What does a surge arrester do?

A surge arrester is a crucial component used to protect electrical equipment from voltage spikes caused by lightning strikes or other surges in the electrical system. Its primary function is to limit surge voltages and prevent excessive current flow that can lead to damage. By diverting the surge energy away from sensitive equipment, it helps to maintain the integrity of the system and prolongs the lifespan of electrical components.

The other options would not correctly describe the purpose of a surge arrester. For instance, while increasing current capacity refers to components that can handle or facilitate more electrical flow, it is not the role of a surge arrester. Similarly, reducing wiring resistance and improving overall system efficiency pertain to different aspects of electrical systems, such as ensuring optimal conductivity and energy use, rather than protecting against voltage surges. Therefore, the role of a surge arrester is specifically and effectively aligned with limiting surge voltages and preventing harmful current flow.