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An engineer's shop panel, anbody see errors?

Post in 'DIY and General non-hearth advice' started by Highbeam, Jul 18, 2013.

  1. Highbeam

    Highbeam Minister of Fire

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    I landed the final circuit on the subpanel last night. I installed this subpanel in my shed last year and had it inspected with only a few circuits. Since then I've added more circuits and I think I'm done. Ready for another inspection. Do you think it's okay? See any errors? Detached shed so isolated ground and neutral bars. The fat wires on the left are for the short run to a welder plug. The feed is only 60 amps.

    Attached Files:

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  2. ScotO

    ScotO Guest

    Only thing I see that may throw a flag is the neutral wire you have piped into the double pole breaker on the lower right side of the panel.....with the black tape around it, I'm guessing you are designating it as something other than a neutral, but that will probably fail inspection.....at least it would around here. You did a great job of keeping the install very clean and tidy, that's for sure. I don't do any residential electrical work, just electrical on diesel locomotives (actually I repair and calibrate welding machines currently) at work.
  3. ewdudley

    ewdudley Minister of Fire

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    Maybe it's OK if it's a legit three-wire 240 VAC circuit running power to a condensing unit or some such?
    ScotO likes this.
  4. ScotO

    ScotO Guest

    That very well could be.......again, I'm no expert on residential. What threw me off was the double pole breaker with that wire going into it. Would that be acceptable to have two double pole breakers dedicated to one circuit? Wouldn't a triple pole breaker be the norm for an application like that?
  5. Locust Post

    Locust Post Minister of Fire

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    Around here I do believe you can use a neutral for a 240 application as long as you mark it as he did to show it is a hot leg. I am not a certified electrician though so I could be wrong.
  6. fbelec

    fbelec Minister of Fire

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    if i see it right, you say it's a 60 amp sub panel. and you used copper wire which should be # 6 gauge. if i see right and the bottom pipe in the middle is where the feed comes in you should have a # 6 ground. from what i see it looks like a # 10 and yes i do see your grounding conductor which looks to me like a # 4 from a ground rod.
  7. jharkin

    jharkin Minister of Fire

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    Sounds right to me.

    Waiting to see what highbeam says, but my guess is its a 240v appliance that doesnt require neutral (ie pure 240, not a 240&120 mixed like a range or dryer). In that case you are allowed to use a 2 wire+ ground romex, the white lead is used for the second hot leg coded with black tape same way as you would for using white on a hot switch leg.

    My bet is that line feeds a 240 volt air compressor.
    Joful and ScotO like this.
  8. ScotO

    ScotO Guest

    That very well could be......either way, very nice looking install!
  9. jharkin

    jharkin Minister of Fire

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    EDIT to add: Im sure all of the below is there i just cant see it in the photos.....

    ---


    Actually I'm confused about the incoming connection. It looks like the feed from the main panel comes in at the top. you have heavy (looks like the proper #6) red and white hot wires to the 60 amp breaker. I also see a heavy gauge wire to the ground bus. Its hard to tell from the photos - where is the wire to the neutral bus bar?


    What I believe you need, and this is how Im doing my garage sub - is the feed from the main panel would usually be a 6/3 w/G as such:
    #6 insulated red - hot #1
    #6 insulated black - hot #2
    #6 insulated white - neutral
    #10 bare - ground

    the ground and neutral bars are isolated.

    IF this panel is in a detached building (and since you say shed I believe yes) from the main panel you also need an additional #6 ground going to a separate ground rod. So your neutral would have the one heavy white wire going back to main, and the ground bus would have 2 connections - #10 back to main and #6 to the local ground rod.
  10. jharkin

    jharkin Minister of Fire

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    Agree, nothing in my house is wired anywhere near that neat, not even the professional work.
  11. Highbeam

    Highbeam Minister of Fire

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    Yes, that is a 10/2 for a compressor. It feeds a 60 amp, 10HP rated, disconnect at the other end. It is a 240 volt load protected at 30 amps. You can use the black tape to code the white wire as a hot in this case.

    BTW, these discos are only like 5$ from home depot and are a great way to terminate a large connection for something like a water heater, boiler, compressor, or whatever.

    The other 10/2 that you see entering the panel is for my 30 amp RV plugs. In that case, I use a single pole breaker though so no need to code the white.
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  12. Highbeam

    Highbeam Minister of Fire

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    This is what I have. The feeders come in from below and if you look closely you can see the black, white, and red going left and the smaller ground heading to the right for the ground buss. Also out the bottom is the big, #6 or #4 even, braided ground to the pair of rods outside.

    The #6 neutral from the main goes to the top spot in the neutral buss. Since these feeders were the first to be landed on the panel, they are in the back.

    The panel is a 100 amp panel and uses the 100 amp main breaker as a disconnect but the feed from the main panel is protected with a 60 amp breaker.

    The other conduit heading out the top of the subpanel is for a boiler. It is 8 gauge thwn breakered at 50 amps. I did this in conuit so that in the future, should I put in a larger boiler along with a larger subpanel feed, I could pull a larger wire through the conduit. 50 amps means a 40 amp boiler for my slab heat which is smaller than most.
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  13. Highbeam

    Highbeam Minister of Fire

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    Yes, copper #6 THWN. The ground from the main is only #10 though. Why do you think it needs to be a #6 ground? I was told that you can downsize the ground between the sub and the main but the other three must be full size. Kinda like when you buy 6/3 romex and the ground is way smaller.
  14. Highbeam

    Highbeam Minister of Fire

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    There is one mistake though that it would have been hard for you folks to see. Turns out that you need to staple the romex within 12" of leaving the cabinet. So I need to add a block above the panel and staple.

    Attached Files:

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  15. jharkin

    jharkin Minister of Fire

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    Sounds like you got it all perfect HB - very nice work there!

    ETA - Sounds like you have quite a workshop. Feeling some major tool envy here :cool:
  16. semipro

    semipro Minister of Fire

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    I can't recall just why right now but I've found it handy to label the cables exiting the box with the corresponding breaker number.
    Saves having to remove the breaker cover and maybe shutting down the main when doing circuit mods maybe?
  17. Locust Post

    Locust Post Minister of Fire

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    Sounds like a winner.
  18. fbelec

    fbelec Minister of Fire

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    now i'll have to look it up. but anytime i did panel work the ground is #6 for a panel.
  19. Don2222

    Don2222 Minister of Fire

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  20. Highbeam

    Highbeam Minister of Fire

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    Thank you folks, this shop has become a hobby all its own. Never mind what I do in the shop.
  21. Don2222

    Don2222 Minister of Fire

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    Now, how about a Paint Booth, Blasting Cabinet and Soda Blaster?

    Harbor freight has them at some real nice prices!
  22. Highbeam

    Highbeam Minister of Fire

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    That 10/2 compressor circuit is for a 240 volt compressor that I do not yet own. Another "before I close the walls up" project will be running air lines, but get this, after the initial vertical chunk of black iron, I plan to switch to Pex water line for the air lines. Using a proper pex crimper is very easy and cheap compared to the sharkbites. Black iron is more expensive than pex and less than copper but with pex, no special skills are required.
  23. jharkin

    jharkin Minister of Fire

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    Have you thought about purpose made plastic air line systems, like Rapidair ? I was thinking about using that to pipe air from my garage to the basement when I ever get a big compressor...
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  24. ScotO

    ScotO Guest

    That's what I'm going to be running in my garage......I'll be running a line into the basement, and also one underground from my barn (where the compressor is located). That way, I'll have air in the basement, garage, and barn.......but all the noise will stay out in the barn!
  25. Locust Post

    Locust Post Minister of Fire

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    A very good friend of mine used standard cpvc water line for air line and never had a problem. I was sceptical when I saw it but that was in 1987 and it is still just fine. Just sayin'
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