Motion Sensors

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Next Generation

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I have a job coming up where I am installing ceiling mounted motion sensors. The are above the ceiling is the cold air return. I understand that all cables and cable ties need to be Plenum rated. Can I make my low voltage terminations without a box? If I am able to do this do I need a special type of wirenut?
 
Next Generation said:
I have a job coming up where I am installing ceiling mounted motion sensors. The are above the ceiling is the cold air return. I understand that all cables and cable ties need to be Plenum rated. Can I make my low voltage terminations without a box? If I am able to do this do I need a special type of wirenut?
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Please read article 725. If you are talking class 2 wiring, you don't need junction boxes. You should use them.

Are wirenuts plenum rated? Good question, but if you put you junctions in a box, it's no longer a question.
 
Another comment about junction boxes: make sure to read the specifications carefully. Some engineers spec out using junction boxes in such applications; alternatively, the client may have in-house specs or design guidelines that require using boxes.
 
Is there a voltage or current or power low enough that you don't need wiring splices to be enclosed in fire resistant boxes?

10 V @ 10 mA comes to mind. This was some commercially available device.
 
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G._S._Ohm said:
Is there a voltage or current or power low enough that you don't need wiring splices to be enclosed in fire resistant boxes?

10 V @ 10 mA comes to mind. This was some commercially available device.
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Technically any CL2 and CL3 wiring.

Its somewhere in NEC 2008 article 725.130 I believe.
 
yea 2008 725.130(B) the conductors have to be insulated but not a chapter 3 wiring method, on the load side of a CL2, 3 power supply.

The line side of a CL2,3 or CL1 must be a chapter 3 wiring method 725.130(A)

That's not the most eloquent answer, but I am tired. Good night forum.
 
nhfire77 said:
Please read article 725. If you are talking class 2 wiring, you don't need junction boxes. You should use them.
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many of the occ. sensor power packs aren't designed for the LV side to be installed in a junction box. usually there is a 1/2" nipple on the 120v wiring that can be installed in a junction box.

some of them say you can install the entire unit inside a junction box, but then you have 120v and 12v terminations inside the same box, and they can be a beast to fit inside the box anyhow.

and then there's the matter of getting the occ. sensor nipple into that box also.

unless the OP is using 120v occ sensor; in that case, disregard my statement above.
 
Installed in CAR?

Installed in CAR?

Next Generation said:
I have a job coming up where I am installing ceiling mounted motion sensors. The are above the ceiling is the cold air return. I understand that all cables and cable ties need to be Plenum rated. Can I make my low voltage terminations without a box? If I am able to do this do I need a special type of wirenut?
Click to expand...

Might not be a good idea to install a Motion sensor in the CAR especially on the ceiling. Depending on how big the return grill is, vibration can set off a motion sensor due to resonance. Second, the sensor may need a clean field of view to cover the area being monitored. I take it this is for security reasons to turn on a video or an alarm?

There are alternate methods that can be used...such as an IR sensor that is available as a fake wall receptacle. The IR includes an X10 unit that triggers the remote monitor through a branch circuit as a power line carrier that connects to somewhere else in the house for a recording or alarm unit. You can use an RF transceiver also. These methods eliminate running LV through the house by locating the devices at standard 120V receptacles that are not on AFCI lines that need filtered coupling.
 
gndrod said:
Might not be a good idea to install a Motion sensor in the CAR especially on the ceiling. Depending on how big the return grill is, vibration can set off a motion sensor due to resonance. Second, the sensor may need a clean field of view to cover the area being monitored. I take it this is for security reasons to turn on a video or an alarm?

There are alternate methods that can be used...such as an IR sensor that is available as a fake wall receptacle. The IR includes an X10 unit that triggers the remote monitor through a branch circuit as a power line carrier that connects to somewhere else in the house for a recording or alarm unit. You can use an RF transceiver also. These methods eliminate running LV through the house by locating the devices at standard 120V receptacles that are not on AFCI lines that need filtered coupling.
Click to expand...

Most video surveillance systems now have image motion detection built right in the DVR so motion detection is a thing of the past for surveillance systems, but I believe the OP is talking about controlling lights, which the Leviton power pack relay can be mounted right in the fixture canopy, or switch location and a 18/3 conductor CL2 plenum rated LV cable routed to the fixture is all that is needed.

Leviton has a selection of options to fit most needs, and systems can be combined to control more lights, such as warehouses when you don't want only one light to come on at a time, most of the gas stations and or conievance store bathrooms I do, I used the 360? Leviton ceiling system, It gives me allot of flexibility and there very good about not shutting off the lights when someone is in the bathroom, hubble also make a good system that is very simular to Leviton
 
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