As part of some planned remodeling, I have the need to run new cables upstairs, and potentially the opportunity to do it without fishing. On the second floor, I’ll be opening up the walls in the bathroom, exposing the plumbing stack. On the first floor, the stack is hidden behind a cloakroom behind the kitchen, so it appears feasible to open the wall there and leave an access panel afterwards. So the plan (desire) is to run wires up the plumbing stack:
Volt Amps Num
240V 15A 1-2
240V 20A 0-1
120V 15A 3+
120V 20A 1-2
One wire will be GFI. The more 120V/15A wires I run up, the more opportunities for installing AFCI eventually.
I’d like to run these wires in conduit, preferably grounded EMT.
I also want to run say 3/4″ conduit (PVC or grounded metal?) for computer/home entertainment cables. Eventually I guess this will be fiber for a home ATM network :-), right now just thinking Ethernet CAT5e or CAT6.
So the question is: What is code on running this soup of cables together? Minimum distances for safe combinations? Any mitigation from grounded EMT? Besides code, what combinations do people think themselves are preferable?
FWIW I am HO, some cables are for work I will be doing myself, some for others who will run cables outside if I don’t provide an alternative, and that raceway outside looks like garbage.
Thanks for opinions and advice…
Replies
Don't run any wiring up the existing plumbing stack. A major violation of common sense and code. If the stack is not used capping any stubs and cutting it out of the way, one sections at a time, will give you room to pull in your electrical run. Use this space you created to pull in a cable, four wire sized for the load, to power a sub-panel upstairs. This would be smarter than running a bunch of individual circuits.
If the stack is being used think about any walls that line up between the first and second floor. Closets are ideal because access panels can be cut into the interiors allowing access to the top and bottom plates for drilling. Once you have a path installing conduit, if everything lines up, or pulling in cables is relatively easy.
Definitely go with a sub-panel. Much easier to deal with a single large cable or a few large conductors in conduit than a mess of small wires. A sub-panel also gives you more options and will greatly simplify any upgrades undertaken in the future.
While a 60A sub would work I would consider going with a 100A panel as this, once in, gives you enough overhead to cover any future expansion without strain or having to repull the feed. A lot depends on the situation your present panel is in. Adding the sub would be a good time to update a marginal main panel. Of course, and this is as true of electrical work as pulling a thread on a sweater, replacing the main panel would be the best possible time to upgrade a questionable meter socket and riser.
While we are at it we could replace that unsightly service drop with an underground lateral. Of course this is going to make the hanging telephone and cable lines look shabby so we might as well put those underground as well.
While we are digging down the drive it would be a good time to run some driveway and security lighting. At the very least a lighted gate, brick arches always look nice with ivy growing up them, and a couple of reproduction coach lanterns, not to mention the intercom and doorbell.
Of course the intercom would be so much better if you could answer it from upstairs and if your pulling in low voltage the whole house sound system, and a security system to protect your investment, is logical.
We can get started next week. Or as soon as the third mortgage and credit check comes through. Before this is all over my guys will feel like, if you have a daughter they may actually end up being, family.
I assume that, by "plumbing stack", you really mean the plumbing raceway (vs running wires inside the drain/vent pipe). If so, then my impression is that this is legit, so long as you maintain fireblocks (especially going into the attic, though one at each level is better) and observe required distances.
I personally don't know of any requirements to separate AC and low-voltage wiring other than they must be in separate conduits (though I'm not a NEC "lawyer"). However, it's always wise to keep low voltage wiring 6-12 inches away from AC wiring to avoid hum/noise pickup.
Yes, I meant the raceway, I wasn't planning on pulling the conduit out through the toilet....though this makes me wonder:
http://www.taunton.com/finehomebuilding/pages/h00042_p2.asp
(scroll down to bottom of first page)
Anyway reading my post made me realize that yeah feeder panel is way to go.... Wish I had thought of that a month ago, before I got those automated security gates and intercom etc... A 12-place 100A feeder looks about right, 2 240V circuits, 2 120V for AC, 2 120V for bathroom, 1 AFCI per bedroom and a circuit for a computer...all done! All right, better price out the 20-place panels...yikes....
Then I have to run 100A wire about 22.5' horizontally and then up. Looks like code says 2% drop in 6AWG 100A 240V over 55', we are pushing it... Should I try to get by with say 60A in 100A panel? I read somewhere that the average house with electric range top and dryer etc draws max 40A at a time, don't know if that includes CAC.... Don't vacuum or run the hair dryer while AC is running?
Now here's my remaining worry: if following plumbing raceway (correcting my terminology), this will go up by the back of the kitchen, to the left of the refrigerator, what is the EMF danger to personnel in the kitchen? How much will grounded EMT conduit protect people? I know, the advice is to run the conduit outside the house....This seems to be about where we came in....
BTW Happy Bloomsday to everyone....
Edited 6/15/2004 10:14 pm ET by Taylor
I do wonder if it's legal to have a breaker panel in an attic. A breaker panel must be "readily accessible", and most attics fall a bit short of that standard. Plus the heat in an attic may be sufficient to derate the breakers.
In any event, there is no EMF hazard due to the wiring. If the wires in a circuit are close together (within an inch or so) , and especially if they are enclosed in steel conduit, the radiated EMF is negligible. You get more from your toaster.
It's a walk-up attic and the natural position for the panel is right at the top of the stairs. Of course I've been thinking about how to air-seal and insulate that attic stairs....
The heat in the attic during summer is something I'm concerned about....
Edited 6/16/2004 4:18 am ET by Taylor
> it's always wise to keep low voltage wiring 6-12
> inches away from AC wiring to avoid hum/noise pickup.
Including the CAT family I guess, right, that's a bit of a pain....hmm...hmm....Does anyone have experience running a home Ethernet network over fiber? Just asking...I don't even know if this is possible, need to adapt at the connections...splicing could be a real problem....but get rid of those thick copper cables....
I am assuming all those home automation and entertainment cables are a passing fad and eventually everything will run IP (shudder) or ATM over fiber...
I don't think you need to worry much about cross talk from AC circuits to LAN cables. The frequencies are wildly disproportionate. It's like worrying about the effect of the orbit of Venus on your day to day affairs.
Audio cables, yes. Music often has significant energy in the 60 Hz range, so 60 Hz noise is a problem. LAN traffic has no information at 60 Hz.
The problem with AC near Cat5 is that if the hum level gets high enough it overloads the inputs of the ethernet receivers, so they start getting errors.
That said, the hum level has to get pretty high for this to happen, and Cat5, given the way it's twisted, is very good at avoiding hum pickup. I've experimented a few times, using transformers, etc, to try to force errors in Cat5 ethernet and have never been successful.
So the real rule is "avoid if reasonable" vs "avoid at all costs" having Cat5 run close & parallel to AC wires. (Of course, the rule about separate conduits isn't optional.)
One other thing is that Cat5 should be kept away from any low-level audio cables to avoid getting computer noise into the audio. And Cat5 probably should be kept away from speaker cable to avoid audio pickup by the Cat5. Also, potential interference from speaker cable will be greatly reduced if the speaker cable is twisted vs zip cord.
It's certainly possible to run a home LAN (or at least a backbone connection between hubs) with fiber, but it still costs an arm.
"It's certainly possible to run a home LAN (or at least a backbone connection between hubs) with fiber, but it still costs an arm."
No the prices have gone way done. It only cost 3 fingers and a toe now.
Prices are so low that when I signed up for DSL thay gave me a wireless hub. So all those cat5e homerun cables that I painfully routed during our remodel may already be obsolete.
At risk of triggering another jihad from the structured wiring afficianados, I'm going to recommend that you just go with cat5e (copper). It's not that thick, and the economics make much more sense for the home. Right now, home broadband typically does about 3 Mbits/sec, and a properly run and terminated 5e will do 1000. The huge installed base of CAT continues to drive it to the lowest cost and greatest availability for available hardware. If you really want upgradeability down the road, pull smurf tube or similar.
Pete
Yeah, I wasn't very serious about fiber, we're not there yet....but any kind of network cabling one puts in now will probably look like a wire and 2 cans in a few years....I'm planning CAT5e or CAT6 through conduit...
For the low-voltage stuff, I'd suggest something bigger than 3/4". I ran two 1 1/2" conduit from my stereo closet to my attic, and frankly I wish that I'd gone bigger. If you end up wanting to put coax cable in it, 3/4" can only hold one run (okay, perhaps 3, but I wouldn't want to pull them).
Twisted pair is pretty good at getting rejecting interference, so I wouldn't worry too much about the location (though I wouldn't want it right next to an AC line, if it's a few inches away I think you'll be fine).
Other have mentioned wireless, which is great, but is limited in bandwidth. Even the best wireless only gives you around 50MBit with a full signal, and other devices (cordless phone, microwave) can interfere.
If you can have megabit ethernet, it's a whole lot faster than wireless right now.
Does your ISP give you service that is faster than 50 MBPS? If so, then you are blazing!
Jon Blakemore
I spoke to my sparky about running 4AWG through grounded EMT to minimize EMF. This is an idea I got off this board. He says I'm better off running 4AWG Romex, the twisted cables will minimize interference and EMT will only make things worse. And running Romex through EMT violates code. Comments?
Residential wireless: Just Say No.
Edited 6/17/2004 1:15 am ET by Taylor
My understanding is that romex is ok in conduit, you do have to derate it to compensate for the additional heat build up.
Seems to be a bit controversial running romex in pipe. Why not single insulated (a more standard wiring method)?
My concern is not exposing my family to unacceptable levels of EMF, while running cable to feeder panel through the house.
I got the idea, of putting the wire in EMT, from an earlier thread in Breaktime:
"it is not the thickness of the metal that matters, it is it's conductance and it's resistance to being affected by magnetism.
"In military secure communications, where they take electromagnetic interference real seriously, a thin screen of copper is used wherever an aluminum equipment case is not enough. Hi conductance and non magnetic.
"If you're gonna use metalic sheathing for EMR in a residence, well grounded EMT is the cost effective way to go."
Sparky says I'm better off twisting Romex.
I'm wondering if I can combine the ideas (I'm a belt-and-suspenders kind of guy)? Running grounded Romex in grounded EMT. I guess the problem is heat buildup with Romex in conduit, so I'd have to go lower than 4AWG, yikes.
There is another argument for conduit: reduced likelihood of mortality next time I or some subsequent owner hangs a picture.
Another previous thread says Chapter 9 Tables Note 9 allows suitably sized Romex in conduit. Er can anyone tell me what that says? Hopefully local code has kept its hands off this and Sparky is not aware of this note.
"My concern is not exposing my family to unacceptable levels of EMF, while running cable to feeder panel through the house."
What is an UNACCEPTABLE LEVEL? What is your current level? And how are you measuring it?
"I'm a belt-and-suspenders kind of guy"
Then pull your electrical meter and get rid of all of the batteries.
So which would you choose? Twisted Romex or grounded EMT? How much reduction in EMF if I try to combine the two?
Thanks for your response.
Edit: To answer your question: WHO recommends 100 milliGauss as acceptable level. My impression, from speaking to people who do research in the area, is that they're guessing as to what's acceptable.
Edited 6/17/2004 12:50 pm ET by Taylor
Once again, you'll get more EMF from your toaster than from that cable. I'm serious.
Ok fair enough thanks. Looking for a reality check.
Some interesting numbers I came across:
- vacuum cleaner 230-1300 mG
- microwave 100-500 mG
- blender 50-220 mG
- washing machine 8-200 mG
- television 4-100 mG
- computer 4-20 mG
and the winner is
- hair dryer, from 60 to as high as 20000 mG
CAT6 is the current standard, it's compatible and interchangeable with CAT5e and presumeably with follow-on standards for some time to come; but, you want to buy what's current. Our current trend is to buy pre-made (off-the-shelf for short runs, custom-ordered for longer) with sealed connectors and then use back-to-back (F-to-F) connectors through the wall-plates. Wall-plate connectors (female) can be specified for the custom-length cables, of course, to save a conection, but that means multiple types of termination. Some DIY'ers just run and extra 10' of cable to every location and just run that out through a wall-plate that's merely and portal (aka: hole in the wall).
Optical may sound enticing, but boy does it cost big-time.
Phill Giles
The Unionville Woodwright
Unionville, Ontario
Just a thought I had. If you are pulling wires up the plumbing stack raceway, also pull a piece of heavy string or thin rope twice the length of the pull. Makes it much easier to pull additional cables up that pathway in the future.
If you are using conduit, you can do the same, but the conduit will have to be pretty large and pretty unoccupied to pull additional lines.