This webinar recording reviews the failures associated with 3-phase motors on Variable Frequency Drives (VFDs) and how to rewind to limit future failures.

This paper describes partial discharge, explains how to detect it, and offers repair solutions.

Concerns about partial discharge (PD) used to be limited to repairers and users of machines rated over 7 kV. PD is a common consideration for machines rated 11 kV and higher. This article will describe PD, explain how to detect it, and offer repair solutions. Discussion includes:

• What is partial discharge?
• Air as an insulator
• Can we fix it?
• Detecting partial discharge
• Monitoring partial discharge activity
• Partial discharge in random windings

When rewinding a motor, the service center is restricted by the original design. Sometimes, we encounter a motor design we wish had never been developed. The random-wound, 2300-volt motor design falls into that category. The great challenge to the service center is in successfully rewinding this design while maintaining profit.