Simple security system install

[Giles]

I have a large barn with lean-to. I would like to install a motion detector inside the barn and one also in the lean-to. I would like to have these two sensors feeding a special light fixture along with a loud 120v 6" bell. I know that I can use separate light fixtures but I only have one security bell.
They will both be powered from the same breaker circuit. My question is if I wire both sensors to the single light and bell, will the current running back into the other sensor from the activated sensor cause damage? Would I need to install diodes or other electrical device?
Safety is of great concern.
Any suggestions are appreciated.

[jamiedolan]

I have a large barn with lean-to. I would like to install a motion detector inside the barn and one also in the lean-to. I would like to have these two sensors feeding a special light fixture along with a loud 120v 6" bell. I know that I can use separate light fixtures but I only have one security bell.
They will both be powered from the same breaker circuit. My question is if I wire both sensors to the single light and bell, will the current running back into the other sensor from the activated sensor cause damage? Would I need to install diodes or other electrical device?
Safety is of great concern.
Any suggestions are appreciated.

By 2 3 way motion sensors for $17 each at Lowes or *******. I believe the brand they carry is rated for non-lighting loads, but double check the package to make sure it is ok to install something other than just a light and that you are in the correct amp/watt range for the motion sensor.

Not sure if any of these are exposed to weather, if they are then you need to have a weather proof sensor, and not the standard wall sensor I am refering to.

Jamie

[Billy_Bob]

House electricity (120V) is AC or alternating current. Diodes would not work with AC, just DC for blocking. You could however use a relay or "contactor".

Note that security system devices are not rated to be used with 120V AC. Most of these are designed to be used with 6 or 12 volts DC.

And security system motion detectors are quite different from motion detectors used for outside lighting.

Security system motion detectors are designed to not give false alarms. Some use a dual technology infra red and microwave detection and both must detect movement before an alarm is sounded. Just one or the other has a long history of false alarms. (But with both, almost false alarm free.) And these are designed for 6 or 12 volts DC.

The outside light motion detectors which are designed for 120V AC are only infra-red technology and cheaply made. These would be prone to false alarms.

Also a security system "control panel" would sense a detector going off, then ring a low voltage bell/siren (6 or 12 volts dc) for a set amount of time like 10 minutes, then turn itself off and reset the alarm.

If using an outside light motion detector, the bell would ring for the amount of time the light was set to be turned on.

For more information about security systems, click on the following for forums where you can ask questions...
http://www.google.com/search?hl=en&q...earch&aq=f&oq=

[jennifer8055]

Hi,
If you're looking for a home security system you should check out http://usalarmcompanies.info . They give you a free complete comparison of the various home alarm system providers in the US and you can choose one based on the size of your home, your requirements etc.