Approved methods for running electrical wire

[Anthony Whitesell]

I see that lots of people looked at my other thread, but I didn't get any reponses. That's cool, as I figured out this morning the cost of the running 6/3 between the main and sub panel is the same as running ten (10) 12-2 circuits. As the sub will only have 5 or 6 (definately less than 10), I will have a 100A panel for sale next summer. I'll just have to forgo the ability to disconnect the shop with one switch.

On that note, I'm looking for the NEC approved ways of running electrical wire, specifically the approved methods for supporting wire in horizontal runs. I would really love not to have to staple 5 or 6 wires every 16 inches all running in the same direction. I'm hoping there's some type of approved method for "cable traying" wires in a residence.

[Dan Hintz]

NEC code (which is the usual adoption for most locales) is a support every 4' (every 3 studs 16" OC), and stapled near boxes within 8" (I'm not positive on that measurement, it may be a couple of inches more, and I don't have my little red book near me).

[Anthony Whitesell]

I'm not as worried about near the few boxes, as I am the run across the basement.

"support every 4' (every 3 studs 16" OC)" doesn't say stapled or nailed. For example purposes (as I would use something smaller and better but along the same lines), could you use those J-shaped pipe hanger brackets every 4'? (Although I personally would go every 16" to minimize droop and make the install a little nicer.)

[Dan Hintz]

I use these:
http://www.summitsource.com/images/products/CACMC1.jpg
The ribbed/latched portion hangs off the back of the stud, and I can swap wires/remove them as needed. These are intended to act as multi-wire supports up the length of a stud while keep to NECs 1.5"-off-of-face rule (which cannot be held to with more than about two wires), but I repurposed them.

EDIT: When running 12 Gauge wire (pretty much everything I run is at least that thick), 4' OC doesn't show a lot of droop (a few inches?). The idea is to support the wires over long distances to prevent them from dragging each other down. The staples at boxes are to prevent people yanking the wires during socket changes.

[Charlie Velasquez]

Anthony,
I would rethink your plan. It may be cheaper to run multiple 12 ga. circuits, but it will not give you the flexibility of your original plan.
I am not an electrician, so please, if I am way off I am hoping someone will chime in and fix my numbers but...
from your other post it sounds like you will be going 75 feet to get to the area, plus whatever distance the circuit is... let's say an additional 15 feet, so, 90 feet total. You will probably have some bigger tools eventually...3.5hp router, something that will use almost all 20 amps. With individual circuits that load will travel the entire distance on 12 ga. wire. You will get a voltage drop of maybe 6%. I don't know if this is significant to the performance of the tool, but I know I cringe when I have to use long extension cords, even if it's 12 ga.
With a sub, you may have that 20 amp load, plus 2 amps to your cordless chargers, plus 8 amps for something else, plus 10 amps to a small dust collector on a 6ga. wire. Now your down to about a 2% drop plus a <1% drop on the 15 foot branch circuit.

Additionally you may want to run 220 at some point. Very simple if you run the sub-panel.
My dad used to tell me, "Pay now and cry once, or pay later and cry every time."
If the cost is even close (within 2-3 hundred) I would run the sub.

PS. Look around, I was able to pick up some 6/3 at our local Habitat for Humanity recycling store dirt cheap. . . . . Although, I would prefer to go 4/3. Bigger IS better.

[Anthony Whitesell]

20A 220V or 20A 110V uses the same wire. According to the 3% rule, 12ga wire is good for only 25' at 20A. If I don't install a sub, I won't be running 75' closer to 50' which should be 10ga wire at a full 20amps which should also blow the 20A breaker. So based on the table 50' 12ga wire will adequately provide 15-20amps. Thank you for motiviating me to check that all through.

[Rollie Meyers]

I'm not as worried about near the few boxes, as I am the run across the basement.

"support every 4' (every 3 studs 16" OC)" doesn't say stapled or nailed. For example purposes (as I would use something smaller and better but along the same lines), could you use those J-shaped pipe hanger brackets every 4'? (Although I personally would go every 16" to minimize droop and make the install a little nicer.)


That would be bundling, which would open up derating issues, in a residential situation in the real world it is not a problem but the NEC thinks otherwise & it has more clout. :D