Shaft voltage and bearing currents represent critical reliability challenges for large-scale gubernators. Left unmanaged, these phenomena accelerate bearing degradation, trigger unplanned outages, and compromise machine longevity. This paper investigates the physical mechanisms of shaft voltage generation through a detailed case study of a 210 MW KWU-design turbine following a scheduled overhaul. By correlating electromagnetic, capacitive, magnetic, and electrostatic sources with field observations, this study proposes a robust framework of tiered operational thresholds. Findings indicate that voltages exceeding specific levels, when paired with leakage currents, serve as vital condition-monitoring indicators to prevent catastrophic failure
Shobhan Kumar Malana (Thu,) studied this question.