Running control cables to switch boxes

[Ira]

Still trying to decide what all to do while the walls are open, and didn't see anything in the wiring guide about this...
 
One of the things I'm doing is making sure that all boxes containing a switch have a neutral wire. I had wired quite a few switches using just switch legs 25 years ago, so I'm "fixing" that issue.
 
I really don't foresee ever using a type of HA solution that requires control cables to be located at each switch, but while the walls are open, it would be really easy/cheap/fast to at least run a cat6 wire from each switch to the nearest point that is easily accessible in the attic. However, I don't know squat about the systems that use this type of wiring, so...
 
1. Does the line voltage wiring require special wiring techniques, e.g., home running all the switches? I don't want to redo a lot of the house's wiring for this.
2. Is there any benefit to running control cables to outlet boxes or light/fan fixture boxes?
3. What type of electrical box is typically used in this scenario, and can it be used without looking different than the normal box when the control cable is not being used?
4. Can the control wire be run thru the same holes as the line voltage cable (all Romex, in my home)?
5. Can cat6 be used for this purpose? If not, what should be used?
6. Would you (or did you) run these cables even though you had no current plans to use them?
 
Thanks,
Ira

 

[wkearney99]

First off, don't plan on ever having electronic equipment in an attic space.  The heat up there is too much for most gear.  Always aim toward being in the same conditioned air as the rest of the house.  Plan to run things to a main rack somewhere, but always in conditioned space.  Not an attic, garage or crawl space.  Temp and humidity are killers for electronic gear.
 
It's most common to run 18/4 and at least one CAT5E line (I prefer two) to each place where you'd want a wall control for whole house audio.  Then run 18/2 from there to each likely in-ceiling/wall speaker location.  Some systems will power the speakers all the way back from the central rack.  Others will amplify it at the keypad and power the speakers from there.  Either way you've got wiring in the walls ready to deal with either scheme.
 
Low voltage wire, by code, cannot be run into the same enclosed junction box as line voltage.   There has to be physical separation.  This can be in the form of a 2-gang box with a plastic divider.  Or a two gang faceplate with a single enclosed box for line voltage and the back of the second side open for low voltage use.  I have the latter for wall outlet positions (power on one side, Ethernet on the other)
 
CAT6 can be used, but honestly CAT5E of decent quality (not cheap copper clad aluminum; CCA) is likely to be more than sufficient for residential purposes for decades to come.  CAT6 brings along the requirement for more stringent attachment methods to the plugs, which are themselves more expensive than CAT5E counterparts.  I put CAT6 into places where "a considerable amount of bandwidth" might be necessary in the future.  Like behind each 'big tv' or to office desk locations.  Otherwise it's CAT5E everywhere else.
 
I ran far more wire than I'm ever likely to "need".  In several rooms it turned out to be a good idea, as the locations I'd planned to use didn't turn out to be the ones that got used.  TV on this side, not that side, etc.  This is hard to plan for with new construction since you don't know how you're going to actually use a space until you're in it 'for a while'.
 
Any location that might ever have a ceiling fan should be wired with 3 conductor wire (black, white, red) back to the wall switch.  This way you can provide either dual switching or constant power and 1 switch to the canopy location.  I don't know that I'd bother running any CAT5E wire to fan locations.  Maybe for locations where you know you'd want to put a WiFI access point, but that's hard to predict ahead of time.  
 
What's MOST IMPORTANT is TAKE PICTURES any time you have walls open.  LOTS OF PICTURES.  That way you can determine how to best run wire later, if necessary, after the drywall is up.

 

[Del91574]

I would honestly bury the cable in the wall next to the switch box and use a sidecar style box if needed. Hell of a lot nicer finished product and no funky half blank plates if they're not used.

Only caveat would be if spray insulation was being used.
 
Most common would be either a 16 or 18/4 OAS and category cable.
 
Technically speaking, you must separate the cables unless the jacket insulation is rated for the same voltage. That means boxes, enclosures, bored holes, etc. There's grey and loophole areas to this, but the easiest way is to separate the voltages and systems, either by a separate box, a divided box or a sidecar box added to the HV box.
 
Unless the house or switch location was impossible to get to after the fact, I probably wouldn't run them unless I had a system picked out or was looking at centralized loads.

 

[pete_c]

Here for the zoned audio ran 16/4 and catxx to a new autonomous 4X4 ring in every location that had a pair of speakers. 
 
I put these boxes / rings next to the light switches in every room with speakers (IE: every bedroom / bathroom on the second floor)
 
From the box ran 16/2 to the in wall speakers. 
 
It made for a busy wall as the original electric was a single mud plate over a 4X4 box such that I put in a double metal mudplate for two decora switches (every room had a fan light / power and 1/2 of the outlets were switched)  No LV was brought over to the HV boxes.
 
I also ran 22/4 to the ceiling for occupancy sensors and 18/4 for smokes / CO and 22/4 for wall mounted PIRs and 16/2 for ceiling speakers.  Easy to do on the second floor via the attic but difficult to do on the main floor ceilings. 
 
I did utilize an LV key switch for a solenoid for a HV motor relating to the chandelier lift (garage door like motor in the attic).

 

[wkearney99]

I may have run 16/4.  I can't remember exactly.  I do know that a few of the runs resulted in just over 100' of wire length, so I ran heavier gauge to lessen voltage drop.

 

[Neurorad]

Run empty conduit (1.5") to all potential TV locations, to the attic or crawlspace. Plus 2" conduits from attic to basement. Tech changes, futureproof.

 

[Del91574]

Run empty conduit (1.5") to all potential TV locations, to the attic or crawlspace. Plus 2" conduits from attic to basement. Tech changes, futureproof.

Not necessarily allowable per code/AHJ. Raceways must be firestopped/draft stopped. Most locales recognize the IRC or use the IRC as the basis of their own statutes.
 
 International Residential Code (IRC) section R602.8 it explains that firestop is required in basements:

1. to form a fire barrier between stories.
2. to separate wood-framed vertical chases from horizontal chases including soffits, drop ceilings, and cove ceilings, etc.
3. in walls, every 10 feet minimum.
4. at openings around vents, pipes, ducts, cables, and wires at ceiling/floor level.

I'll give Pete and Chicago a pass (code requirement for conduit).

I've seen conduit allowed and I've also seen it fail a rough. Also have seen the AHJ require the conduit terminate at a box or enclosure and not be left bare or plugged with putty/caulk. If the OP is intending on doing this, either ask the question specifically before running the raceway or I'd pull a CatX. Doubtful the UTP is going to become obsolete in our lifetime. Too much of it out there and too many other ways to adapt it to do what we need it to do. Might not be ideal in 20-30 years, but that's to be expected.

 

[Ira]

My home is in a rural area, so I don't have any electrical inspections. However, the electrician doing the work is supposed to be following the latest codes. We haven't discussed the low voltage stuff yet, so I haven't asked his opinion on this.
 
My house is single story, no basement, on a concrete foundation. Combination of 8', 9', and 10' high walls. Attic over entire living space. Some walls (mostly 10' exterior ones) have wood horizontal fire stop blocks at 5' off the floor. Most don't have anything.
 
What must be done to follow code if I want to run empty and/or non-empty conduit smurf pipe in a wall cavity for future use for LV wiring? I know I need to seal the openings between the pipe and the top plates. Does anything need to be done at the top of the pipe, or can it just be left open in the attic?
 
Tried google'ing this stuff but everything I found was for commercial/industrial buildings. 

 

[Neurorad]

If you have attic above every wall, it will be relatively easy to retrofit any cables needed, if you don't use spray foam insulation.

 

[pete_c]

Yeah here ran cables and didn't utilize smurf tubing for LV building a chase from the basement to the attic.  I used the in wall speaker cavities lining them up on the 2nd to the 1st floor to help a bit running wire.  I used expandofoam after running the wires in all of the chases in the attic to the basement, attic to the second floor and basement to the main floor and main floor to the main floor ceiling side stuff.
 
I have helped peers with new construction and many went with smurf tubing and skipped wiring / purchasing LV wires. 
 
One friend wanting every kind of LV wiring never has installed any leaving only a few catxx cables in place. 
 
Personally I would rather have the LV wire in place and have it waiting to be used as an impetus to getting it done faster if the want is there; but then too I am very process oriented.
 
Looking at a new endeavor post construction fuse panel with conduit and noticed while the electrician GC was very neat and cheap.  He put in as many HV wires in conduit as he could fit and ran the conduit out of the front of the panel on the top/front and lined up the conduit very neat but didn't allow addition conduit (easy like) and ran conduit across studs in many areas rather than going up to the attic or down to the basement runs which I personally think was mickey mouse; but that is me.  Wondering if it was some sort of electrical GC dyslexia between floors / conduit (orientation)?
 
There the electric was romex and the fuse panel was in the garage and no electric had been n to the basement section of where the patch panels were at.  The drywall had been finish so I had to cut some running two romex cables from the basement to the garage fuse panel which worked but was a PITA.  I added electric / circuits to my garage using conduit home running it to the fuse panel and it was much easier to install the wires.  In FL it was a firebreak and romex that I had to go thru to add one can / light switch in one hallway done up in the attic but a real PITA.
 
The original outside placement of the ONT was planned and tapping in to the middle of the master bedroom and I stopped it and ran new romex from the master bedroom to one of two walk in closets which worked fine but again with the romex was a PITA to do.

 

[Ira]

If you have attic above every wall, it will be relatively easy to retrofit any cables needed, if you don't use spray foam insulation.

It will be, except that the roof line is all hip roofs so if I want to add a cable to an exterior wall later (or an interior wall location near an exterior wall) there's very little attic headroom to work with. Those locations would be good to have some type of conduit in place for later use, having the conduit run up the wall then maybe 10' away from the exterior wall to get to a location with some attic headroom.

 

[pete_c]

Here a few time have run LV / HV on outside walls and did baby steps and multi used the autonomous chases.  IE: kitchen flush mounted LCD TV chase also provided inside speaker connectivity, HD and IP cam and deck speaker which was the same in the laundry room outside wall (which was brick) LCD TV setup chase with cam facing a rear house exterior door.  It was difficult to run the HV conduit but also done while patching and painting the rooms.  IE: laundry room was a total revamp with new shelves, new floor (tile and underlayment) and automation stuff.  Very low on the WAF as I was not timely enough and had moved the washer and dryer outside of the room to do this.  2nd floor outside walls near the roof lines just did all of the LV work in the room cutting drywall mini access holes drilling in to the top of the stud and fishing wire to the ceiling via another small access hole then patching and painting and easier than crawling in the attic to the edges of the roofline.  Recall doing one metal conduit fitting a 90° section via a cut in the drywall access panel (just enough room for my hands).  A whiz- bang master LV/HV electrical GC would know this anyways.
 
I have seen LV run in returns / supplies used as chases which is really mickey mouse.  2nd home in the 80's here did utilize a huge brick stack in the middle of the house with insulated ventilation pipes inside for running LV electrical.  Here the HVAC was zoned with 2nd floor zone over the first zone installed in the basement.  The HVAC was in a closet and I built an access panel behind it from another closet in one of the bedrooms. (I used it for water too for the humidifier on the second floor).

 

[wkearney99]

I know it won't be a popular opinion but unless you're looking at a difficult situation most conduit will be a complete waste of time and money.  
 
Sure it's helpful in a concrete floor, or inside of exterior walls that are going to be spray foamed or across an area that has conflicting structural members (beams, joists).  
 
But, honestly, if you PLAN your use of the space effectively and run a few cables strategically there's really not much point to doing that AND adding conduit. 
 
Know this, it's never a good plan to think about adding anything to a conduit later.  Anything you pull through is likely to snag or otherwise stress wires that are already in the conduit.  Unless it's a 4" pipe with 3 cables in it there's just never going to be enough room.  I know, some folks will claim to have had success with this, and bravo for their luck.  But more often than not you WILL have problems.  
 
Then let's talk about smurf tube.  Unless you're running 1" or larger it's a hassle trying to get things through the corrugations.  That and 1" tube is a hassle to mate to single gang boxes, even with a 2 gang it's unwieldy trying to get the conduit wrestled into place without twisting the eff' out of plastic boxes, and then making decent PVC glue joints.   Unless it's a difficult location to reach, traditional flexible auger bits, wire fish tape and/or fiberglass poles will work just as well.  It'll definitely be less expensive.
 
The convenience of the conduit is you can pull everything out and run a new set through later without opening the walls.  That's it.  
 
Plan.  Know the inside of the wall structures.  Take pictures.  Put wire in strategically.  Refer to your pictures later if/when "something else" comes along.

 

[Ira]

Planning may be fine for what may come over the next five years, but much beyond that is guessing. When I built the house 25 years ago, I ran lots of RG59 for television. At that time, few people were talking about DirecTV and their (at one point) need for two coax cables at each location. Ten years ago, I doubt many people were thinking about cables that a homeowner will find very difficult to terminate (HDMI).
 
My limited experiences pulling thru smurf were not that bad, especially since the tube was at most 15' long, had at most a single large radius 90, and had a pull string in it to begin with. I have done this several times in tubes that were added after the house was built. And I always pull another pull string with the cable for the next cable that needs to be added.
 
I will discuss with my electrician next week, but I'm guessing the cost to run the last 10' to 15' of some cables in a few strategically placed tubes will be minimal compared to the overall cost.