Announcement Announcement Module
Collapse
No announcement yet.
Protecting 6-3 run to sub-panel Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • Protecting 6-3 run to sub-panel

    I am running a 6-3 feeder cable through my basement from one end to the other. One area is open ceiling (2x8's exposed), another area is closed drywall ceiling (luckily going the same direction as the joists), and a third area I want to go through is a bulk-head that encloses the cold air return for my furnace.

    I know I've got to go through the joists (holes 1.5" from edge) or stapled if running in parallel in the open ceiling area, my question is about the parts that are drywall enclosed. I know I need to protect the feeder cable it if I can't keep it away from the drywall, question is what is sufficient protection? Is there some kind of flexible conduit that I can use that will withstand penetration from a nail or screw? I have a total of about 70 feet through the basement and only some of it needs armor so I didn't buy armored cable for cost reasons.

    Andrew

  • #2
    Re: Protecting 6-3 run to sub-panel

    Originally posted by athuswal View Post
    I am running a 6-3 feeder cable through my basement from one end to the other. One area is open ceiling (2x8's exposed), another area is closed drywall ceiling (luckily going the same direction as the joists), and a third area I want to go through is a bulk-head that encloses the cold air return for my furnace.

    I know I've got to go through the joists (holes 1.5" from edge) or stapled if running in parallel in the open ceiling area, my question is about the parts that are drywall enclosed. I know I need to protect the feeder cable it if I can't keep it away from the drywall, question is what is sufficient protection? Is there some kind of flexible conduit that I can use that will withstand penetration from a nail or screw? I have a total of about 70 feet through the basement and only some of it needs armor so I didn't buy armored cable for cost reasons.

    Andrew
    You don't drill through joists. You only drill through studs for electrical. The drywall is already in place so you are running through 'old work' you should make your best effort to keep it off the drywall but it is not necessary. In new work the wire must be 1.5 inches from any drywalled surface because they anticipate drywaller's hitting it if it is too close.

    When running wires through a basement it should follow the sill, or be between joists. Do not run across joists in an unfinished area. (concept is the wire should never be a a place that is easy to put a clothes hanger on.

    Comment


    • #3
      Re: Protecting 6-3 run to sub-panel

      Drilling through joists is done in basements in Canada and based on the one US reference I have it appears to be done in the States as well. I can't run along the sill because it's not accessible and if I could get to it there would be no place to put the wire because the sill is filled with insulation and then covered with vapor barrier.

      Comment


      • #4
        Re: Protecting 6-3 run to sub-panel

        Yes you can drill through joists. There is a proviso though the hole has to be 1 1/4 inches above the bottom of the joist.

        But you said it was 6-3 this can be strapped to the bottom of the joist the run will go faster that having to drill through a bunch of joist.. The key to running NM cable is to protect it from physical damage.

        But you already know that. Since the Sub-panel is on the same premises you should be running 6-4 and separate the neutral and ground. The grounding conductor is attached to the box and the neutral is 'floated' and no grounding conductors are tied to the neutral.

        If you are running this cable behind the covered wall and you can not maintain the 1 1/4 clearance then Nail Plates should be used to protect the cable.

        Comment


        • #5
          Re: Protecting 6-3 run to sub-panel

          Hi MotorT,

          Thanks for your feedback. I think we need to align our terminology which I think is different because of geography. When I talk of 6-3 cable it refers to 3 sheathed conductors (Black, White, Red) and a bare copper ground wire for a total of 4 conductors. I don't particularly like this terminology because I think it is confusing but I'm used to it. So when you said 6-4 in your post I think you meant the same thing I am talking about.

          I need to ask you a question that you can probably help me with since you are a professional in this field. I have recently learned that we are not supposed to put NM cable inside conduit. Here is my problem. I want to do about a 90 foot run from my basement panel to the subpanel in the garage but I want to shield the cable as it runs through a 15 foot bulk head in my basement ceiling. When the cable gets into the attached garage I want to protect it because it will run on an inside (the garage) wall for about 15 feet. So, from panel to subpanel I only need to shield about 30 feet of the run so using BX (armored cable) is over kill and costly. Do you see any issues with me using NM 6-3 and putting it through conduit for two 15 foot sections of the run? I can oversize the conduit if there are concerns about the cable heating up.

          Andrew
          P.S. I know the rule about running through existing work and how it's not necessary to shield it, sort of a best effort thing, but I see that as a hazard and am determined to do what I can to protect the cable and comply with the code.

          Comment


          • #6
            Re: Protecting 6-3 run to sub-panel

            If I understan you correctly, this is what is OK for you to do. You can strap the 6-3 to the underside of the joists in that part of the room, when you hit the sheetrocked area you can "fish" the wire through the joist and it could lay on the sheet rock, be sure to fasten it good before it enters and when it exits. It is allowed to fish wire through fisnished areas with no supports, when you hit the garage and you want to protect the wire from damage, the code procvides you may sleeve NM with conduit for protection purposes. The hitch here is that you claim the wire will be in a plenum that has somewthing to do with the heating system, then the wire should be plenum rated if that is the case. Lou

            Comment


            • #7
              Re: Protecting 6-3 run to sub-panel

              Thanks Lou. The wire is not going inside the plenum but beside the plenum and inside the same bulkhead (drywall and 2x2's) that contains the plenum. I know I'm allowed to fish and through unprotected but I'd like to know if I can protect the feeder by running it through a piece of conduit that I want to slide into the bulkhead. I just have have this discomfort putting a 60Amp cable unprotected into a bulkhead.

              Comment

              Working...
              X