Insulation of small and medium size motors-IGBT inverter fed

Motors connected to an IGBT ASD may experience high voltage peak stresses which increase the possibility of failure. If an IGBT ASD is being installed as a replacement to an existing drive, the system setup must be reviewed to reduce or eliminate the peak voltage stress. The cleanliness and condition of the motor being driven must be considered and the user should be especially careful when applying fractional horsepower motors to ASDs. In the specification of new motors, the motor manufacturer should be aware of the circumstances of the system including a prediction of peak voltage potential. At this time, special insulation is recommended for motors operating on IGBT inverter-fed adjustable speed drives above 450 V