My house has a security system with integrated fire alarms. I knew there was a security alarm there, but only now do I realize that smoke detectors are part of the package. There are redundant battery operated smoke alarms mounted in roughly every location. The system seems to be 12v or 24v, and all devices seem to be wired into the central panel.
The
central panel consists of a 12v rechargeable lead acid battery, used to keep the system powered
even during a electrical service outage. In addition, the central station must have
all the programming in order to monitor the system and "alert
the authorities".
All this isn't ideal. In the modern world, people use TCP/IP networking and wireless devices for security. This is not that. Instead, this is a
lot of complicated and sloppy low-power wiring.
So, now I have to figure out exactly what this is, and if I should keep it or replace it.
The sad part is the history. The current system from ~2001 seems to have replaced an earlier system. The earlier system included a mess of speaker wire, telcomm wire, thermostat wire... you know, just about everything kind of scrap cable someone had sitting around. And all this old wiring goes into the modern alarm box, but is not connected to anything.
Related, throughout the building there seems to be wires just randomly floating around and disconnected.
I ended up labeling the cables in the box and took my trusty multimeter in "continuity mode" to identify each of the random cables. I'll keep the cables in place - maybe I can use them later, or someone else can rip them out. But at least there won't be mystery cables all over the place.
I was able to trace back all but one of the idle cables - a pretty common four conductor analog telecom-style cable. I haven't be able to trace this cable back because there are a lot of similar looking cables around. I hope to figure that one out, but that's a lower priority right now.