Which are typical indicators that cooling system maintenance is due?

• A. Increased airflow and cooler windings.
• B. Decreased airflow, coolant leaks, clogged radiators, and rising winding temperatures.
• C. No changes in windings' temperature.
• D. Coolant color change to bright green.

Answer: (B)

Cooling systems are designed to remove heat from the generator windings, so maintenance is typically due when cooling performance drops. The clear signs are decreased airflow through the cooling path, coolant leaks that reduce the amount of circulating coolant, clogged radiators that hinder heat transfer, and windings temperatures that are rising toward or beyond acceptable limits. When you see these indicators, it means the system isn’t removing heat effectively and should be inspected—checking fans and ducts, locating and repairing leaks, cleaning or replacing clogged radiators, and verifying coolant levels and quality. Conversely, increased airflow with cooler windings, or no change in winding temperature, would suggest the cooling system is currently functioning well. A coolant changing color to bright green is not a reliable indicator by itself of maintenance need.