Power and phone lines for the shop - meeting the NEC

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If you use twisted pair for your phone line it won't be bothered by the power. That is also true of CAT5 and LANs. The design on a NIC rejects virtually all "common mode" noise. If telephone lines were bothered by 60hz they certainly wouldn't be putting it on poles next to fat transformers and 13kv cables. The secret is twisted pair tho. Straight through (red,green,yellow,black) will pick up everything from adjacent phone line crosstalk to your local radio station.
As for the EGC (ground) the other posters are on point, #10 minimum and you want #8 min to a ground rod. Anything smaller than #4 requires physical protection.
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False. Ground wire size depends on the rating of the overcurrent protection device, and is specified by Table 290-95. [NEC, Article 290-95]

False. This is _explicitly_prohibited_ by the NEC: "Communications conductors shall not be placed in any raceway, compartment, junction box, or similar fitting with conductors of electric light or power circuits..." [NEC, Article 800-52(a)(2)c.1]
-- Regards, Doug Miller (alphageek-at-milmac-dot-com)
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The only way you can run LV and line voltage in the same conduit is if one of them is in another raceway inside that big one (usually the LV). This is pretty common when you have duct banks between buildings but not that practical for residential or anything you are building to a spec. The duct has to be pretty big to accomodate a raceway plus whatever conductors you run.
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wrote:

Actually, I just read it in the NEC a few days ago and now can't find where it was stated. When I find it (and my mind) I'll attempt to clarify.

Yes, you are right! I was thinking of running different voltages in the same conduit. My apologies.

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Doug Miller wrote:

Thanks Doug.
I thought I asked the inspector if it was permissible, I thought he said yes with 600 volt insulation.
I guess I should ask again.
I guess all those lighting conductors I ran in the conduit with communications conductors are now going to be low voltage operating relays.
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The current NEC does not permit it, and I think that has been true for a long time, as long as I can remember, but *local* code does not always follow the NEC. And local inspectors may interpret the code differently than you might think. It almost never causes a problem to use a safer practice than the local inspector requires, but I would never try to convince him/her to let me squeak by on something.

I really hope you mean this.
Bill Ranck Blacksburg, Va.
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You must have a separate, full sized neutral, and a ground. The neutral and ground must have separate busses, and the neutral buss must be separate and insulated from the case of the breaker housing. One of the busses is probably already insulated, and has to be grounded, if need be, with a separate thingies.
--
Jim in NC



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Got it. I bought one of the GE consumer main lug boxes and purchased a separate ground bus that bolts straight to the case.
Whew! Its a good thing my labor is free. I started down this quest because just adding branch breakers to my existing panel was so darned expensive (no-longer manufactured Federal Pacific). It was cheaper to add one big breaker in it to feed the subpanel. I like the idea of paying $8 for a dual 20 amp breaker instead of $48!
Bob
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