What action occurs when a generator's overvoltage control is triggered?

When a generator's overvoltage control is triggered, it opens the shunt field circuit. This action is a protective measure designed to prevent damage to the generator and connected systems caused by excessive voltage.

In normal operation, the shunt field circuit is responsible for regulating the voltage produced by the generator. When the voltage exceeds a certain threshold, the overvoltage control intervenes by disconnecting the shunt field circuit, which effectively reduces the field excitation power. As a result, the generator's output voltage decreases, bringing it back within safe operational limits. This protective feature is essential for maintaining the integrity and reliability of the electrical system connected to the generator. By doing this, the overvoltage control helps to ensure the safe functioning of electrical equipment and prevents potential hazards associated with overvoltage situations.