What is wrong with this picture

Actualy, radman was posting about the Par 56. hey, is that really in some book, that rule? man...if you are actually quoting some rule there, mad props to you man!!

Yes, it seems to me that Ship is suggesting exactly waht you said, peter. The only other possibility i see right now is that somehow the plugs were pulled apart alot, leading to high resistence between the two, causing the heat.

There aren't many explanations that i see for the conductor between the hot and neutral of the female plug either....we have mentioned water of some sort, ,possibility it rained on the plug, and the condensatoin inside allowed electricity to g between the plugs. I think it improbable that there was a wire between the pins, but the plug might have been broken, one side of the cover might have been off, allowig something metal to occasionally connect the two pins. Actually, I am wondering if the cable might have been sliced, letting two sliced wires, ,the hot and neutral, make contact sometimes.
 
hmm... I just spent a few minutes looking arround online seeing if there was anyway I could check what if anything NEC regulations: Article 520.68 (A) (3) is. No luck though. Radman, if you are seriously quoteing that.... WOW lol, if not, hey, you'll have given us all a laugh!

I agree with you jajahwarrior. Now where's ship to tell us yes, or to add more confusion to this! :)
 
As Brian reaches for his copy of NEC2000 Handbook and thumbs pages past the drawing in 520.1 of an acceptable two-fer ...

520.68 (A)(3)
“High Temperature Applications. A special Assembly of conductors in sleeving not longer than 1.9m (3.3ft) shall be permitted to be employed in lieu of flexible cord if the individual wires are stranded and rated not less than 125°C (257°F) and the outer sleeve is glass fiber with a wall thickness of at least 0.635mm (0.025 in.).
Portable stage equipment requiring flexible supply conductors with a higher temperature rating where one is permanently attached to the equipment shall be permitted to employ alternate, suitable conductors as determined by a qualified testing laboratory and recognized test standards.”
(“The requirements of 520.68 (A)(3) cover the connection of high-temperature equipment including stage lighting fixtures, which often do operate at elevated temperatures. High-temperature (150°C to 250°C) extra-hard-usage cords are, in general, not available. Less than extra-hard usage cords are, in general, not available. Less than extra-hard usage cords are limited to 3.3 ft in length to reduce the likelihood that they could be placed on the floor or other area where they might be damaged by traffic or moving scenery.”)


You won’t find a copy on line unless you join. Thinking I’m going to be joining this year, it’s only $130.00 and I’ll get to vote in changes to the 2008 Code, plus as a member have a title under my name something like Member of the NFPA than also be able to use the graphics they send me. Don’t know where they got my name from but about every year of so I get sent an application. Last time my application got lost in red tape of attempting to have the company pay for the membership I would be representing for them. Don’t know if they offer student memberships but once a member you get discounts on the books and news letters.

Another option might be to get the school to buy one, or shame the principal or who ever controls the purse strings into getting you a copy when you are doing them a big favor. That’s how I got my copy of the Chicago Building code which was not cheap either. Shamed one of our board of directors into buying me a copy so we could become more compliant as a theater, while I was also doing a show for him which I will have done anyway without pay. At very least, perhaps the school library can purchase a copy.

For now, while very expensive, buy the 2005 Handbook version - it’s worth it. Or perhaps you will be able to find a 2002 version at a cut rate, than just buy the 2005 code changes book to supplement it at a more reasonable cost.

Reason I say this specific book is because in addition to a lot of dry language, the handbook version goes into explaining and expanding on the rules in addition to showing diagrams and photos. In other words, 1,160 pages in a 8.1/2x11" book. This is a good investment and as long as you buy one handbook version, all you will need is the change book every three years afterwards.

There is many forms of the NEC on the market and by quite a few publishers all taking liberties in what parts they cut out to conserve space. Especially in the guidebook or Illistrated Guide books, they cut out and cut down on a lot of the specialized sections such as theater that are not needed for a more broad sense of it most trades people would be interested in.

The normal version of the NEC if by the NFPA as a publisher, otherwise is very dry in reading thus in getting board, you tend to gloss over things when they go over your head. This Handbook copy with it’s pictures and descriptions makes it easy to understand. In other words, do not buy the Illustrated or normal Guidebooks to the NEC if you want to look at theater applications of the Code.
 
Now as for Radman’s whack at it, in general he is correct. In general.

Wires that are solid don’t put any more of a strain on a lamp than stranded ones. In fact, since solid wires in this theoretical sense kind of support themselves, they would probably put less weight or pulling pressure depending upon his meaning "straign on the lamp." Same thing with if the idea of putting strain on the lamp is in a solid wire being worse for connectivity to the lamp than a stranded one in putting strain on it. The solid would probably put less of a strain on the lamp because it retains it’s shape. One might find solid wire used in flash lights for instance.

The rest of the sentence is basically correct in essence - the wire being solid would most likely not be available with a heat rated jacket on it in the proper wire gauge. Thus in being the wrong insulation, pose a fire hazzard though I doubt that the insulation would catch on fire. The shock hazzard on the other hand should the insulation melt off is correct. Is this not the case often with normal PAR cans however? That's why Kupo is selling lamp adjustment knobs and their testing lab otherwise requires a screened cap over the hole in the rear of the fixture. I find this interesting as nobody else has to have this cap to get listed by a testing facility such as UL, but I certainly understand the necessity of it even if it does not allow for adjustment of the beam.


By the way, that fiberglass sleeved conductors is as opposed to other mulit-conductor types of cable that is rated for the temperature such as Rockbestos that would also be acceptable. Also the use of fiberglass sleeving would not exclude the use of properly heat rated conductors; it is in addition to the requirement of them and only a sleeve not a type of wire.
Some conductors such as TGGT and SF-2 will come with a fiberglass sleeving over the individual conductors which might be argued that such wire does not require the extra over sleeve of 0.025" thick fiberglass sleeve; but it would be incorrect unless the conductor fiberglass over coating were of the same thickness.
In general, these heat wires come in Teflon and Silicone insulation and both with and without the braided fiberglass over it depending upon the style. This has no overall effect on it’s temperature rating as silicone coated SF-2 with and without the braiding is rated for the same temperature. I prefer fiberglass sleeved SF-2 wire because after the silicone melts, at least you still have what's left of the fiberglass coating on it protecting you, but it still melts just as easily as non-coated ones in similar applications.


Now as for the NEC requirements cited, 520.68 talks about the fixture cord as a supplement to Article #406 which is the fixture cord compliance for more normal fixtures such as the ones Mayhem is using because they are probably not listed for use on the stage. This is a rock and roll aluminum PAR can which arguably given Article 520.68(A)(3) would be non-Code compliant because of it’s thermoplastic SJT cord normally in use that does not comply with the above.

Rock and roll PAR cans instead are built around Article 406 and 410 for compliance given the differing classification of use for them. In other words, it can be argued that if your par Can has a SJT wire on it such as most rock and roll store bought cans will, it cannot be listed for use on stage. Remember that compliance for rock and roll falls under the more broad "Places of Assembly" classification which allows things like the use of SJ wire when supported by the truss instead of the normal hard service cords.

Given most of them probably are listed for stage and studio use, the testing lab must have written off on the use of that type of cord, or it was an overcite given this rule. This rule also has applications in saying why fiberglass sleeved wires cannot be used for a twofer in additon to the rules against using a plug for an interconnection device or the theater specific rules on twofers being molded and extra hard service in construction.


I'm now off my point...
In any case, Article 520.68(A)(3) does not mention at all the connection to the lamp base, socket as it’s called or lamp itself. It is only talking about the fixture whip which was not shown in the photo thus cannot be commented upon. In other words, in not mentioning the means of attachment of a lamp to the fixture cord, it’s going to be covered in Article 410 - Luminaries (Lighting Fixtures), Lampholders and Lamps as a general covering all theater and other lights with very few exceptions such as arc lights must comply with no matter the application.

Let’s see, Article 410.3 Live Parts, this photo does comply with in that Mayhem was the one that removed the shrink tubing thus before he removed it, the fixture was in compliance with this.

Article 410.17 also does not matter in that we are not talking about the ground also not the subject of the photo.

What we are looking for is section VI. Wiring of Luminaries (Fixtures)
Article 410.22 and 410.24 would be the ones Radman is looking for where the question of compliance with heat is involved. It also says to see article 402 for types of suitable wire for the wattage or heat of the fixture.

Those of you looking for the rule on the “positive and negative” or hot and neutral will want #410.23 and #410.42(A) which says the same thing.

Stranded wire is 410.28(E), one might also look at (D) which sends us to Article 110.14 for the suitable means of making a splice or tap.

One will note that means of attachment of the lamp to the conductor is not mentioned for other than screw based lamp types in a general look at the NEC. It's probably in 110.14. In general this lack of lamp base on a fixture much less lamp type designed to work with one was the first thing I saw. In not mentioning a lack of lamp base as the first and most important thing, any number of things talked about such as heat wire, solid verses stranded, lack of solder or crimp splice etc. are moot.


There is also that stickler cover-all rule about “done in a professional workmen like manner” which while the wiring was neat, was not professional or what any workmen that did this type of a thing for a living would be caught doing.
 
ok...great...but what about tht threefer? wasn't the whole last post about the par?

Ship, I didn't bother to read very well that entire last post, but I am wondering, I have a par 64 at my youth gruop and the wiring onthe side is completely burned through, melted, ,dead. like, the wire itself i think was burned through, or oxydized to the point of brekaing. To fix it, what do i need to do? I wsa thiking just replace the wire, but now that you point out all these rules...1) where can I get the wire 2) do i need to replace the entire ceramic lug, which would have the leads on it? 3) is it worth it ? :)
 
What is this, now I have to play catch up with you or do you block out Peter's messages? The Threefer is already about as figured out as it's going to get.

As for wiring on a PAR can, look for it in a new post under the lighting area section later tonight.
 
Wow, Ship and Radman, that was impressive! I would have difficulty quoting any source like that! let alone a technical reference! Kudos to both of you! And thanks for all the info!

I must claim that I was at an unfair advantage for this question b/c I have hardly ever heard of the NEC regulations before this thread, let alone read (or even seen for that matter :) ) the regulation book! lol

I'll have to look into that book, (but like everything else I do, it comes down to $$ :) ) Be sure it is up at the top of my list of books to buy, especially if I start leaning more and more towards doing this kind of things for a living. A quick question, does this book cover all kinds of electricial wireing type stuff, or more just theatrical stuff?

To do what seems to be my thing now; Basicly what ship's answer to the orignal question is saying is, the wrong kind of wire was used, and it was not properly attached. The wire was not rated to cary the wattage and handle the heat used/produced by this bulb.

Have we actually come to some kind of conclusion to this thread?!?! wow! I dont know what I am going to do without this thread! (Looking at other new threads though... it looks like a new thread has been started!! yay!!)
 
The NEC is the National Electrical Code which is while US based, sort of the intronational guidelines for all types of electrical wiring. It comes from the fire department aka the NFPA National Fire Protection Association that beyond the electrical code has say in a few other applications around construction but this is the most well known.

Their purpose for these "guidelines" is in preventing the fires associated with early application of electricity to buildings as it was much more dangerous than gas lighting.

The NEC while not law, is normally adopted in whole with only slight changes by your local authority that is charged with making and enforcing code. It thus as a national set of standards, and in general accepted by all localities is for all intensive purposes "the law" were wiring no matter if it's a boat house or nuclear control room.

That said, Croft/Summers, American Electrician's Handbook, and various books on electricity by Audel are very good texts on the subject. Most books on basic wiring will be based off of explaining the NEC guidelines. Just a question of how theater they get as with guidelines of the NEC. Theater books on lighting to a small extent make up for this lack of info in other texts, but short of doing this all the way, you in my opinion would be well serviced by reading all three sets of sources in general. More so, studying them. Get a Electrician's Pocket book for starters. Read it, first as it's cheap than broaden from there, first with a book on theater lighting than perhaps a NEC book etc. Eventually by the time you are getting into "Handbook fo Electric Power Calculations" that's beyond me at this point for need to know, you will have the subject well covered. In theater books, look for books both from today and the early 70's and before in skipping the 80's where wiring is concerned.

Most important, read and absorb what you can. Don't think I ever got past grounding in my cover to cover read of the NEC. After that, when things came up, I read the section but I'm yet to read it cover to cover also beyond skimming thru it. Other books and instruction for the most part has made up for it in stuff I understand well. Get into transformer taps etc. on stuff I don't use and while I might remember something about details, I would not be ready to do so.

Hope it helps. Good start on the other photo III. Good start indeed as a off the cuff hint. Told you it would be easier. Given the expectations, perhaps just a little refinement of what thoughts are provided so far.
 
Well I must say that I am extremely impressed by the progression of this topic and can honestly say it passed my expectations when I first posted the picture.

As Peter has very nicely pointed out - well done to Radman and Ship for taking this common situation and refering it back to the NEC guidelines. A sort of example of theory in practice.

Thanks!!
 

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