Enclosure Listing a Internal Wiring

[jsinclair]

I have a dilemma here that I need some help with. I am currently installing new telecommunications equipment that is not listed. The enclosure is roughly 3'x3'x4', outdoor, with a large access door on the front and the rear. The cabinet houses an AC power panel (100A, 240v, 8 space), (3) 125A DC rectifiers, (4) batteries, a DC distribution panel, and some small communication devices. There are also RF cables, CAT5E, DC power, and 25 pair alarm cables running through the same space.

The problem is with the installation of the AC wiring to the panel contained within in the cabinet. To wire the panel, the wire must enter through the side of the enclosure then "free air" it for a few inches up to a few feet until it reaches the AC panel. I am fighting to require it be in conduit or some other "barrier" all the way to the electrical panel. Here's why:

820.52(A)1(5)b - States that coaxial cables shall not be placed in any enclosure with conductors of electric light, power, ......

300.3(C)1 - States that all conductors that occupy the same enclosure must have an insulation rating of at least equal to the largest voltage applied to any any conductor in the enclosure.

I have RF coaxial cables running in the same enclosure with CAT5E, 25 conductor alarm cable, DC power cable, and AC power cables. Those two code articles do not seem to permit this combination without the AC power being seperated from everything else.

I have pictures I am going to try and get inserted here. How is that done again?

[ September 22, 2004, 05:44 PM: Message edited by: jsinclair ]

 

[gndrod]

Re: Enclosure Listing a Internal Wiring

Is the power panel listed? Without seeing what you have at this time, isolating the power input and outputs is a must from the ancillary class II and coax wiring. Possibly locating a ground plane partition for a channeled raceway within the overall custom cabinet can qualify as an acceptable raceway separation for AC power cable and power adapter-conversion. If you look at some of the structured media enclosure setups, notice how the AC input j-box/receptacle partitioning is accomplished. LEVITON, HUBBELL, and ON Q systems are all consistent in module design compatible with NEC separation conditions.
rbj

 

[hbiss]

Re: Enclosure Listing a Internal Wiring

820.52(A)(1)(5)(b) and 300.3(C)(1) relate to individual conductors within a J or device box. I think what you have would be described as a shelter. This would be no different than a closet of the same dimensions in a building. There should be no exposed class 1 conductors outside of the panel and receptacles.

I think that as long as the service cable you use terminates in the panel and you handle the branch circuits properly you are OK.

-Hal