Magnetic Specialties ReactorAir Core  • Iron Core • DC • Single Frequency • Multi-frequency

Single Phase • Three Phase

Windings: copper and aluminum

Voltage class: up to 25kV

BIL Ratings: Up to 125 kV

Cooling: Self, forced and water



  • UL Recognized insulation system (System voltage less than 600V); 130, 180, and 220°C systems are available.
  • CE marking with declaration of conformity (ROHS and Low Voltage Directive).
  • Private labeling with customer supplied nameplate artwork (Units that are private labeled cannot carry our UL label).
  • Open core and coil or installed into one of MSI’s in-stock NEMA 1 or 3R enclosures.  Custom enclosure designs and finishes are available.
  • MSI’s engineering team provides detailed 2D drawings or 3D Solidworks models.
  • For grounded core reactors, normally closed or normally open thermal switches can be installed to protect the transformer coils.  MSI also offers thermocouples and platinum RTDs for advanced winding temperature monitoring.


MSI reactors are fully tested before shipping, both electrically and mechanically.  When requested, MSI’s testing department can provide detailed reports.

Standard electrical tests include:

  • Inductance
  • Dielectric Hi-Pot withstand test. Test voltages up to 50 kV AC, 5 kV DC
  • Audible evaluation

Optional electrical tests include:

  • Temperature rise by resistance
  • Winding resistance
  • Insulation resistance
  • Losses