What is a condition that leads to a turbine overspeed trip?

The condition that leads to a turbine overspeed trip is mechanical overspeed, which occurs when the turbine rotates faster than its designed operational limits. Specifically, the range of 6098 to 6222 rpm indicates an operational threshold beyond which the turbine's integrity can be compromised. When the turbine exceeds this mechanical overspeed threshold, various mechanical stresses may rise significantly, potentially resulting in catastrophic failure of the turbine components. To prevent such damage, turbine systems are equipped with protective measures to trip the turbine automatically when these dangerous speeds are detected.

In contrast, electrical overspeed is not a common condition that leads to a turbine trip as mechanical factors are usually more critical in the operational limits of turbine design. While other factors like heat exchanger failure or low pressure in the condenser can cause operational issues, they do not directly cause an overspeed condition that necessitates a trip for safety protocol; they may lead to a separate set of performance or efficiency problems.