What is the maximum interval for connecting a mid-roof run to the perimeter circuit?

The maximum interval for connecting a mid-roof run to the perimeter circuit is set at 100 feet. This distance is based on standards outlined by the National Fire Protection Association (NFPA) and Underwriters Laboratories (UL), which define optimal spacing for lightning protection systems to ensure effectiveness in safely conducting lightning strikes.

To achieve proper grounding and to minimize the risk of lightning-induced surges in electrical systems, the 100-foot interval helps maintain effective current carrying paths. By adhering to this distance, the system can ensure that lightning energy is efficiently routed to ground with minimal risk of side flashing or other hazardous scenarios.

This designed structure aims to balance both practicality and safety within lightning protection systems, ensuring that all areas of a rooftop are adequately covered without excessive intervals leading to potential vulnerabilities.