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Hi Need Help On A Dry Line Issue

Discussion in 'Lighting and Electrics' started by sparkienot, Feb 17, 2007.

  1. sparkienot

    sparkienot Member

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    Does Any Body Know What The Chicago Code Is For How Many
    12 Gauge Stranded Wires You Can Put In A Conduit,
    I Was Told That Because Of Being In A Theater, Live Music Venue
    The Rule Is Different Than Other P[laces, And You Could Put As Many As The Conduit Could Hold , We Have A J Box 24x 24 X 12 To Another Like It
    That Has 4 Socopex And 4, 7 Pin Motor Connectors On It
    Thats 77 Wires .in This Set Up There Are 2 3inch Conduits And 2 1 Inch Conduits Connecting These 9dry Line Boxes Oh An One 3/4 Inch Conduit For Dmx
    Anyone No About This
    Thanks
     
  2. gafftaper

    gafftaper Senior Team Senior Team Fight Leukemia

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    I bet Ship knows the answer to that but I rarely see him post in the new member board. Repost your question in Lighting and I bet You'll get the answer you are looking for.

    Oh and welcome to the booth!!
     
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  3. ship

    ship Senior Team Emeritus Premium Member

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    "Dry Line Issue" Interesting terminology, where does such a description come from? I'm thinking rope that's wet or not.


    Here is a start, have not fully re-red what I last read like 12 years ago, but if I find anything more of interest I'll let you know. (Interesting story on how I got my copy of the Chicago Building Code. It was my payment for designing two one act plays that one of our board of director's - a higher up city employee / also actor member wished to do. Great show - at least one of them that I remember "The Nose". Anyway, I kind of fealt that all theaters and their TD's should have both a copy of the NEC and the local building code and be familar with them. I was at the time reading the NEC but had no idea on the local building code. This book was my payment for a great play.

    Way back when I heard something like a wives tale about Chicago Electrical Code saying something like four wires per conduit no exceptions. At that point I had much the same concerns you do now. That is a wives tale and there is certain classifications to what you have such as this being controlled "panelboard" circuits of "Varying" duty requirements. There is no exemption for "theater wiring" persay but the run of conduit/outlets you talk about are not the general norm for line voltage wire/fill requirements, it fits into a number of not specific to theater classifications of what is being done but is normally safe and compliant to do under permit.

    This all assuming that multi-cables are not run in the conduit, (Cables run thru conduit as other than a say FOH temporary power situation is against code,) instead individual and marked conductors are in the conduit. Also panel mount not cord mounted outlets are attached to the end boxes of your conduit runs and not some form of cord coming out of the connection/junction/splicing box, that could be but is not always compliant... Also assuming that the hoist power and control/datta is in their own conduits as they are for a dissimilar purposes and have different requirements plus standard practice rules about them. Possible to share conduits with the dimmer circuits, but only in very speicfic instances such other things would have to comply with. Lots of little technicalities to the Chicago Electrical code and NEC it's in general based upon but in a more refined way.

    I cannot comment on what you have in not seeing it, or in not having a electrican's licence, but would suspect that if it looks professionally done, it probably was by way of a licenced electrician who pulled the proper permit and had it inspected by the city. I have done similar dimmer/patch panel to output in the house work under the supervision of a licenced electrican (I am not), which was also inspected by the city inspector and approved in the past.

    The use of a 3/4" conduit to run your data is a more recent standard as opposed to cable tieing the data cable to the outside of the power cable conduit as was done in the past, and that such a individual conduit run is followed in general in your case, it would say the rest of the applicable parts of the code were most likely followed in compliance. Your hoist controlling conduit I would know less about other than possibly following the above, than again might be more straightforward in compliance dependant upon the type of hoist also. I would assume that the hoist conductors are in their own conduit and not in the same one as the dimmer circuits.

    I would also assume that the gauge of wire used would be in compliance with voltage drop at full load requirements where applicable. Could still mean #12 ga wire dependant upon the situation for this application but not always.

    You would also unless someone else knows better, need one dedicated neutral per circuit in this application as opposed to one or more in this run that would be of a larger AWG and do the neutral for more than one circuit. The neutrals would also be isolated from ground, but the ground in this case could be tied into more than one circuit as long as appropriately sized for the possible loading.



    Unless it's changed from my 1994-1995 copy of the Chicago Building Code here is what I read. (You can find this book in most Chicago Public Libraries):

    Chapter #14-60:
    #14-60-100 is important to read as your theater exemption rules, "Remote Control, low-enery power and signal circuits."

    Than:
    #1414-32-030 "Cranes and hoists," and if other than specificied in it, #14-241180 "fractional horsepower motors"

    In general to conduit fill:
    #14-20-1180 (87-346.7.) "Number of Conductors in Raceway"
    "One conduit shall not contain more conductors of a given size than are specified in Tables 4 to 11 of Sections 14-68-050 to 14-68-100, respectively of this title.
     
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  4. gafftaper

    gafftaper Senior Team Senior Team Fight Leukemia

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    Told yah he would know. :) The man knows everything electrical.

    Thanks as always Ship, that was interesting reading, and I had nothing to do with the initial post.
     
  5. ship

    ship Senior Team Emeritus Premium Member

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    No, I very specifically do not know everything electrical - I'm still learning myself and do not in any way consider myself expert persay. On the other hand for what I most do... perhaps I know it often better than others, and perhaps for what I retain in knowledge, what I get a feeling about in being wrong by way of retained knowledge is sufficient often, but nope.. I am not an expert. Lamps.. perhaps I'm working on that anyway but wiring... I do my best and always check or ensure.


    Here is what I found so far in further complete re-reading of the Chicago Building code - or at least my 1994-1995 version of it which I once read years and years ago.


    14-20-110 (87-300.11.) Conductors of Different Systems
    “Conductors of signal or radio systems shall not occupy the same enclosure with conductors of light or power systems except as permitted for...., for remote-control, low-energy power and signal circuits in Section 14-60-230 of this title.........”

    14-20-120 (87-300.12.) Number of Conductors in Raceway
    “In general the percentage of the total interior cross-sectional area of a raceway to be occupied by conductors shall not be more than will permit a ready installation or withdrawal of the conductors and dissipation of the heat generated without injury to the insulation of the conductors. See the following sections of this code: conduit, Section 14-20-1180; electrical metallic tubing, Section 14-20-1420; surface metal raceways, Section 14-20-1620; underfloor reaceways, Section 14-20-1700; cellular metal floor raceways, Section 14-20-780; wireways, Section 14-20-1950; auxiliary gutters, Section 14-20-2460; theaters, Section 14-32-340; sound recording, Sections 14-32-730 and 14-32-740; and remote control, low-energy power and signal circuits, Section 14-60-120.”

    14-20-1180 (87-346.6.) Number of Conductors in Raceway (RMT)
    “One conduit shall not contain more conductors of a given size than are specified in Tables 4 to 11 of Sections 14-68-050 to 14-68-100, respectively of this title.
    14-20-1420 (87-348.6.) Number of Conductors in Raceway (EMT)
    “One tubing shall not contain more conductors of a given size than are specified in Tables 4 to 11 of Sections 14.68-050 to 14-68-100, respectively, of this title.

    Article XXV-Auxiliary Gutters
    14-20-2420 (87-374.2.) Purpose
    “Auxiliary Gutters, used to supplement wiring spaces at meter centers, distribution centers, switchboards, and similar points of interior wiring systems, may enclose conductors or but-bars, but shall not be used to enclose switches, overcurrent devices or other appliances or apparatus.”

    14-20-2460 (87-374.5.) Number of conductors in Raceway
    “Auxiliary gutters shall not contain more than 30 conductors at any cross section unless the conductors are for signaling circuits or are control conductors between a motor and its starter and used for starting duty. The sum of cross sectional areas of all contained conductors at any cross section of an auxiliary gutter shall not exceed 20 per cent of the interior cross sectional area of the gutter.”

    Something of interest/curious I found not related:
    14-20-2780 (87-384.26.) Number of Overcurrent Devices in One Panelboard
    “Not more than 42 overcurrent devices, other than those required for the mains, shall be installed in any one enclosure. For the purposes of this Section a two pole circuit breaker shall be considered two overcurrent devices; a three pole breaker shall be considered three overcurrent devices.
    Panelboards shall be equipped with physical means to prevent the installation of more overcurrent devices than that number for which the panelboard was designed rated and approved. (See 14-16-1010(f)).”

    14-20-2790 (87-384.27.) Overcurrent Protection
    “Except where the panelboard is approved as service equipment and is being used as in (a-3) of Section 14-16-640 a panelboard supplied by conductors having overcurrent protection greater than 200 amperes shall be protected on the supply side by overcurrent protective devices having a rating not greater than that of the panelboard. Snap switches rated 30 amperes or less and installed in a panelboard shall be protected by overcurrent devices not in excess of 200 amperes.”


    14-28-860 (88-520.5.) Auditorium Wiring Methods

    [Very curious in it’s literal concept but The Stage, is covered in the next section so in theory this concept would not include the fly system itself, but there is no specific exemption here that would clarify this. (14-28-870h later about suspended boarders does not cite this safety cable of it for instance however so such a rule probably does not have it’s concept for the stage non-audience accessible area perhaps. Also curious about solder terminals on foot lights in this 14-28-870 chapter.) Still never seen a ceiling chandelier over the house in a proper theater space that had a safety cable on it or at least two point separate derived suspension. Assuming that the wiring to the fixture was not sufficient to provide an alternate means of support it’s curious. It would mean however in a more specific sense, that any FOH lighting support or bars, would need a separate alternate means of support of that bar which could in theory be say individual hoists (more than two) say in supporting a truss or pipe where if one failed, the others could be sufficient. This or a chain support hoist mechanism as not mentioned which would or could be sufficient all around without the alternate safety necessity. As for the overhead chandeliers that get lowered down so as to change lamps... I don’t know how such things given the below gets grand fathered or compliant.]

    d. “Ceiling fixtures in auditorium or other parts of the theater, which, for the purpose of lowering the same, are suspended from steel cable, shall have an additional means of support which shall in itself be sufficient to safely support the fixture and which shall be entirely independent of the support afforded by the cable.”


    14-28-900 (88-520.9.) b. Portable Incandescent Olivettes and spots
    “Where asbestos covered conductors pass thru the metal, an approved bushing shall be employed for each conductor and the conductors shall be so anchored as to relieve the connections of any mechanical strain.” [This is 1994/1995 Chicago building code and the chapter follows carbon arc followspots and boarder lights. Would have to check the more recent code books but according to this, asbestos cable fixtures are still recognized under code for use. This also that all conductors shall be kept at least ½” from the metal of the enclosure and be solder type. Means that S-4, and most all other fixtures were not acceptable by code at this point by way of that ½" from the body of the fixture - though means of support of the lamp base is not clarified as part of the enclosure or support mechanism, and other concepts of solder type terminals would tend to limit what’s compliant to stuff made last in the 1970's. Hope the code has been updated since the 1930's after the publishing date of my 1994/1995 copy.]

    Read 14-28-920... it’s insane and inane by way of what is specified and not concepted for actual use.



    Also in my Chicago Code book, 14-28-940 about “Portable Conductors” is very telling of where the industry was even 12 years ago, much less useless - like at least 20 years out of step with the industry. Unless a more recent Chicago Code has seriously updated this info which is hopeful, I would say follow the current guidelines presented by the NEC for the stage and consult the Chicago Code to see where problems might be in out of date concepts of compliance. Best judgement after that as well as talking with the inspector of and contractors for your application in gaining their own incites as to how to deal with what’s specified verses what’s appropriate. Most likely what’s in the NEC will be sufficient and better. The above “Olivettes and Spots” is in reference to a type of Fresnel and PC spots - not Leko’s meaning premium early 1960's technology yet they, footlights and boarder lights are still in 1995 at this point are still the only stage lighting fixtures mentioned acceptable for specific compliance in the code. Last reading of this book like 12 years ago, I didn’t as well understand it’s concepts and easily wrote off many such sections as being out of step. Made me follow the NEC more in my own work and write off most of the electrical part of this local governing law of what I do book. I book marked most of the other than electrical part of the book in the overall 1349 page building code book where code compliance was concerned as being important... interesting that the electrical section was not way back when.

    14-28-940b at least offers not so distant past code compliance to a past Controlbooth discussion about wood framed portable switchboards concepts in such things being ok’ inside a wood box, as long as it has a sheet metal liner. Again, the 1994 book I’m looking at seems 20 or 30 years out of date by way of reality and good practice even for the era it was written. Still while bad practice and archaic, in concept even during this more modern period such things were still acceptable. This as long as such conductors within the panelboard were asbestos as mentioned in part d, use of the earlier discussed as not so good these days in concept wood framed switchboard that’s tin lined, and wired with asbestos wire would be acceptable. Also overcurrent protection will be of the fuse type. No worries... in 1994, “All circuits leaving the switchboard shall have a feuse in each conductor. Circuits from portable switchboards directly supplying equipment containing incandescent lamps of the medium base or smaller types shell be protected by overcurrent devices having a rating or setting of not more than 15 amperes. Circuits for heavy-duty lampholders may be used, if overcurrent protection conforms to provisions of article II of Chapter 14-16. Other circuits shall be provided with overcurrent devices with a rating or setting not higher than the current required for the connected load.”

    Just reached the end of the 1994/1995 guidience and Chicago rules on theater wiring... No mention of an overall compliance with the NEC that’s further refined by the Chicago Building Code anywhere in the electrical part of the Code. Means Lekos - especially S-4 Lekos are not acceptable by code by way of this book from what I read. Also means lots of other curious specific to what’s specified concepts or lack there of. For instance, nowhere in the code did I read about a requirement of “extra hard service” cable for use in all conditions or conditions other than direct support by truss or pipe and not other instances such as the floor or cable drop as specified by the NEC for similar over 100 seat places of assembly.

    More later as I continue re-reading the Chicago Building code. Fascinating that while I don’t consider 1994 that old, it’s a world and a day different than what I would hope the current Chicago Building Code electrical section specifies for use.
     

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