What is the role of semiconductor blocks within arresters?

The role of semiconductor blocks within arresters primarily involves allowing controlled current passage to ground. In surge arresters, semiconductor materials are utilized to manage excess voltage and divert harmful surge currents safely to the ground. When voltage levels exceed a certain threshold, these semiconductor blocks activate, providing a pathway for the surge current while protecting downstream equipment from damage. This mechanism is crucial for ensuring the reliability and longevity of electrical systems, as it helps to mitigate the effects of transients caused by lightning strikes, switching operations, or faults in the power lines.

The other options do not accurately describe the function of semiconductor blocks within arresters. They do not serve to increase voltage, function specifically as resistors, or store electrical energy in the way that capacitors do. Instead, their primary purpose aligns closely with the concept of managing current flow, ensuring that excess energy is safely diverted away.