Is it ok to connect the lightning protection system (LPS) to the main grounding system?
Yes, you must bond your Lightning Protection System (LPS) to your all other grounding systems at your facility. Failure to do so would be a major violation under every known standard and regulation we are aware of. While it seems counter-intuitive to bring lightning energy into your other grounding systems, it is more important that there are no differences in potential between the two systems. Differences in potential allow hazardous voltages to form and leads to arc-flash and other serious electrical issues.
The bottom line is that you must bond your Lightning Protection System (LPS) to your electrical grounding system.
The Engineering Experts at E&S Grounding Solutions