Ask Me Help Desk

Ask Me Help Desk (https://www.askmehelpdesk.com/forum.php)
-   Electrical & Lighting (https://www.askmehelpdesk.com/forumdisplay.php?f=105)
-   -   Type of wire to use for a subpanel run to my basement (https://www.askmehelpdesk.com/showthread.php?t=321678)

  • Feb 24, 2009, 07:10 PM
    buddybartels
    Type of wire to use for a subpanel run to my basement
    Hi - I am running a 100 amp service/sub panel down to my basement and was planning on using #2 gauge wire for the run based on electrical guidelines. The line will run for about 30 feet on the outside of my garage in conduit and then feed into my basement for about a 40 foot run in the rafters to make it to my new 100 amp sub panel.
    I read that I can use aluminum outside in the conduit, but not in the basement? What if I ran conduit in the basement as well? Then could I use aluminum for the whole run or is that a hazard in any way?
    Any help would be greatly appreciated!

    Buddy
  • Feb 24, 2009, 07:28 PM
    stanfortyman
    Quote:
    Originally Posted by buddybartels View Post
    I read that I can use aluminum outside in the conduit, but not in the basement?
    Where did you read this incorrect information?
  • Feb 24, 2009, 07:57 PM
    buddybartels
    Quote:
    Originally Posted by stanfortyman View Post
    Where did you read this incorrect information?
    Well, the first place I read that was on a wire information chart at Menards (like Lowes/Home Depot). It stated that their #2 aluminum wire was for outdoor use only. Then I've also seen it in a forum that said it was a fire hazard to run aluminum inside.

    What are your thoughts? Can I use one type of wire to make this whole run outdoor through conduit and then inside through my basement to the subpanel?

    Thanks again.
  • Feb 24, 2009, 08:08 PM
    stanfortyman
    If the outside portion is just a sleeve for protection you can use NM cable or SER cable no problem.
  • Feb 24, 2009, 08:11 PM
    buddybartels
    Quote:
    Originally Posted by stanfortyman View Post
    If the outside portion is just a sleeve for protection you can use NM cable or SER cable no problem.
    Sorry to keep asking... so I can use NM or SER outside in a conduit for about 30 feet and then through my basement rafters about another 40 feet to get to my subpanel?
  • Feb 24, 2009, 08:13 PM
    stanfortyman
    Yes, you can use regular NM cable as long as the conduit is not underground. You can also use UF or SER cable.
  • Feb 24, 2009, 08:14 PM
    buddybartels
    Quote:
    Originally Posted by stanfortyman View Post
    Yes, you can use regular NM cable as long as the conduit is not underground. You can also use UF or SER cable.
    What about aluminum wiring? There is an aluminum 2/2/4 that is kind of bonded together that is marketed as a service entrance wiring that I've seen. Can this be used to make the entire run?
  • Feb 24, 2009, 08:45 PM
    stanfortyman
    No, that would be SEU. That only has three conductors. You need 2/2/2/4 SER cable.
  • Feb 24, 2009, 08:54 PM
    buddybartels
    Quote:
    Originally Posted by stanfortyman View Post
    No, that would be SEU. That only has three conductors. You need 2/2/2/4 SER cable.
    Why would I need 2 ground wires?
    Aside from that fact anyway, would I be able to run the aluminum the whole way... even indoor?

    Thanks for the help
  • Feb 24, 2009, 09:20 PM
    stanfortyman
    It is not two grounds. It is two hots, one neutral, and one ground.

    Yes, you can run the aluminum wire inside.
  • Feb 25, 2009, 06:54 AM
    buddybartels
    Quote:
    Originally Posted by stanfortyman View Post
    It is not two grounds. It is two hots, one neutral, and one ground.

    Yes, you can run the aluminum wire inside.
    I was looking at my 100 amp feeder sub panel though and there isn't a separate place to put the ground and neutral wires. Therefore, they would be doing the same thing so I figured it would be unnecessary. Am I missing something?

    Thanks for the help. One more question... does the aluminum 2-2-2-4 have to be inside conduit once in the basement up in the rafters?

    Thanks.
  • Feb 25, 2009, 07:02 AM
    donf

    A sub panel requires both a ground bus bar and a neutral bus bar. The neutral bus bar must be electrically isolated from the panel box and ground bus bar.

    Also, if the panel is located is a different building than the main panel, you must supply an equipment grounding conductor and one or more grounding electrodes.
  • Feb 25, 2009, 07:17 AM
    buddybartels
    Quote:
    Originally Posted by donf View Post
    A sub panel requires both a ground bus bar and a neutral bus bar. The neutral bus bar must be electrically isolated from the panel box and ground bus bar.

    Also, if the panel is located is a different building than the main panel, you must supply an equipment grounding conductor and one or more grounding electrodes.
    Thanks Don. Here is the web link to the subpanel I bought. Product Detail : HOM612L100F Load Center , 100A, Main Type: Fixed - Factory installed main lugs, 1-Phase - Schneider Electric
    On the info below it, it says grounding bar sold separately? Is that the ground bus bar you mentioned above?
    As far as your second comment, the panel is located in the basement and the main panel is in the garage. Technically, not a different building then, right?

    Thanks.
  • Feb 25, 2009, 01:43 PM
    stanfortyman
    In the MAIN panel the grounds and neutrals use the same bar(s). This is proper, but ONLY in the MAIN panel or disconnect.

    Yes, you need to keep the grounds and neutrals separate in the sub-panel.

    Your 100A main may not have holes big enough for the #2 neutral. You will most likely need an add-on lug to accept the #2. Get the brand and series of the panel you have and go to an electrical supply house. They will have what you need.
  • Feb 25, 2009, 01:47 PM
    Tev

    Yes, the ground bar you need is sold separately. Remember to remove the green screw that bonds the neutral bar when you are working on this.

    If your garage is attached then no, it is not a separate building so no additional ground rod is required.
  • Feb 25, 2009, 01:56 PM
    buddybartels
    Quote:
    Originally Posted by Tev View Post
    Yes, the ground bar you need is sold separately. Remember to remove the green screw that bonds the neutral bar when you are working on this.

    If your garage is attached then no, it is not a separate building so no additional ground rod is required.
    Awesome... found the ground bar at Lowe's today. I will plan on running SE 2-2-2-4 from a 100amp double pole breaker in my main panel. I'll run it in plastic conduit on the side of my garage / house to the point where I want it dropped in my basement. At the point where I drop into my basement, I will continue the same cable through the rafters to get to my 100amp sub panel. It that panel, I'll be sure the neutral bus bar is completely isolated from the separate ground bar.

    Just wanted to give a final rundown to make sure I wasn't missing something.
  • Feb 25, 2009, 02:18 PM
    KISS

    On the surface it appears as two grounds because two conductors are connected to the same bus in the main panel (USUALLY). One in the sub-panel ground and neutral remain separate.

    You sometimes need to purchase a ground lug kit and remove the neutral to ground bonding screw in the sub-panel. Grounds and neutrals MUST remain separate in the sub-panel.

    If the sub-panel is in a detached structure, you must install a ground rod.

    • All times are GMT -7. The time now is 03:50 AM.