Partial-discharge-inception testing on low-voltage motors

This is a review of one manufacturer's efforts toward testing National Electrical Manufacturers Association (NEMA) low-voltage motor insulation for compatibility with adjustable-speed drives (ASDs). Partial-discharge-inception-voltage (PDIV) measurements were selected as a tool to evaluate the future performance of the stator insulation system to resist deterioration by the drives. PDIV measurement is explained in terms of procedure and accuracy. Data are presented from tests made on motors from several prominent manufacturers.