How can thermography assist in generator maintenance?

• A. It reveals hot spots indicative of winding or bearing problems, enabling early intervention.
• B. It measures oil viscosity.
• C. It maps electrical impedance.
• D. It detects mechanical alignment.

Answer: (A)

Thermography in generator maintenance uses an infrared camera to visualize surface temperatures, showing where heat is concentrating across the equipment. In a generator, hotspots usually signal problems in winding insulation or bearings. Winding areas under excessive electrical load or nearing insulation failure will heat up more than the surrounding turns, while bearings with wear or insufficient lubrication generate localized heat from friction. Detecting these hot spots early lets you target inspections, tighten connections, balance cooling, replace worn bearings, or adjust loading before a failure occurs, reducing downtime and costly repairs.

This method isn’t used to measure oil viscosity, which requires a viscometer, nor to map electrical impedance, which needs electrical test equipment. It also isn’t a direct method for checking mechanical alignment, which relies on alignment tools and procedures.