Incorrect Useage of Fire Alarm System SLC Surge Suppressor

Once you complete the installation of the alarm system, there is nothing stopping an engineer from designing a lightning protection system outside of the alarm system's envelope. A drawback would be the cost.

If the man stroking the check balked at the idea, maybe you could come up with some mean-time-between-failure data to support your design.

While you asked some very good questions, I'm not sure I'll be able to address all of them. But I am responding because we are looking at some similar issues to protect our data center. A recent electrical storm set off all of the fire suppression system that was supposed to protect our systems. Instead, the explosion like pressure wave did more damage than a fire would have. But that is not what you are asking about. Incidentally, a couple of weeks later the upgraded fire control system was damaged by yet another storm. Because of this, we became very motivated about checking out our ground system and protection from lighting. It seems that they go hand in hand.

NEC does not really consider lighting to be part of their responsibility. But a good ground system will give the lighting a place to go instead of your other equipment. And I don't really know what you mean by SLC/comm. circuits unless you mean shielded line communication circuits which are addressed. But if you are going to deal with surge protection, you have to specify what kind of surge you are concerned about. For example, a lighting strike usually causes a lot of common mode noise or surge. But a poor connection in one part of a circuit may be responsible for a single sided problem. Again you have to specify so the language doesn't lead you to believe that you have resolved the issue.

In our case, I believe the ground grid leaves a lot to be desired. Careful measurements will tell us where we stand. Some lighting protection may very well fix our ground grid problem as well. Perhaps I can return to this topic when I have some data and a better understanding. Good luck, for now, with your issues!