CAT 6 cable in the same conduit as THWN wiring?

[Shujinko]

I have project where we have light poles with security cameras at the top of pole. Conduit was roughed-in the light pole for power for lighting (THWN), but not for CAT 6 for the security camera. Is there any scenario/exemption in the code or a cabling product that would allow for CAT6 cable to be installed in the same conduit as power wiring (THWN)? The circuit for the pole lighting is 240V/1PH in some cases and 277V/1PH in other cases. I appreciate the help in advance.

 

[LarryFine]

Sleeved Cat6 in same conduit as power ?

Hello, I'm working under NEC 2020. I have an existing underground 2.5" SCH40 PVC conduit with 240V power inside it to a remote building. It's filled at 17%. I'm trying to run direct bury Ethernet Cat6 through this conduit but it seems like NEC does not allow this under n 805.133(A)(1)(c)...

forums.mikeholt.com

 

[don_resqcapt19]

Your only options are in 725.136(I).

 

[hbiss]

Conduit was roughed-in the light pole for power for lighting (THWN), but not for CAT 6 for the security camera.

Actually, if I'm understanding you correctly that's good. If the power conductors are in conduit inside the light pole you can run your CAT 6 up the light pole along side of the conduit.

What you don't say is how you are getting the CAT 6 to the light pole. Hopefully independently of how the power is run.

-Hal

 

[Jraef]

All conductors in the same raceway must be rated for the highest voltage preset. Most basic CAT 6 cable is going to have 300V insulation. If your THWN is only carrying 277V or less you are good. If not, I know you can get CAT 5 that is rated fir 600V.

 

[tom baker]

All conductors in the same raceway must be rated for the highest voltage preset. Most basic CAT 6 cable is going to have 300V insulation. If your THWN is only carrying 277V or less you are good. If not, I know you can get CAT 5 that is rated fir 600V.

Yes that is what 300.3 C states, but please see the IN at end of section

 

[hbiss]

If it's only the light pole he is concerned about and the power conductors are run in conduit up through the pole to the top, he certainly can drop an ordinary CAT 6 down through the pole and be in compliance. The power and LV is separated by the conduit.

However I suspect there is another side of this story we aren't hearing, that being how the CAT 6 and power is run in the ground to the pole.

-Hal

 

[don_resqcapt19]

All conductors in the same raceway must be rated for the highest voltage preset. Most basic CAT 6 cable is going to have 300V insulation. If your THWN is only carrying 277V or less you are good. If not, I know you can get CAT 5 that is rated fir 600V.

This is a case where the Chapter 7 rule found in 725.136 modifies the Chapter 3 rule in 300.3(C), per 90.3 and the very reason for the Informational Note following 300.3(C)....a note that very few ever read.

 

[VirutalElectrician]

See 800.133.

https://www.mikeholt.com/instructor2/img/product/pdf/11LE-968-sample.pdf

300.3(C) seems to say yes, 800.133(d) seems to say no, unless there's a barrier.

 

[Another C10]

Unless its changed, the only low voltage or signal conductors allowed in with a 120v + system is, in many cases the control wiring specifically for the higher voltage involved. Being that the noise of a lighting system is probably minimal compared to a motor circuit and that the cat6 is probably shielded it may be ok but personally I wouldn't do it, nor would any inspectors I've come across accept it, although really what damage could it do other than having a fuzzy camera image.

 

[Another C10]

one possibility though, run a 1/2" seal tight for the cat 6 within the 2-1/2" which would isolate the two systems.. granted you'd be at the mercy of the inspector.

 

[GoldDigger]

one possibility though, run a 1/2" seal tight for the cat 6 within the 2-1/2" which would isolate the two systems.. granted you'd be at the mercy of the inspector.

If proper separation is made at the exit ends of the seal tight, I see this as fully code compliant, under the same rationale that luminaire cable is allowed. Even though the two circuits in this case are not clearly functionally related.

 

[hbiss]

one possibility though, run a 1/2" seal tight for the cat 6 within the 2-1/2" which would isolate the two systems.. granted you'd be at the mercy of the inspector.

Some people don't understand.

• You can run the power conductors in sealtight within the light pole and then run your CAT 6 outside of the sealtight down the light pole.
• You can run your CAT 6 in sealtight and have the open power conductors running down the light pole.

It looks like there is already conduit for the power conductors, so dropping a CAT 6 down next to it is allowed.

If proper separation is made at the exit ends of the seal tight, I see this as fully code compliant,

That's another situation that needs to be addressed- how to maintain separation between the power conductors where the CAT 6 enters and exits the pole and whatever enclosure is on the other end. That may not be a problem at the light pole assuming the camera is below the light fixture. With the CAT 6 run inside the pole, simply poke it out through a hole.

We are still waiting to hear how the poles are fed underground.

-Hal

 

[DrSparks]

Unless its changed, the only low voltage or signal conductors allowed in with a 120v + system is, in many cases the control wiring specifically for the higher voltage involved. Being that the noise of a lighting system is probably minimal compared to a motor circuit and that the cat6 is probably shielded it may be ok but personally I wouldn't do it, nor would any inspectors I've come across accept it, although really what damage could it do other than having a fuzzy camera image.

It really depends on the signalling technology.

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[DrSparks]

As long as the voltage rating is maintained, end to end, and the cable is rated for the maximum voltage present at any point, no separation is needed.

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[petersonra]

As long as the voltage rating is maintained, end to end, and the cable is rated for the maximum voltage present at any point, no separation is needed.

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Ethernet cables are class 2 circuits. How do you get around the requirements of article 725?

 

[tom baker]

300 3 C somehow is a rule every electrician knows but they read no further

 

[tom baker]

As long as the voltage rating is maintained, end to end, and the cable is rated for the maximum voltage present at any point, no separation is needed.

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Please review section 90.3. When I taught electrical classes I would say it is the most important rule in the NEC

 

[ggunn]

...although really what damage could it do other than having a fuzzy camera image.

If the video is digital it won't be fuzzy, it will be pixelated, blocky, or stop-start if it is interfered with.

 

[Another C10]

If the video is digital it won't be fuzzy, it will be

Ya got to appreciate the specifics of an electricians mind.