Alarm Contacts- Contact switches are magnetic switches used to protect doors and windows for the most part. There are three main styles that are used by most alarm companies. They are recessed contacts, surface mount contacts and roller-ball contacts.
Recessed contacts are hidden in the window tracks and door jams so that they can't be seen when the window or door is closed. The switch is on the fixed or non-movable side of the opening and a magnet is placed on the movable side. When the magnet meets the switch the circuit is complete and the control knows it is closed. Recessed contacts are more complicated to install unless they are placed during the construction phase of your home or business. A good installation technician can install recessed contacts in your home after construction as long as they have an unfinished basement, accessible attic or closet to run the wires in.
Surface mount contacts function the same as recessed ones however they are visible when the doors or windows are closed. They come in three main sizes being large, small and micro. They come in the colors white, gray and brown so they can blend in to the door trim or window- sill they are mounted on.
Roller-ball contacts are in the hinge side of your door jam and the spring- loaded ball is pushed in when the door is closed completing the circuit. These are more likely to need replacement in a few years as they are considered a moving part.
All types of recessed and surface mount contacts can be hardwired directly to your control panel or you can get them in a wireless version. Wireless contacts have a transmitter tied to them or built into them that sends a radio signal to a receiver in the control. The transmitter is surface mounted and comes in two colors, white and brown. If white and brown are not your desired colors, you can paint the switches and transmitters to match your decor.
Doors are the most common point of entry and should be protected by your system. I always recommend contacting every perimeter door in your home or business
Window contacts can add up in a hurry as most homes have many windows. I have always felt that window contacts give the homeowner a false sense of security because of the fact that a window has to be opened in order for them to work. If your window is locked (and it should be) when you are away or sleeping, a burglar has to break the glass or remove the glass to unlock it. If they break the glass and the alarm does not sound, why would they open the window? Instead they would most likely clear the broken glass and climb in. That is why your money is better spent on motion detectors and/or glass- break sound detectors.
If you have children, window contacts can be a valuable tool. They will keep your youngsters from opening the window for a stranger. And they will also make your teenager sorry you ever read this. (If they tell you all they want for the holidays is a magnet, the jigs up!) Window contacts are often better at keeping people in than they are at keeping burglars out. If you do choose to use window contacts you may like the fact that the surface mounted versions can be set up so that you can keep your window open a few inches for ventilation and still be armed.
Matthew Francis Alarms@expertsknow.com
22 year veteran of the alarm industry
Installer, salesman, licensed alarm company owner, monitoring station designer, promotions and marketing director with one of the worlds largest security dealers. He now works as a consumer advocate, teaching consumers how to buy or get systems for free (without being taken). He is committed to being unbiased.
His web site is http://www.expertsknow.com