Burglar alarm wire connects all of the parts in hardwired home security systems. The main control panel is wired to keypads, burglar alarm contacts, motion detectors, sirens, etc.
Whether you’re comparing burglar alarm companies or DIY security systems, windows are key points of protection. They are secured most often using hardwire contacts.
For tips on running wire for magnetic door switches, see Burglar Alarm Wiring for Securing Doors.
For interior protection, see:
For an overview of wire needed for a complete security system, see this page on home alarm wiring.
Each movable (opening) window needs a 2- or 4-conductor alarm wire. Ideally, every window should be home run, and have its own wire back to the panel.
Fixed glass can be protected in one of two ways:
-Surface-mount shock sensors stick directly on the glass panes, and detect breakage through direct vibration.
-Audio Discriminators “listen” to the sounds in an area, and trigger when they detect the specific frequencies made by shattering glass.
I’ll cover these interior burglar alarm sensors on a separate page.
Sliding windows should have burglar wire run to the top or bottom of the moving panel, approximately in the middle. This allows you to create a vent zone if needed.
If running burglar alarm wire to these locations isn’t convenient, route the wire to the side of the opening. There, a surface-mount or recessed magnetic alarm switch can be installed along the vertical part of the window frame.
Details on magnetic reed switch installation.
Vertical hung windows should have burglar alarm wire run through the side of the framing, if possible. If there’s not enough room on the side, bring the wire out at the bottom of the frame.
Casement or crank-out windows come in many varieties. They swing out horizontally by a crank, and can be single or in pairs.
Steel casement windows are found in many older homes, and need to be considered carefully. The frames are built with heavy steel and cross-members, into which the glass panes fit. This framework is very strong, making it nearly as tough to break into as a set of security bars.
Trying to install burglar alarm wire and switches on steel casement windows is, to put it simply, a nightmare.
There are several reasons:
-The steel is hard to drill, making it tedious to route a burglar alarm wire to the switch;
-Steel sucks away the strength of magnets, reducing the gap distance and making the switch prone to false alarms in the future;
-Metal frames are so heavy that they almost always sag greatly with time. This makes them hard to open and close, and leads to huge misalignments between switches and magnetic contacts.
The solution? Don’t run burglar alarm wire to these windows at all. Instead, wire for a motion detector and/or a glassbreak sensor to protect each room. An burglar will generate more than enough noise and movement getting through a casement window to trigger either of these sensors.
Wood casement windows are a dream to work with, compared to steel casements.
Wooden frames don’t sap the strength from alarm magnets, so you can easily get a good gap distance with typical magnetic switches.
Wooden casements usually have a generous gap below the sill area which contains the cranking mechanism. This is a good spot to run alarm wire for a surface mount switch. The magnet can then be attached to the swinging portion of the window, in line with the switch location.
For wood crank-outs that don’t have much space at the bottom, a wire for a recessed burglar alarm switch can be drilled into the bottom of the frame. A surface-mount magnet attached to the bottom of the swinging portion will trigger the switch.
Awning windows are hinged at the top, and swing out at the bottom. Run alarm wire to the bottom or side of the frame, whichever has the most room for a switch and magnet. Watch out for the metal guide rails along the sides of many awning panels, since they will often interfere with a surface mount magnet.
For convenience, openings that are grouped closely together, such as a set of bay windows, can be looped on the same run of alarm wire. I recommend looping no more than two or three windows on one wire, to make service easier in case of a failing switch or other problem.