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Discussion in 'Lighting and Electrics' started by avkid, Nov 27, 2007.
Is this legal, if not what section etc.. forbids it?
Phil, can you give me some more background info on the... thing? Thanks.
Not mass produced or UL/CE approved.
That's all that is relevant.
This is not trivia, I don't have a copy of the NEC.
(anybody have one kicking around, 2000 or newer?)
strain relief ability of that configuration.
interesting idea though, perhaps there is a market for it?
I will try to check tomorrow, but I dont know that I have enough experience with the NEC to find an answer quickly.
E-string is what he was referring to I think.
Hmmm found this page when searching for the link to E-string. That's not exactly what you were looking for but it sounds like info you would like to know.
That is molded and not a daisy chain configuration without strain relief.
That is a big piece of the puzzle, thanks.
UPC (IEC) connectors are openable and not molded, it is not permitted by the N.E.C., for the same reason standard twofers are illegal: the connector is not rated or approved as a junction enclosure. See this post.
Any idea where I would find that section?
I know not to use it, I just need to prove why.
Either the NEC has changed the rule about connectors or plugs as interconnection devices, much less modification of the plug or electrical equipment so as to fit both cables or it is still a NEC rule I read and memorized in complying with when at all possible, but still cannot find but there.
What ever the case, done such a thing before... heck, you have never seen my stage pin sixfers... Very useful for testing gear at times or for certain applications. This or the L5-15R Hubbell mini-twist plugs for Kabuki drop stringers that are still in use where I work due to not having another option for being able to do such a thing. This until at least we get our old CamLoc plug vulconizer converted into a stringer volconizer. TBA future project.
In cases where there is no other solution possible and it's professionally done - the former of which this photo in my opinion does not comply with, than you have to do what you have to do and it is often not questioned. In the case of the above stringers, I even had to modify the strain relief to the plugs so as to fit two cables without damaging them. This was well thought out and finish in quality workmenship and has never been questioned on a jobsite. Not prefered but a solution for a problem.
In the case of this IEC stringer as it were, other commercial or manufactured solutions are available such as a power strip plugging in such cables - normally used, or if necessary for some show where necessary a splicing device.
Photo one 8/5 (L21-30P to CamLoc adaptor) is a modified type of adaptor that is in the spirit of the code, it's 8/5 conductors are sleeved with gas line where they break out and all is strain releiefed, vulcanized and weatherproof in the breakout etc. Gas line tubing is not UL recognized for sleeving wire or even a normal solution, yet it is both water and oil resistant, it also has a dual wall thick insulation over it with braided cloth support very similar to type W older days stage feeder cable insulation. Specifically compliant to sleeve the inner individual insulated conductors of a 8/5 type SO cable? No, within the spirit of the code and even going beyond it with individual conductor protection... yep. The break out point was also using silicone, glue, cable ties, adhesive lined heat shrink and self-vulconizing electrical tape. Totally water proof and not feasible to damage under use. Four years later after I made these, with use they are still in optimum condition. Not totally compliant as the CamLoc type plugs were not designed for a eight gauge wire and in general it's a type of adaptor frouned upon but still necessary. The reverse of this however would not be a code compliant adaptor. Also and very important is that a lot of R&D went into how to best do something like this. No expense was spared and it was not just slapped together. A huge amount of work went into developing and making such a thing, that is the concept of doing such a thing safely and properly.
Photo two is a 20a 19-pin Socapex type plug to 18 amp 7-pin Cir type plug adaptor used for powering up some marquee lights. The Socapex style plug is not designed for two cables to come out of it but it was made to work.
Photo three is a stage pin twofer possibility. It uses double wire ferrules that if you try hard can bairly fit inside the terminal. This given the strain relief or a normal 20A stage pin plug still even with fiberglass sleeved MTW wire, still does not well fit two sets of cable, and rubberized jacketed cable without modification to the plug or as in the above debate - commercially available does correct such a issue in other than the terminal not really fitting a double 12ga now combined 9ga wire well. Note also the white conductor didn’t quite make it under the strain relief - instead it got pinched and that’s a serious problem with strain reliefs not doing what they were designed to do if only designed for a single cable, now fitting twice as many conductors.
One will note the center plug in photo four shows the general concept of problems in doing any such thing as a plug as an interconnection device. While none were twofers, it is what could happen in general concept of concern. This in general is what I have a problem with. No overcurrent protection in something that can overload the rating of a plug - amongst other not designed to do it problems. Granted these plugs in theory melted down by way of touching something really hot (not confirmed on the second one, could have been high amperage, loose conductors, thinned out conductors in locallized resistance over a period of time) but still, the concept in general is you got a problem, it can fail in a serious way.
The fifth and sixth photos is how I have done it before in the past - this converting one power cable into muliple ones - in this case Edison to IEC for some LED light fixtures. Problems with the construction was overcurrent protection but in theory what the Edison is plugged into provides it and what is inside the box is rated for the current. Less compliant is the type of box used. A 1900 style electrical wall box is not designed for use other than in a wall. This unless the knock outs are welded so they cannot open up. In this case, due to the use of shielded Marithon connection blocks, it was not possible for any knockout to cause a problem with the wiring but still it was not the appropriate box (not figuring in CU sizing of the box either.) A better box will have been a NEMA 1 style pull box, than it will have been more appropriate. Still this is how one might do it, and how it was done - the photos are of the prototype. 12ga wire feeding if I remember correctly eight or nine IEC cables of 18ga. Note the safety cable ring also. Also note the electrical box is also grounded by way of that second wire coming out of the ground’s marithon block. Metak boxes need grounding. Since than for certain applications where I can I use thermoplastic boxes with good results. Not a fan of plastic for heat or impact resistance but it does have it's place.
This is my opinion. I don't use a plug or connector as an interconnection device unless I really need to and there is no other options where a power strip in the origional question will have worked sufficiently. At that point I need to do such a thing, there is a lot of design and quality into the workmenship.
One will also note in photo #5 that I did not mis-wire these IEC plugs. One would think that a blue conductor is hot - afterall even in photo #1, blue is a Z phase hot color, but if given the choice in Euro cable conductors of Brown/Blue/Green, Blue is neutral even if Brown in a more sensible way might seem more like ground or earth - especially if blue is a definate hot wiring color. Don't make this mistake when faced with Euro wiring. Just as the ribbed conductor on SPT/zip cord - household extension cord is the neutral, the hot on Euro cable is brown and the neutral in a non NEC code compliant coloring where both conductors would be considered hot, the blue is neutral and brown hot in a reverse of what makes sense type of way. This might be useful in remembering what is hot perhaps I hope. Wiring a IEC cable if Euro in color code, in the opposing way could be dangerous for the electronics it powers. A very important detail. Them Zenior diodes and stuff might blow in saving the equipment if power comes to them first, but if on the return side of the power source it gets more expensive in them not blowing up first say when a 120/208v fixture is switched for 120v but plugged into a 208v source. Been there done that... lots of ways to prevent it, this is only one way.
Sorry, ship, here's the link to the full thread.
To the OP, I think we all agree, whether or not it is or isn't allowed by the N.E.C., it's still not a good idea, if there's a reasonable alternative.
Thanks, Ship--I was about to point that out.
There are two important issues here:
1. Feeding a connector with a conductor and/or overcurrent protection larger than the rating of the connector is verboten. This is a good way to burn up connectors. The illegal 60Amp sixfer is a great example of this.
2. Article 520 acknowledges that a V-style twofer is a standard tool of the theatre by its allowance of SJ cord for this specific purpose, so two cables into the same strain relief are OK in this application.
When I look at the daisy-chained IEC device at the beginning of this post, I don't have enough information to judge it. What size conductors is it using? It likely has a 15A male, but I'd be surprised if the cable is 15A rated. If it used a 15A male, 15A females, 15A conductors, and was made in a workmanlike manner that allowed the strain reliefs to function, it might be acceptable.
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