Electrical question - adding a neutral

Page 1 of 3  
I recently purchased some motion sensors to control the lights in our hallway. There are three locations where they will be installed. These sensors, Pass & Seymour RW3U600, require a neutral and one location has no neutral.
Can I bring a neutral from a nearby receptacle that is on a different circuit or must the neutral be the same that is used by this lighting circuit?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 21 Mar 2013 09:09:10 -0500, Gordon Shumway

No. The neutral needs to come from the circuit supplying the outlet. It must be in the same cable or raceway.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/21/2013 11:21 AM, snipped-for-privacy@aol.com wrote:

I'm guessing this is a switch leg? do you have access from the attic?
additional complication - you state "hallway" singular but "locations" plural. This implies to me that you have at least three switches controlling one light or group of lights. That means that these motion sensors should be 3-way or 4-way type with the one in the middle of the run being a 4-way. The spec sheet for this devices lists it as 3-way not 4-way.
https://images.tradeservice.com/9ETBOIYK8205G6UU/ATTACHMENTS/DIR100014/PASSEME00672_3.pdf
Additionally if the device requires a neutral you would need to run the neutral to all three locations, not just the closest one, which means you may have to source some 4w+G Romex and may be running into box fill problems... not saying you can't do this, but you might be looking at a bigger project (e.g. breaking the boxes out of the wall, replacing with deep boxes, repulling wire) than you originally thought.
Have you sketched out the wiring for the light and the three switches as it exists now? If you could post that on photobucket or something we might be more help.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

If I understand the definition of "switch leg" correctly the answer to your question is no... I think. These switches control the ceiling lights in two intersecting hallways. The "intersecting hallways" answers another question of yours.
The spec sheet does say only 3-way but their web page says 3-way and 4-way and their tech support claims as many as six (6) sensors can be wired together to control one light or group of lights.
http://www.legrand.us/passandseymour/motion-sensors/3-way-occupancy-vacancy/rw3u600la.aspx#.USUteGcWSSo
Currently the only location that has no neutral is the location where the 4-way switch is located. The location where the load is connected to has a neutral but it is from a different circuit as well. That's why I only asked about the one location.
I do have access to the attic. It does appear that I have a lot more work ahead of me than I planned. Crap.
I have up loaded two images to photobucket.
http://s692.photobucket.com/user/dobripw/library/Wiring%20Schematic?page=1
One shows the wiring as it is today and the other shows how the three sensors will be wired. If you see anything that's wrong let me know.
Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

http://www.legrand.us/passandseymour/motion-sensors/3-way-occupancy-vacancy/rw3u600la.aspx#.USUteGcWSSo

*I looked at the diagram of the existing circuit and it doesn't seem right to me. Normally one box would have a two wire feed and a three wire that goes to the next box with two travelers and carries the neutral along with it. At the other end should be a two wire that goes to the light fixtures and the three wire with travelers and neutral. You are showing the neutral going to the lights all by itself. The four-way switch should have two sets of travelers and the neutral passing through.
Regardless, I had a thought. Since these are motion sensors they don't need to be three-way. Perhaps you could just wire single pole units at each location. You would just need to change some of the splices in the existing wiring to make sure that you have a neutral, hot, switch leg, and ground at each location. Basically putting all of the sensors in parallel. You would lose the ability to turn on at one location and off at another manually.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 21 Mar 2013 17:58:53 -0400, "John Grabowski"

John you can also wire a 3/4 way switch loop with the hot going down and the travelers coming back. (or the other way, travelers going down, switched leg coming back)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

*Yes, but based on the wiring diagram the OP presented, I'm not sure what he already has in place. He is only showing a two wire in and a two wire out at the 4-way. Maybe that is why a neutral at the load side was borrowed from another circuit.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/21/2013 07:24 PM, snipped-for-privacy@aol.com wrote:

I'm thinking that this is actually a hybrid of that and the standard configuration, since the OP said that there were neutrals in two of the boxes but not another - panel box -> switch 1 -> switch 2 -> light fixture -> switch 3
so if that is the case he will have to repull the cable between the light fixture and switch 3 but that is just supposition at this point
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/21/2013 03:58 PM, Gordon Shumway wrote:

http://www.legrand.us/passandseymour/motion-sensors/3-way-occupancy-vacancy/rw3u600la.aspx#.USUteGcWSSo

Something's not right here. If your sketch is correct then by the NEC the neutral must be present in the "family room" switch box because the sums of the currents in a given cable/raceway must sum to zero.
You sure it's not a switch leg, or that your diagram is accurate?
(I'm not saying that you're wrong, just that *something* is wrong...)
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I am definitely NOT sure it's not a switch leg. I am positive both diagrams are correct. The sensors work as they should when I temporarily borrowed an existing neutral at the two locations that didn't have it for that circuit.
We bought the house when it was new forty years ago. Did the NEC require a neutral at the family room location then?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/21/2013 10:42 PM, Gordon Shumway wrote:

There are situations where a neutral may not be required to be present, but if your diagram is accurate then it is. The requirement (prior to the current NEC) is not that the neutral to be present, but that all the conductors in a cable sum to zero (to minimize potential inductive heating.) So the neutral needs to be present in the cable running from the "hallway" switch to the "family room" switch and likewise from the "family room" to the "foyer." Otherwise let's just say for the sake of argument that it's a 120W light bulb to make round numbers, you'd have 1A flowing through the "hot" traveler in each cable and no current in the disconnected traveler - that doesn't sum to zero. Likewise you have a neutral with a -1A current somewhere else. (I know it's AC, I'm just using the convention of "hot" = positive and "neutral" = negative for purposes of simplicity, since the currents will in actual fact oppose each other at all times) That's not legal...
However, disassemble the family room switch box again. If your diagram is truly correct, the neutral should be there, and spliced through (likely with a wire nut, if the house is only 40 years old) hidden in the back of the box.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I have done some more investigation and have discovered I could be wrong. I can't believe I said that. Thank you Nate, for encouraging me to look deeper.
My original conclusion was the wires going to the load originated at the box in the foyer I believe is wrong. The wires going to the load originate in the hallway.
I have uploaded a revised image to:
http://s692.photobucket.com/user/dobripw/media/Wiring%20Schematic/Schematic-PampSRW3U600Revised.png.html?sort=3&o=0
What is the red wire going to all of the boxes and presumably the load?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 3/22/2013 6:02 PM, Gordon Shumway wrote:

http://s692.photobucket.com/user/dobripw/media/Wiring%20Schematic/Schematic-PampSRW3U600Revised.png.html?sort=3&o=0

the load. There should only be two unless they're carrying a feed to go somewhere else. The red wire, the way you drew the diagram, would be the common, and would just be spliced through at the 4 way.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

http://s692.photobucket.com/user/dobripw/media/Wiring%20Schematic/Schematic-PampSRW3U600Revised.png.html?sort=3&o=0

*Much better. The red wire appears to be the load as it is spliced through to the last 3-way and should be attached to the darker screw on the 3-way switch. As RBM pointed out, the three wire going to the lights has a line, load, and neutral wire. It is also possible that the hot and neutral comes from the light to feed the switches and the red is the load returning to the light.
Based on the diagram that you provided from Pass and Seymour, you may be able to install the 3-way motion sensors after changing the splices so that you have a hot (Black), neutral (White), and traveler (Red connected to yellow) at each box. The load (Red connected to red) gets spliced at the one box. This appears to be a digital control and not entirely mechanical which would require a fourth load wire at each location.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

And if that one won't work under those conditions, Lutron Maestro series has a multi location dimmer that include a motion sensor, will work CFL, etc, requires only hot, neutral and one wire between switches and you can hook together up to 10 of them that way. That series of dimmers is really nice.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/22/2013 06:02 PM, Gordon Shumway wrote:

http://s692.photobucket.com/user/dobripw/media/Wiring%20Schematic/Schematic-PampSRW3U600Revised.png.html?sort=3&o=0

Looking at that now, if the white is one of the travelers in all boxes, it would appear that the whole thing is a long 3-way switch leg with no neutral. I think at this point the next step is to drop the light fixture and see what's in there. The only thing that doesn't add up now is the red in the cable going to the load, that only needs to be a 2-wire cable (by the old code.)
What I suspect that you'll find is the line coming into the ceiling box, a 2-wire cable going to the first switch location, then a 3-wire cable (I'm not counting grounds in any of this) going to the other two switch locations.
The red wire in the 3-wire cable, and then one of the wires in the 2-wire cable (I've seen it done both ways) will be the switched hot returning from the last 3-way to the load in the ceiling box. the other wire in the 2-wire cable is unswitched hot.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 03/23/2013 09:42 AM, Nate Nagel wrote:

This might make what I was suggesting more clear.
http://i1058.photobucket.com/albums/t402/thatguyN8/switchleg_zps48938a86.jpg
Unfortunately, if I'm right, you've got three runs of cable to repull.
(my apologies for quick and dirty sketch, but for things like this I'm far more comfortable with a drafting pencil and cocktail napkin than a computer program...)
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

*I see no reason to pull any new wires. Based on the information that Gordon has provided, he has the necessary conductors. He just needs to change a few splices. He needs to connect all of the whites together in the box with the line and load which will give him a neutral at each location. The blacks get connected together to provide a hot at each location. The existing red wire that goes from switch to switch gets connected to the yellow on the motion sensor. The red on the motion sensor in the box with the line and load gets connected to the red going to the lights.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 3/23/2013 7:58 AM, Nate Nagel wrote:

I don't think the details, including switch connections are shown correctly at the right end box. Is there only one (3-wire) run? The wires (but not connection) make sense if there is another 2-wire connection and power feeds through the box. Otherwise, as Nate says, there only need to be 2 wires to the light.

*IF* the number of wires shown is correct the P&S devices can be used. As John notes, these are not normal 3-way switches. Contrary to the labeling on the P&S diagram, The sensors interconnect with a hot, neutral and control wire. The singe control wire switches the devices between on and off. There need to be 3 wires between devices (which there are). At the right end feed point there need to be 3 wires (hot, neutral and switch leg) to the light, which is what the diagram shows.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 3/23/2013 12:53 PM, bud-- wrote:

http://s692.photobucket.com/user/dobripw/media/Wiring%20Schematic/Schematic-PampSRW3U600Revised.png.html?sort=3&o=0

lights, it's either got to be bringing a feed and switch leg up from the switch or down from the lights, either way the devices will work as John describes
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.