What is the relationship between a lightning rod and lightning arrestor?

The relationship between a lightning rod and a lightning arrestor is that the arrestor enhances the protection offered by the rod, making it a critical component in an overall lightning protection system.

A lightning rod is designed to safely direct a lightning strike into the ground, preventing damage to a structure. It offers a physical path for the electrical energy to dissipate harmlessly, thereby protecting the building and its occupants. On the other hand, a lightning arrestor (or surge arrestor) is designed to protect electrical equipment from the high voltage that can be induced by a lightning strike, or from surges in electrical systems.

When used together, the lightning rod directs the strike away from the structure, while the lightning arrestor protects the connected electrical systems from surges, ensuring that overall protection is comprehensive. This synergistic relationship is what makes the arrestor an enhancement to the protection provided by the rod, addressing both physical damage to the building itself and potential damage to sensitive electronic equipment adjoining the structure.