power wiring in duct work
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  1. #1
    Join Date
    Dec 2004
    Location
    newton,mass.
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    6,109

    Angry power wiring in duct work

    We installed some make up air units and the electrician ran the power wiring through the duct work up to the motor. I have seen this from time to time but never had it done on equipment I will be servicing. Or done so poorly. The MC is just floating around inside the duct work with no support. When they went through the fan deck they looped the wiring and it is also just floating around. The jack ass used wire ties to hold it and they have pulled loose even before the units have been started. When it was seen what they were planning on doing they were told it was unacceptable and they said they would change to the roof penetrations we provided. After we left they did it anyway. When approached about it the electrician said it's code so screw you. We know from past experience that there will be problems ... like noise, like vibration, like the MC being cut into.

    So, does anyone know the code on this?
    Have you had this problem, if so how did it get resolved (if it did)?



    .
    "Nothing else can poison our culture, corrupt our society or ruin the character of our people like unearned money or unearned opportunity." -- James R. Cook

    "Fooling around with alternating current is just a waste of time. Nobody will use it, ever." Thomas Edison, 1889.

  2. #2
    Join Date
    Mar 2003
    Posts
    7,321
    dont know the code reference, but pretty sure it doesnt meet it. I know someone will know the answer, and probably can cite paragraph. google the question, you just might find it.

  3. #3
    Join Date
    May 2007
    Posts
    732
    Per 300.22 (B), MC cable is permitted in ducts or plenums used for environmental air.

    See 330.30 for approved methods of securing and supporting MC cable. It must be secured every 6 ft. and cable ties are acceptable. Obviously some judgement is called for regarding suitability of any given means of support.

    About cable being looped or just floating or subject to vibration, Article 110.12 says "Electrical equipment shall be installed in a neat and workmanlike manner." Good luck with citing that article to the electrician.

  4. #4
    Join Date
    Aug 2011
    Location
    Los Angeles, CA
    Posts
    34
    Are they your subs or the buildings?

  5. #5
    Join Date
    Dec 2004
    Location
    newton,mass.
    Posts
    6,109
    OK here goes ... they are being changed. Turns out the contractor was not to happy with many of the electricians shenanigans. He called his boss and had him come out. They had much to talk about ... His boss looked them over and said even though it sort of meets code they were going to cause problems. He agreed vibration and rattling were a real concern.

    Thanks to all that posted ...


    .
    "Nothing else can poison our culture, corrupt our society or ruin the character of our people like unearned money or unearned opportunity." -- James R. Cook

    "Fooling around with alternating current is just a waste of time. Nobody will use it, ever." Thomas Edison, 1889.

  6. #6
    Join Date
    Dec 2004
    Location
    newton,mass.
    Posts
    6,109
    Quote Originally Posted by redcell09 View Post
    Are they your subs or the buildings?
    Not ours, first time working with them. It's the lead electrician that has an attitude. The other guys are OK.


    .
    "Nothing else can poison our culture, corrupt our society or ruin the character of our people like unearned money or unearned opportunity." -- James R. Cook

    "Fooling around with alternating current is just a waste of time. Nobody will use it, ever." Thomas Edison, 1889.

  7. #7
    Join Date
    Dec 2004
    Location
    newton,mass.
    Posts
    6,109
    Quote Originally Posted by fxb80 View Post
    Per 300.22 (B), MC cable is permitted in ducts or plenums used for environmental air.

    See 330.30 for approved methods of securing and supporting MC cable. It must be secured every 6 ft. and cable ties are acceptable. Obviously some judgement is called for regarding suitability of any given means of support.

    About cable being looped or just floating or subject to vibration, Article 110.12 says "Electrical equipment shall be installed in a neat and workmanlike manner." Good luck with citing that article to the electrician.
    Thanks, that is exactly the code he stated today ... it was the workmanlike manner that failed him.


    .
    "Nothing else can poison our culture, corrupt our society or ruin the character of our people like unearned money or unearned opportunity." -- James R. Cook

    "Fooling around with alternating current is just a waste of time. Nobody will use it, ever." Thomas Edison, 1889.

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