What is the main reason for bonding metal structures to the grounding system?

The primary reason for bonding metal structures to the grounding system is to provide protection against electrical surges. When metal structures are properly bonded to the grounding system, any unexpected electrical current or surge, such as those caused by lightning strikes or equipment faults, can be safely redirected into the ground. This helps mitigate the risks of electrical shock to individuals and minimizes damage to equipment by ensuring that excessive voltage does not detrimentally affect the building's electrical system or its components. Proper bonding is crucial for enhancing safety measures, ensuring that any stray currents have a safe pathway, which is fundamental in both residential and commercial installations.