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Thread: 200 Amp residential service

  1. #11
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    There is no rule that states you can drop the neutral 2 sizes. I have heard that for years but that is just an old wise tale.
    You can actually drop the neutral as small as the grounding electrode conductor. However, you need to make sure the calculated load is small enough for the conductor used.
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  2. #12
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    Quote Originally Posted by ramsy View Post
    Does that void the SEU listing for outdoor wet locations in raceway?
    Sorry, let me explain a little better. On the load side of the meter, between the meter enclosure and the MBP, and if the PVC is continuous I have stripped off the sheath of 200A SEU cable and used the single conductors (4/0, 4/0 and bare 2/0) and never had a problem. The 4/0's are XHHW and are marked. I have had cases where running PVC continuous between the meter enclosure and the MBP was not practical so I've stubbed a piece of 2" PVC out of the back of a 2" LB into the house just above the sill plate, I then installed a length of SEU cable with a 2" squeeze connector on the end (and enough of the single conductors to get to the meter enclosure), threaded it onto the end of a female adapter and glued it onto the PVC stub. Again, never had a problem.

  3. #13
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    Quote Originally Posted by Dennis Alwon View Post
    There is no rule that states you can drop the neutral 2 sizes. I have heard that for years but that is just an old wise tale.
    You can actually drop the neutral as small as the grounding electrode conductor. However, you need to make sure the calculated load is small enough for the conductor used.
    Dennis, I checked with an EI (who is also one of our CEU instructors and on the licensing board for the State) and he advised me that on a single family residence the norm is to drop down 2 sizes on a service.(at least that's here in NJ). If you look at SEU cable that's the way it's constructed. Shouldn't make any difference if you're using single CU or AL conductors.

    I started this thread because I generally use SEU cable and haven't installed a 200A service using PVC and single conductors in a long time. I wanted to check with some of my colleagues on wire sizes before placing an order. I was surprised to find out how many didn't know about 310.15(B)(7) and down-sizing the wire. After hearing their answers I started thinking "Maybe there was something I missed".

  4. #14
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    On the driveway physical protection , why can't a few pillars be installed for 'vehicular' safety?

    ~RJ~

  5. #15
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    Quote Originally Posted by romex jockey View Post
    On the driveway physical protection , why can't a few pillars be installed for 'vehicular' safety?

    ~RJ~
    I suppose you could do that but if you're married ask your wife is she wouldn't mind having 2 concrete bollards installed for protection

  6. #16
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    LOL, you got me there Goldone..... ~RJ~

  7. #17
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    Quote Originally Posted by goldstar View Post
    Dennis, I checked with an EI (who is also one of our CEU instructors and on the licensing board for the State) and he advised me that on a single family residence the norm is to drop down 2 sizes on a service.(at least that's here in NJ). If you look at SEU cable that's the way it's constructed. Shouldn't make any difference if you're using single CU or AL conductors.

    I started this thread because I generally use SEU cable and haven't installed a 200A service using PVC and single conductors in a long time. I wanted to check with some of my colleagues on wire sizes before placing an order. I was surprised to find out how many didn't know about 310.15(B)(7) and down-sizing the wire. After hearing their answers I started thinking "Maybe there was something I missed".

    My point is that the code doesn't state that you drop 2 sizes. That may be the norm but it can be misleading.
    Go to Southwire.com and see that they also make 4/0, 4/0, 4/0 seu cable
    They say I shot a man named Gray and took his wife to Italy
    She inherited a million bucks and when she died it came to me
    I can't help it if I'm lucky



  8. #18
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    Quote Originally Posted by goldstar View Post
    I have had cases where running PVC continuous between the meter enclosure and the MBP was not practical so I've stubbed a piece of 2" PVC out of the back of a 2" LB into the house just above the sill plate, I then installed a length of SEU cable with a 2" squeeze connector on the end (and enough of the single conductors to get to the meter enclosure), threaded it onto the end of a female adapter and glued it onto the PVC stub. Again, never had a problem.
    The problem with installing SEU in an LB is that you cannot maintain the required minimum 5X bending radius of the cable. To comply with the 5X requirement you have to use an elbow instead.

    Quote Originally Posted by Dennis Alwon View Post
    My point is that the code doesn't state that you drop 2 sizes. That may be the norm but it can be misleading.
    Quote Originally Posted by Dennis Alwon View Post
    Go to Southwire.com and see that they also make 4/0, 4/0, 4/0 seu cable


    I agree, but I seem to remember hearing about the two size reduction too.
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

  9. #19
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    Quote Originally Posted by infinity View Post
    The problem with installing SEU in an LB is that you cannot maintain the required minimum 5X bending radius of the cable. To comply with the 5X requirement you have to use an elbow instead.



    I agree, but I seem to remember hearing about the two size reduction too.
    I'm sure you're correct. The problem I have with using an elbow is that the hole you would have to cut in the siding would have to be oblong to accommodate the sweep. If I did that in this new Hardiplank siding the builder will go ape.

  10. #20
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    Quote Originally Posted by goldstar View Post
    I'm sure you're correct. The problem I have with using an elbow is that the hole you would have to cut in the siding would have to be oblong to accommodate the sweep. If I did that in this new Hardiplank siding the builder will go ape.
    I agree and admit that the LB is easier to install for that reason and looks better when finished. There is always a chance with the LB that an inspector could make you change it.
    Rob

    Moderator

    All responses based on the 2014 NEC unless otherwise noted

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