mounting motion and glass break sensors

[jleach8]

I am doing the wiring in my new house now, just wanted to make sure on this...

Do I need single gang boxes behind the motion sensors or is it good enough to just pull the wire through the sheet rock before surface mounting? I purchased the Bosch ISM-BLP1-P.

For glass breaks I bought these: http://www.automatedoutlet.com/product.php...at=0&page=1
It's not completely clear in the manual whether or not the round model needs a box or not.

Thanks!

Jamie

 

[BraveSirRobbin]

I am doing the wiring in my new house now, just wanted to make sure on this...

Do I need single gang boxes behind the motion sensors or is it good enough to just pull the wire through the sheet rock before surface mounting?

I actually used both methods, and I can't really say one is better than the other as both worked out well. If you are not going to use a box, just make sure you have a generous loop "lightly" attached to a nail on a stud and take pictures/measurements of its location before drywall.

You can get into some tricky mounting scenarios with the box also as you will have to do some light modifictions to a cover plate to mount your detectors (again, not a big deal).

 

[jleach8]

I am doing the wiring in my new house now, just wanted to make sure on this...

Do I need single gang boxes behind the motion sensors or is it good enough to just pull the wire through the sheet rock before surface mounting?

I actually used both methods, and I can't really say one is better than the other as both worked out well. If you are not going to use a box, just make sure you have a generous loop "lightly" attached to a nail on a stud and take pictures/measurements of its location before drywall.

You can get into some tricky mounting scenarios with the box also as you will have to do some light modifictions to a cover plate to mount your detectors (again, not a big deal).

Instead of relying on the pictures, won't most drywall contractors just pull the wire through when they put up the drywall? I was planning on using that method for flush mounting the Elk KP2 keypads with the ELK-M1BBK2 back box.

Thanks

 

[gatchel]

Typically most glass break sensors and motion detectors will need some sort of plate to fully cover a single gang box. I would just pull the wires through the wall. You can always add a low voltage ring later by cutting the drywall after the fact if you need to. The key is to locate the wire in a fashion that is can be hidden by the sensor easily when it is mounted. (corner Mount motion for example)

Edit:

The Bosch sensor you mentioned is 4.2 in. x 2.4 in. x 1.9 in. The single gang light switch plate in my nearest room measures 4.5 high by 2.75 wide. Mounting that motion on a single gang box would probably leave a visible gap around the edges depending on how accurate the drywall is cut to the box.


The dimensions are located on the data sheet here:

http://www.boschsecurity.us/index.aspx?prdctid=2976

 

[BraveSirRobbin]

Instead of relying on the pictures, won't most drywall contractors just pull the wire through when they put up the drywall? I was planning on using that method for flush mounting the Elk KP2 keypads with the ELK-M1BBK2 back box.

I guess I'm not sure. Probably depends on the contractor. The thing is though, you will have a wire sticking out until you get your system in place (I'm fine with that, but worry about the WAF)!

 

[jleach8]

Yes WAF is a concern. I was just concerned about having the sensor not cover the box, in a corner mount for example.