I have an outbuilding on my property that I would like to monitor for fire and security through my M1 system. My plan is to install a P212S power supply and a M1XIN input expander in the building and wire it back to the main control via an underground cable – the total length would be around 100′ with about 50′ of it underground. I would only need to connect up the Negative, Data Bus A, and Data Bus B wires to the P212S power supply back to the main house, but my concern is with running the cable underground, the potential for lightning strikes causing a surge on the data bus. What would be the best practices to minimize and surges on the underground cable? Surge suppressors for one, but what about the cable itself or installation techniques that would minimize issues? There are plenty of surge suppressors out there, the ones from Elk seem to be mainly for POTS lines.
My other thought is to just install a totally separate, inexpensive, system out there and not even go through my M1 – maybe just monitoring for a general alarm condition via an isolated relay to electrically separate everything. But it would be nice to know exactly what is going on in the building.