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seaneys
11-30-2008, 06:38 PM
I'm going to put my ethernet and a/v cable in pvc conduit (extremely low voltage).

What codes apply to network wiring. I do not see anything in the NEC.

Thanks,
Steve

Speedy Petey
11-30-2008, 07:10 PM
NEC Chapter 8

beekerc
12-01-2008, 10:55 AM
FWIW,
I asked a licened electrician associate of mine the same question with regard to my basement, specifically, running rough-in wires through PVC (1-1/4" sched 40), and leaving an empty (same spec) pipe with pull strings for future expansions, proximity to A/C, HVAC and flourescent fixtures. I was told....
- keep parallel runs of ethernet, telco and co-ax a minimum of 12" apart from A/C
- keep cross-overs between lo-voltage and A/C as close to 90-degree, right angles, as possible
- do not run A/C and lo-voltage through the same holds drilled through studs
- that there were no restrictions regarding running through PVC

no mention of code requirements/restriction was made, however since SP, above, has referenced an NEC chapter, it would be good to check out.

B

jwelectric
12-01-2008, 11:23 AM
FWIW,
I asked a licened electrician associate of mine the same question with regard to my basement, specifically, running rough-in wires through PVC (1-1/4" sched 40), and leaving an empty (same spec) pipe with pull strings for future expansions, proximity to A/C, HVAC and flourescent fixtures. I was told....
- keep parallel runs of ethernet, telco and co-ax a minimum of 12" apart from A/C this is good practice but not required be the NEC
- keep cross-overs between lo-voltage and A/C as close to 90-degree, right angles, as possible again this is good practice but not required be the NEC
- do not run A/C and lo-voltage through the same holds drilled through studs again this is good practice but not required be the NEC
- that there were no restrictions regarding running through PVC see below

no mention of code requirements/restriction was made, however since SP, above, has referenced an NEC chapter, it would be good to check out.

B

ARTICLE 640 Audio Signal Processing, Amplification, and Reproduction Equipment
640.23 Conduit or Tubing.
(A) Number of Conductors. The number of conductors permitted in a single conduit or tubing shall not exceed the percentage fill specified in Table 1, Chapter 9.

800.110 Raceways for Communications Wires and Cables.
Where communications wires and cables are installed in a raceway, the raceway shall be either of a type permitted in Chapter 3 and installed in accordance with Chapter 3 or listed plenum communications raceway, listed riser communications raceway, or listed general-purpose communications raceway installed in accordance with 800.154 and installed in accordance with 362.24 through 362.56, where the requirements applicable to electrical nonmetallic tubing apply. The raceway fill tables of Chapter 3 and Chapter 9 shall not apply.

830.110 Raceways for Low- and Medium-Power Network-Powered Broadband Communications Cables.
Where low- and medium-power network-powered broadband communications cables are installed in a raceway, the raceway shall be of a type permitted in Chapter 3 and installed in accordance with Chapter 3.
Exception: Conduit fill restrictions shall not apply to low-power network-powered broadband communications cables.

beekerc
12-01-2008, 12:26 PM
Exception: Conduit fill restrictions shall not apply to low-power network-powered broadband communications cables.

so for those of us who don't speak NEC Code on a daily bases, just to clarify, there is no restriction on network or a/v co-ax cables in a pvc pipe, short of what you can physically stuff inside it. correct?

what about telco - is the 48 vDC of a POTS line considered "low voltage"? or would that fall under the "low power" exemption above?

Sorry for being dense, just trying to make sure I get it right - I'd hate to have to de-pipe all the network runs i've done so far.
Thanks

jwelectric
12-01-2008, 12:34 PM
For the audio cable there would be a requirement but for the coax cable none.

I would keep my audio and coax separate from each other so there wouldn’t be any high frequencies that bled from one to the other.
Trivial yes but worth it in the end especially if this is a high end entertainment set up.

My audio has a low hum but if I turn off the receiver it goes away. Sound and visual are in the same wire way.

frenchelectrican
12-01-2008, 12:43 PM
so for those of us who don't speak NEC Code on a daily bases, just to clarify, there is no restriction on network or a/v co-ax cables in a pvc pipe, short of what you can physically stuff inside it. correct?

the coax cable there is not much in the NEC but a good common sense will show up on this one and unforetally I did see some of the conduits really stuffed full of coax cable but for the A/V cable yes there is requirement to prevent over crowding on the conduit however what I heard most Data/com guys told me they rather keep at least 50% full so it much easier to slide and prevent some serious damage when ya pull it.

what about telco - is the 48 vDC of a POTS line considered "low voltage"? or would that fall under the "low power" exemption above?

see above comment it the same rules

Sorry for being dense, just trying to make sure I get it right - I'd hate to have to de-pipe all the network runs i've done so far.
Thanks


All my answer in Bleu colour.

Merci,Marc

beekerc
12-01-2008, 01:58 PM
keep at least 50% full so it much easier to slide and prevent some serious damage when ya pull it.

this makes excellent sense. however, on the office setups that i've done with cat5/5e/6 in the past, we usually pulled multiple wire bundles at once to get to to about 85% full, then pulled individual wires until pulling was difficult. we used wire pulling lube for the last half-dozen or so cables. in retrospect, it never occured to us that there might be an NEC code aspect to what we were doing, in part because the electricians we often worked with didn't regard us very highly since (in their words) "network voltage can't kill ya".

seaneys
12-01-2008, 07:19 PM
this makes excellent sense. however, on the office setups that i've done with cat5/5e/6 in the past, we usually pulled multiple wire bundles at once to get to to about 85% full, then pulled individual wires until pulling was difficult. we used wire pulling lube for the last half-dozen or so cables. in retrospect, it never occured to us that there might be an NEC code aspect to what we were doing, in part because the electricians we often worked with didn't regard us very highly since (in their words) "network voltage can't kill ya".

I'm struggling staying under the 360 degrees max bend requirement as I bob and weave around the EMT / metal conduit.

I'm assuming the max bend radius rule applies for low voltage runs.

Steve

beekerc
12-01-2008, 09:43 PM
I'm struggling staying under the 360 degrees max bend requirement as I bob and weave around the EMT / metal conduit.

I'm assuming the max bend radius rule applies for low voltage runs.

bend radius for network/telco does apply but not as stringently as for solid copper wire. coax does have rules, but it's not so much a safety issue, but more of an issue with video signal performance. with network/telco, you just want to avoid sharp bends, but you can maneuver them through much tighter spots and corners than you would romex.

i'm pretty sure there isn't anything in the NEC covering bend radius for low voltage/low power, but there are defnintely best practice guidelines.