🔍 Key Concepts

• Role of shaft currents in rotating electrical machinery • How insulation between bearing and housing affects current paths • Common problems caused by unintended electrical paths in generator shafts and bearings

💭 Think About

• Think about what can happen if electrical current is allowed to flow through the shaft and bearings of a generator. • Which of the listed problems is most directly related to electricity finding an unintended path to ground? • How would insulating one bearing shell from its housing change the path that any stray current could take?

✅ Before You Answer

• Identify which option is specifically related to electrical current paths rather than mechanical wear or heat alone. • Consider what problem occurs when current passes through metal-to-metal contact in bearings (pitting, fluting, damage). • Verify which effect would be reduced or stopped if the current cannot flow from shaft, through bearing, to the housing.