The house I bought three years ago has an ADT security system. We want to remove it. It's a basic system - three motion sensors, two door sensors, and four window sensors. Most of the sensors were broken during remodeling.

I found a transformer in the basement and disconnected it. That set the control panel beeping, so I cut the wires to the panel to shut it up.

The motion sensors still have power. Are there generally multiple transformers in a system? Or do the sensors have backup batteries in them?

There must be a hub somewhere for all of the wires from the sensors. I expected to find this either near the transformer in the basement or near the panel or siren, but I don't see it. Where do all of the wires from the sensors go? The panel and siren each have one 22 gauge twisted pair wire attached to them. This wire supplies power and must also carry signals from the sensors or a hub.

The system appears to be tied into our phone lines, but I don't see where that happens either (I see where they spliced into a phone wire and I see it disappear into a wall, but I don't know where it ends up). The phone connection disrupts our DSL internet connection because it isn't filtered.

Can anyone give me pointers to how these things are generally installed? I'm trying to follow the wires but some clues to what I'm looking for would help.

 

Systems generally have an alarm control panel located in a central closet or master bedroom closet. This control panel is powered by a plug in transformer and has a backup battery inside the enclosure. All keypads, motion sensors, door contacts, sirens and phone connections run back to this control panel.

If you pull the transformer out of the outlet the battery will last for hours until it runs down. The phone connection is usually a block inside or beside the control panel in the closet. It has a normal looking phone plug only a bit larger than typical.

 

So are you saying that there would generally only be one transformer and that all of the other wiring would run to a point near this transformer? I guess I have to start tracing the wires to figure out where they all go. I'm guessing that there's something hidden in the suspended ceiling. There's nothing visible in any of the closets.

 

The transformer only has one wire, just like a lamp or radio. The transformer is the AC power for the entire alarm system. Sometimes if there are too many powered device for the panel to support they will install a backup powersupply just for all the extra devices, glassbreaks motions and the like. Then there may be two transformers. A panel can handle quite few powered devices no problem.
The wire from the transformer will run back to the control panel. The control panel is the central brains of the security alarm system. It controls everything. All wired device in the house will run back to this control panel. All windows, doors and keypads will return to the control panel. In the attic there will be a large bundle running to the control panel. If you had 20 doors/window and 3 keypad that would be a fairly big bundle of wires.

In the systems I have installed only the installs that had made allowances for the alarm system were the transformers near the panels. Most times they are located in an attic or garage ceiling , plugged in with the OHD opener just cause its an easily accessed plug.

Some really old systems have a 2 foot wide keypad that is the control panel in itself and the battery would be behind this large keypad.

 

a metal box about the size of a shoebox, usually mounted inside a closet, hall closets and master bedroom closets are popular choices. Inside this box will be a circuit board and a 12V sealed lead-acid battery.

First, disconnect one of the wires from the battery, doesn't matter which one.
Next, look along the bottom of the circuit board, you should see a bunch of screw terminals. You're looking for the pair marked "AC input, AC power" or something close. Back off one of those screw terminals until you can pull out the wire. Put electrical tape on the wire so it doesn't short out accidently. The alarm system is now powered down and de-activated.

You may have damaged the control panel or boxes' circuit board for the alarm sytem when you cut the wires, please keep this in mind when or if you decide to use it again. Also, when powered back up, it will show troubles/ faults for time not set and possibly low battery-just something to keep in mind.

Hope this helps!

 

Thanks for the help. I finally found the control panel. It was hidden behind a cabinet above the outlet the transformer was plugged into. I had to take down the cabinet to get to the panel. It wasn't very accessible, but I guess that's the point.

I wouldn't have known what to look for without you guys, so thanks again.

 

Wow! That has to be one of the more thoroughly hidden panels I've yet to hear of. I've seen them _in_ cabinets, but behind one is new.

 

That is so wrong, no wonder he couldn't find it. A tech would have had major trouble serviceing that system. Glad we could be of some help.