Vacuum Pressure Impregnation

Vacuum Pressure Impregnation

Vacuum Pressure Impregnation (VPI) is a process in which a wound resin-poor winding is completely submerged in a resin. Through a combination of dry and wet vacuum and pressure cycles, the resin is absorbed into the semi-porous insulation to result in a completed winding that is theoretically void free. The VPI process is also used in low voltage machines for winding integrity and heat transfer improvement. M&C uses the VPI process throughout its product and service range, from LV to HV.

M&C use three VPI insulation systems ensuring the correct insulation system for the specific motor and application:

  • Thixotropic for low-voltage windings
  • Dobeckan for DC windings
  • EpoVolt for high & medium voltage AC motors & generator windings

Advantages of using the VPI system are as follows:

  • Protection against excessive movement of conductors
  • Improved heat transfer from conductor to core and thermal endurance
  • Seals insulation against destructive environments
  • Provides a composite dielectric structure
  • Excellent electrical properties
  • Homogeneous void-free insulation system
  • Improved thermal conductivity
  • Good bond strength

Cost effective and faster processing time than the resin-rich insulation system