S.O. Cords/industrial circuitry

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rjmockster

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I just had a quick question to ask about running S.O. Cords through conduit. I know that you're not supposed to take up more than 40% of the crossface section in your EMT with wiring, but, does this include S.O. cord even though this type of cord just has more insulation around it than a regular wire bundle? We don't typically just pull S.O. cord through conduit but, sometimes just a short run does'nt seem like a bad idea for maybe the sake of avoiding any unnecessary splicing or more junction boxes.
 
Re: S.O. Cords/industrial circuitry

I have to disagree with Hal. In industrial plants, SO and and other types of cord are used for sensors and other machine mounted devices all the time. It is strapped to the machinery, ran through Unistrut and fed through conduit where physical protection is required. NFPA 70 (the NEC) does not apply to these machinery installations but to buildings. I would be interested to see the article in NFPA 79 that prohibits the method you (and I belive I) are speaking of.
 
Re: S.O. Cords/industrial circuitry

Well as Rich mentioned SO cords are everywhere in most industrial plants. This one in particular is wired to a 110 vac limit switch through I would say about an 8 foot stick of conduit. I guess according to everyones feedback, it's probably best to go ahead and add a junction box and run the SO from there. Thanks for your feedback everybody, I greatly appreciate it!
 
Re: S.O. Cords/industrial circuitry

Not so quick! As has been pointed out, if the SO cord is on and part of the machinery wiring then MAYBE. But if the SO cord is part of the building wiring (meaning that it is run from a point in or on the building) then it is subject to the NEC and is it is not allowed in conduit or attached to surfaces.

Just because SO cords are "everywhere" doesn't mean that its use is allowed. Where was it that I read about a whole factory full of machinery being supplied by miles of SO cord fed from 480 volt panels? :eek:

Many times SO cord is used as a cheap, easy way out by in- plant maintenance people who don't know any better and management who don't want to spend the money or take the time to do the job right.

Edit: Oops, sorry rjmockster, I just read your profile- no reflection on you!

-Hal

[ June 29, 2004, 04:03 PM: Message edited by: hbiss ]
 
Re: S.O. Cords/industrial circuitry

Yes, Hal is 100% correct with his take on the over usage of SO cords in industrial circuitry. I would estimate that about 40% of my conduit running experience comes from people (I'll put this in nice terms) who felt that they just did'nt have the time to bend and hang a little bit of pipe, pull a few wires, and just basically do the job right the first time. I used to get frustrated when I ran on to projects like that, but these days I just take those situations as more much needed experience for me.
 
Re: S.O. Cords/industrial circuitry

Per 100-I, a raceway is "...an enclosed channel...".

IMO, if the conduit is not terminated at both ends then it is not a raceway and it may be used to provide mechanical protection to flexible cords. In fact exceptions to 300.10 and 300.12 recognize this practice, however they do not define "short sections".

In regards to wiring integral equipment to/on machines Art 300 is not applicable (300.1(B)). Supply conductors to the industrial machine are covered per 670.1
 
Re: S.O. Cords/industrial circuitry

The NEC does not specifically say that you cannot run SO cable through conduit. You cannot use it in conduit, because of the listing. SO cable is UL listed and tested for certain apps and usages.
Running it in conduit, you are using it outside what is was listed for. If there is a real good reason you run part of it through conduit or only a short section and you need the flexibility on one/both ends, an inspector could let it go.
However, bottom line you cannot do it because you are using a UL listed device outside its listing, which is a nono. :roll:
 
Re: S.O. Cords/industrial circuitry

Originally posted by klaus:
The NEC does not specifically say that you cannot run SO cable through conduit.
Click to expand...
What about this?
400.8 Uses Not Permitted.
Unless specifically permitted in 400.7, flexible cords and cables shall not be used for the following:
(6) Where installed in raceways, except as otherwise permitted in this Code
Click to expand...
I would disagree with your statement.
 
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