Adding A Switch To A Door Sensor

Question

I have a double window or door; do I need to use two Door/Window Sensors? How can I add an extra magnet switch to a Door/Window Sensor?

Answer

It is pretty simple to add another magnet switch to a Door/Window Sensor. The sensor itself has two screw terminals on it. Normally, one magnet switch is wired to the terminals. Whenever the switch opens up or a wire is cut, the sensor sounds the alarm because power is not flowing between the terminals.

To add a switch to a sensor, unscrew one of the two terminals and take the switch wire out. Attach the free end of the old switch wire to one of the two new switch wires. Attach the other new switch wire to the screw terminal. You now have a loop of wire with two switches in it. If either switch is tripped, the alarm will go off.

You can call 800-675-3044 to purchase extra magnet switches. You can also substitute any normally-closed sensor (NC) made for a wired security system.