What is the function of a surge arrestor?

The correct function of a surge arrestor is to limit surge current. Surge arrestors are essential components in electrical systems that protect equipment and systems from voltage spikes, typically caused by lightning strikes, switching surges, or other transient events. When a voltage spike occurs, the surge arrestor diverts the excess energy away from sensitive equipment by providing a low-resistance path to ground. This action helps to prevent damage, maintaining the integrity of electrical systems and prolonging their lifespan.

In contrast, the other options do not accurately describe the role of a surge arrestor. Increasing voltage pertains to devices such as transformers, while regulating power supply involves devices like voltage regulators or uninterruptible power supplies. Monitoring energy usage is typically performed by energy meters, not surge arrestors. Understanding these distinctions is crucial for recognizing the specific functions of electrical components in a system.