What is one of the key roles of a lightning arrestor?

A lightning arrestor plays a crucial role in protecting electrical systems from the damaging effects of lightning strikes. When lightning strikes a power line or electrical equipment, it can induce a powerful surge of current. The key function of the lightning arrestor is to "choke off follow-through current," which means it diverts the excess voltage and current away from sensitive equipment and into the ground. This helps to prevent damage to transformers, circuit breakers, and other electrical devices by ensuring that the surge does not continue to travel through the system, potentially causing catastrophic failures.

While enhancing equipment longevity might be a secondary benefit of protecting devices from surges, the primary function directly relates to managing follow-through current during an overvoltage event. Similarly, options pertaining to increasing voltage or providing an alternative energy source do not align with the primary purpose of a lightning arrestor, which focuses on surge protection rather than altering circuit parameters or generating energy.