How does over voltage protection function in an aircraft?

Overvoltage protection in an aircraft is crucial for safeguarding the electrical system and ensuring the aircraft's safe operation. When the voltage generated by the alternator exceeds predetermined limits—commonly set at around 17 volts—an overvoltage protection relay is triggered. This relay disconnects the alternator from the electrical system, effectively preventing any excess voltage from reaching the aircraft's critical components, which could otherwise lead to damage.

This form of protection is essential because an overvoltage condition can cause various problems, such as overheating wires, damaging avionics, or affecting the performance of electrical components. By automatically taking the alternator offline, the system ensures the safety and reliability of the aircraft’s electrical system.

Other options describe potential safety measures but do not specifically address how overvoltage protection operates in this context. For instance, while a fuse may blow in the event of a short circuit or overload, it is not the typical mechanism for controlling overvoltage. Disconnecting the battery could lead to other operational issues, and warning lights serve primarily as alerts rather than preventative measures against overvoltage conditions.