Four years ago, I installed a full-perimeter hardwired security system in our house. This probably ranks as the single largest DIY project I’ve ever undertaken. All told, it took me about four months, working alone, and splitting the time with my day job as well as household chores and other projects. Would I do it again? Actually, now that I have kids, I’m not even sure if I could do it again. It ate up almost all my spare time even without kids. I think my wife was about ready to divorce me. But, in the end, we have a great, professional grade, monitored system, and I have full control over it to make changes, upgrades, etc., which brings us to the actual topic of this entry. I’d like to add a few zones (for a very basic intro to alarm system terminology, see this FAQ) to the system, but I’m running out of expansion room. Because of the layout of our house, I laid the system out in sort of a star topology; the panel is near one end of the house, and I have a “zone expander” installed near the other end. Each zone is terminated at either the panel or the zone expander, depending on which is closest. The zones I’d like to add are near the zone expander, but the expander (which provides 8 zones) is full. Matter of fact, it’s overloaded — in a couple spots, I’m doubling up devices which really should be on separate zones, becuase of the lack of space. Not only that, I’m up against the maximum auxiliary power load that my panel supports. If I add any more powered devices (motion detectors, glass break detectors, sirens, etc.), the panel will be overloaded in that department too.
So, before I do anything, I’m going to need to upgrade the system to allow for the additional zones and power draw. Here’s the current plan:
- Install an additional zone expander and mount it near the current one, to provide 8 additional zones.
- Install an auxiliary power supply and battery to handle additional powered devices.
I’m hoping I can fit all of this gear into a single metal enclosure. If necessary, I can move the existing zone expander, which will requre splicing several wires, but shouldn’t be the end of the world. The shopping list then becomes: metal enclosure, zone expander, power supply, battery, and extra wire, for a total price tag of around $250. Of course, these days, the real cost includes finding time to do this, as there are a lot more demands for my spare time these days. I’m thinking this project probably won’t get off the ground until close to the end of 2006. But we’ll see.