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[Ethan Montgomery]

How important is it for SOOW power cords to be UL listed for passing inspection?  I suspect this varies from location to location (and inspector to inspector), so perhaps the question should be phrased as 'how common is it for this to be a requirement'?

I've been looking at 4/4 SOOW for feeding small rack-mounted distros, and 12/3 SOOW to feed stringers and powered speakers.  UL listed cables seem to be much harder to find (especially for 4/4), and are drastically more expensive (seems to be $15-18/ft for 4/4 UL, as opposed to $4-6/ft for non-UL).  Also, the cables seem to be spec'd at much larger ODs, to the point where I'm not sure if they would fit the intended connectors.  Eg, the 4/4 non-UL I've found seems to be around 1.0-1.1" OD, which would fit CS and/or 14-50 connectors just fine (as well as l14-20 and l14-30 connectors should I make some adapters), but the UL listed 4/4 SOOW I've found seems to be around 1.25", which appears too large for any of the connectors I've come across (Hubbel, P&S, etc).  I haven't looked as closely at 12/3 SOOW, which would be terminated in Powercons, but I suspect the discrepancies will be comparable.

These facts (assuming I'm reading/interpreting them correctly), combined with a lack of information that I've been able to find on PSW regarding UL listing of power cables, leads me to believe that nobody really bothers with UL listed cords.  Is that true?

I'd be operating at a rather small (to maybe 'mid' by some standards) scale, and from all the work I've done in the field over the last 10+ years, don't think I'd have any issue with inspectors whatsoever.  But for 'bigger' dogs, is this even a consideration?  Perhaps there aren't any locations in the US where this is even part of the code?

Perhaps I'm overthinking this, but then again there's no such thing as being too cautious when it comes to high voltage power.  But using SOOW of the appropriate size should have me totally covered in terms of safety, so I'm under the impression that my only concern beyond that is making inspectors happy.  True?  If, for example, using UL listed SOOW is only a requirement in union houses in NYC (which I would never be operating in), then I see no point in the extra cost/size/etc of the UL listed cables.  But, if it technically is a code requirement in many jurisdictions, I would very much like to err on the side of caution.

Sorry for the long post for a simple question, but I really want to make sure I get this right!  Thanks in advance.

[Cailen Waddell]

Someone will no doubt correct me - but I was under the impression UL ratings were for an entire assembly.  So raw cable wouldn't be UL listed but a cord with ends would. 


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[Ethan Montgomery]

Someone will no doubt correct me - but I was under the impression UL ratings were for an entire assembly.  So raw cable wouldn't be UL listed but a cord with ends would. 


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There are definitely raw/bulk cords that are UL listed.  Some manufacturers seem to even make the same cord in UL and non-UL versions.

[Dan Mortensen]

Technically, the requirement is for a "listed" cord/assembly, and while UL is the largest and most well known testing laboratory, there are other independent agencies which test list gear, putting their own mark upon it. The second largest is probably ETL and there are others yet.

When I was looking more closely at this some years ago, there were reports of specific inspectors refusing to accept any listing other than UL, but that refusal is technically illegal since it amounts to a requirement to purchase product from a specific business (UL) rather than product meeting a tested and approved standard.

Requiring UL only is not much different than a requirement that you purchase equipment from the inspector's brother's company in order to pass inspection.

And regarding assembly vs. component listing, anecdotally it seems that using all listed components to make something relatively simple like a cable with connectors on both ends is acceptable in most situations. Doing that to make a breaker panel or something more complex is not acceptable at all, and the assemblage needs to be listed, involving testing and design approval and whatever else they do to list something.

[Phil Graham]

How important is it for SOOW power cords to be UL listed for passing inspection?  I suspect this varies from location to location (and inspector to inspector), so perhaps the question should be phrased as 'how common is it for this to be a requirement'?... I've been looking at 4/4 SOOW for feeding small rack-mounted distros, and 12/3 SOOW to feed stringers and powered speakers.

Code enforcement by AHJs, and code versions adopted as force of law are widely varied throughout the United States. The best answers that can be given on a forum going to be straight from the most recent version of the code. I don't have the 2017 code in hand, so the best I can do is respond from the 2014 code presently.

Let's start by assuming your AHJ considers your rack mount distros as portable switchboards. Then from the code:
NEC 2014 520.53

520.53 Construction and Feeders. Portable switchboards and feeders for use on stages shall comply with 520.53(A) through (P).

(H) Supply Conductors.
(1) General. The supply to a portable switchboard shall be by means of listed extra-hard usage cords or cables. The supply cords or cable shall terminate within the switchboard enclosure, in an externally operable fused master switch or circuit breaker or in an identified connector assembly. The supply cords or cable (and connector assembly) shall have current ratings not less than the total load connected to the switchboard and shall be protected by overcurrent devices.

(P) Qualified Personnel. The routing of portable supply conductors, the making and breaking of supply connectors and other supply connections, and the energization and deenergization of supply services shall be performed by qualified personnel, and portable switchboards shall be so marked, indicating this requirement in a permanent and conspicuous manner.
Exception: A portable switchboard shall be permitted to be connected to a permanently installed supply receptacle by other than qualified personnel, provided that the supply receptacle is protected for its current rating by an overcurrent device of not greater than 150 amperes, and where the receptacle, interconnection, and switchboard comply with all of the following:
(a) Employ listed multipole connectors suitable for the purpose for every supply interconnection
(b) Prevent access to all supply connections by the general public
(c) Employ listed extra-hard usage multiconductor cords or cables with an ampacity not less than the load and not less than the ampere rating of the connectors.

So, portable switchboards require listed cable per 2014 NEC.

Let's instead assume that your AHJ considers the rack distros as portable power distribution units:

Portable Power Distribution Unit. A power distribution box containing receptacles and overcurrent devices.

Back to the code:
NEC 2014 520.62

520.62 Portable Power Distribution Units. Portable power distribution units shall comply with 520.62(A) through (E).
(B) Receptacles and Overcurrent Protection. Receptacles shall comply with 520.45 and shall have branch circuit overcurrent protection in the box. Fuses and circuit breakers shall be protected against physical damage. Flexible cords or cables supplying pendant receptacles or cord connectors shall be listed for extra-hard usage.

So, again, the cords need to be listed for extra-hard usage per 2014 NEC.

Note that listed cable doesn't mean UL listed. It means listed by one of the nationally recognized testing laboratories (NRTL) who offers the relevant tests as part of their approved scope. NRTLs include UL, CSA, ETL/Intertek, TUV Rheinland, TUV Sud, etc.

In my day job we've worked with CSA, TUV, and UL via their 3rd party test data program.

[ProSoundWeb Community]