Low voltage and VFD driven electric motors will often have voltage stresses between conductors. In cases where this is severe, it is detectible as discharges in the airgap of the machine. In this paper we will review one of the applications associated with turn faults stresses in stator windings of induction. The discovery was originally made in laboratory testing in 1988 but was confirmed during special testing of electric machines that operate in a vacuum by MotorDoc LLC.
Winding Stress Detection with ESA