What is the primary function of a surge arrestor?

The primary function of a surge arrestor is to provide a path for a surge to discharge to ground. Surge arrestors are designed to protect electrical equipment from transient voltage surges, such as those caused by lightning strikes or power surges. When a surge occurs, the surge arrestor detects the excessive voltage and enables the electrical energy associated with the surge to flow safely to the ground. This action prevents the excess voltage from damaging sensitive electrical components and systems, thereby maintaining the integrity and reliability of the equipment.

Other options do not align with the function of a surge arrestor. Storing electrical energy pertains to devices like capacitors or batteries, which have different operational purposes. Increasing voltage levels is typically the role of transformers or voltage boosters, which serve to elevate voltage for transmission, not to mitigate surges. Enhancing signal transmission relates more to signal boosters or repeaters instead of surge protection, which focuses on the safe diversion of harmful surges. Thus, the correct choice accurately reflects the protective mechanism of surge arrestors in electrical systems.