How Does a Recessed Door Contact Work?

A recessed door contact works using a sensor and magnet. When the door is opened, the magnet will separate from the sensor. This will cause a reed switch inside the sensor to activate, and it will alert the system. A recessed sensor is inserted into the door and frame to remain out of view.

The benefit of a recessed door contact is that it is hidden from sight. This can result in a more aesthetically pleasing installation if the user doesn't want their door contact to be visible from the outside. However, the user will need to drill holes into both the door and its frame. The sensor and magnet are both inserted into these holes to hide them from sight. This can make recessed sensors more difficult to install than surface-mounted sensors, which do not require any holes to be drilled.

But really, recessed sensors do not work much differently than surface-mounted sensors. Both sensor types function using a sensor and a magnet. When the door is opened and the magnet separates from the sensor, a reed switch inside the sensor will activate, and the sensor will alert the panel. The only difference is that with a recessed sensor, the magnet and sensor are inserted inside the door and its frame. But with a surface-mount sensor, the sensor and magnet are both placed on the outside surface.

When installing a recessed sensor, we recommend inserting the sensor portion into the stationary door frame and the magnet into the moving portion of the door. This is so that if the door is ever slammed or ever forcefully opened or shut, then the sensor will be less likely to become damaged. Also the magnet and sensor should be installed no more than one-half inch apart. This is so that when the door is closed, the magnet will be in close enough contact with the sensor. This is very important for ensuring that the device functions properly.