielded disc, helical, disc or layer construction (depending on voltage and impulse rating)
SPX Transformer work floor


State-of–the-art Hedrich front entry vapor phase chambers utilized for coil stabilizing and core/coil assembly drying, including iso-static pressing for coil stabilization and precise measurements, ensuring compliance to design standards. Other benefits include

  • Optimization of heat transfer, process time and residual moisture
  • Iso-static sizing leads to good elastic behavior and ‘sizing pressure’ is maintained during service to provide safety against short circuit forces


  • Humidity and dust controlled environment to minimize potential for contamination and moisture ingress, ensuring <0.5% moisture content in the finished transformer
  • Low humidity “desert” room to deter moisture ingress during final adjustments after vapor phase prior to transformer tanking
  • 500 ton crane capacity


  • Faraday Cage test lab electrically and mechanically isolated to minimize outside interference in test results and ambient partial discharge <5pc
  • State-of-the-art Haefely test equipment utilized to ensure that each transformer meets or exceeds industry standards and customer specifications
  • Capable of performing routine and special tests, including dielectric, heat run and frequency response analysis (FRA) as per industry standards
  • Capable of performing sound level testing