Subscriber Discussion

Are Cables Inside Poles Against Code?

U
Undisclosed #1
Apr 12, 2017

Question of the day: I have a number of IP POE cameras to be mounted on existing light poles. Closest is 350' and the furthest is 450'. My electrical guy tells me he will not run any cable (presumably copper) inside the pole due to Code issues. It's an easy trench and an easy microwave shot (multi-point to point w good line of sight). What would you do? If you wanted to run copper cable, what cable would you use?

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Brian Rhodes
Apr 12, 2017
IPVMU Certified

I'd push back on the electrician to cite the code in question.

I think he's either misunderstanding the citation or misapplying it.

Running cables inside of poles is pretty common for cameras.

(1)
UI
Undisclosed Integrator #2
Apr 13, 2017

The National Electric Code (NFPA 70) prohibits the mixing of conductors with different electrical insulation ratings within the same raceway, in this case the light pole.  Therefore, if the THHN cable is rated to 600v the Cat5 jacket would also be required to insulate at 600v (it exists).  That being said Brian is correct, it happens all the time. 

(1)
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Brian Rhodes
Apr 13, 2017
IPVMU Certified

Moreover, there are accepted methods of separating inside cavities of poles so they are not 'the same'.  See: For Light Pole Mounted Camera, Can Camera Cable Run Through Light Pole With Light Power?

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Jon Dillabaugh
Apr 14, 2017
Pro Focus LLC

If the line voltage wire is in conduit, doesn't that suffice as well? You could run some LFMC down the pole to run your Cat wire too, if there's room for it. 

U
Undisclosed #1
Apr 14, 2017

This is an existing pole, so running LFMC may be difficult. 

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Jon Dillabaugh
Apr 14, 2017
Pro Focus LLC

How about simple 3/8 flex then? If all you have is a single Cat run, that should suffice. If you can't pull 3/8 flex through the pole, I'm unsure if it's safe to run Cat cable in there anyways. The amount of interference you will get from running parallel to the line voltage wire will be very damaging. At that point, you will need to change to fiber. 

MB
Mark Bottomley
Apr 18, 2017

I would be wary of the distance more than anything - IP is supposedly limited to 328' and although you may get connectivity further than that, but it may be unreliable. I know IPVM did an article on over-spec connectivity a while ago.

https://ipvm.com/reports/test-long-ethernet

(1)
TB
Tim Ballman
Apr 18, 2017

liquid tight application right up the pole. separate comm from electrical by 2 different lines. no code violation here on that

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Timothy Howell
Apr 18, 2017
IPVMU Certified

I agree with all of the discussion above, I get on projects once in awhile where we have lots of "code book experts".  Definitely ask the electrician to cite the code he is referring to and the vast majority of the time the issue goes away.  The comment above about jacket insulation ratings being the same is right on, if for example someone is running CAT6 in a motor control center with 480VAC (to connect with a power monitor) the jacket rating must be 600V UNLESS the MCC has a low voltage compartment where the cable terminates.  Both configurations are common.  One other question to ask is if you are working in an unknown jurisdiction or one that you have not worked in previously its good to know what the AHJ thinks about all that.  Different jurisdictions across the US vary the code implementations and those portions of the code they will enforce.  Here in Austin, the AHJ has added several addendum's that really go beyond the code.

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