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  1. #1
    Join Date
    Oct 2010
    Location
    AZ
    Posts
    647

    Electrical Question-- Wiring size

    Hey guys, I have just been wondering about factory wiring on residential units. Seems like the wire sizes they use a lot of the time is under sized according to the charts and smaller than wiring feeding the unit. I am assuming factory wiring is approved to be as it is but many times it is located in an uninsulated and un-cooled section of the unit. How are they getting away with this? Is it because of how short the run they have is?

    Also, I have been seeing some with aluminum factory wiring. Should Al to Cu connections have that aluminum wiring gunk on it? They seem to be going more to aluminum everything including all aluminum coils. Is our industry going to end up running aluminum linesets too?

  2. #2
    Join Date
    Feb 2013
    Location
    Phoenix, AZ
    Posts
    198
    NEC covers the branch circuit wiring and requires it to be a certain size based on the overcurrent device (breaker) rating. Internal factory wiring is held to a different standard (like UL). For a similar reason the factory cord on your vacuum pump is probably not 12 AWG even though it plugs into a 20A recep.

    Sent from my ADR6300 using Tapatalk 2

  3. #3
    Join Date
    Oct 2012
    Location
    Sacramento,ca
    Posts
    196
    Quote Originally Posted by dijit View Post
    Hey guys, I have just been wondering about factory wiring on residential units. Seems like the wire sizes they use a lot of the time is under sized according to the charts and smaller than wiring feeding the unit. I am assuming factory wiring is approved to be as it is but many times it is located in an uninsulated and un-cooled section of the unit. How are they getting away with this? Is it because of how short the run they have is?

    Also, I have been seeing some with aluminum factory wiring. Should Al to Cu connections have that aluminum wiring gunk on it? They seem to be going more to aluminum everything including all aluminum coils. Is our industry going to end up running aluminum linesets too?
    one company tried running aluminum linesets in our area, it was a massive failure.

  4. #4
    Join Date
    Jan 2007
    Location
    NH
    Posts
    248
    As said by DDC_Dan, they are not bond by NEC codes, just like power utility workes bringing power to your house.

  5. #5
    Join Date
    Aug 2001
    Location
    Pavilion, NY
    Posts
    2,152
    It is sized in accordance with article 440 of the Nec which is different than article 210 which most are familure with. Article 440 is used for definite purpose fixed motor loads.
    ...

  6. #6
    Join Date
    Feb 2013
    Location
    Phoenix, AZ
    Posts
    198
    Quote Originally Posted by kangaroogod View Post
    It is sized in accordance with article 440 of the Nec which is different than article 210 which most are familure with. Article 440 is used for definite purpose fixed motor loads.
    Again, NEC (including Article 440) covers only the branch circuit wiring, not internal factory wiring. From the NEC:

    90.2(A) Covered.
    This Code covers the installation of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment and raceways; and optical fiber cables and raceways for the following:

    (1) Public and private premises, including buildings, structures, mobile homes, recreational vehicles, and floating buildings.


    90.7
    It is the intent of this code that factory-installed internal wiring or the construction of equipment need not be inspected at the time of installation of the equipment, except to detect alterations or damage, if the equipment has been listed by a qualified electrical testing laboratory that is recognized as having the facilities described in the preceeding paragraph and that requires suitability for installation in accordance with this Code.

  7. #7
    Join Date
    Dec 2011
    Location
    Twin Cities Minnesota
    Posts
    242
    That wire you think is alum....,cut it back,I found they "tin" it at factory!

  8. #8
    Join Date
    Dec 2012
    Location
    columbus, OH
    Posts
    2,042
    Ive gotten replacement burner blocks for stoves that specifically state copper conductors only sure enough the replacement they give me has Al wire.

  9. #9
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,311
    The insulation for the internal equipment wiring is rated at a higher tempature. Also, the wire can get hotter since it's surrounded by metal, where house wiring can go through wood and touch other flammable materials.

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