Conduit question

[Toadmanor]

If you use setting-type joint compound, you can be done in an evening, although you should probably wait overnight before painting.

I agree that opening and reclosing a wall is not that hard. If you are careful, you can begin/end your strip at the midpoint of joists and then you only need a piece or two of strapping to span the joists.

So, it looks like I was all set to "open the wall" and then I read this regarding "strapping". My intent was to drill holes through the studs and then run the romex through the holes.

What is this about strapping?

 

[mongo]

So, it looks like I was all set to "open the wall" and then I read this regarding "strapping". My intent was to drill holes through the studs and then run the romex through the holes.

What is this about strapping?

A chunk of wood you place behind the drywall to support the cut. Basically, the horizontal strip you cut out ends between the vertical studs. You cut a piece of plywood/osb/2x that spans the hole and align it so it is partly behind the remaining drywall. Screw through the drywall into it to hold it in place. Then put the piece of drywall you removed back. Now screw the ends into the wood and screw into the studs to secure the drywall strip. If you cut the wood long and place some poster board on the ends, when the screw around the cut, it will create a depression at the joint which aids in getting the joint flatter.


Finish with tap and mud.

Alternative is to end the strip on a stud for support.

A magnet will let you find the original screws. (Remove or align strip to avoid them)

If the drywall is glued to the studs, it will be more of a pain to remove the strip.

 

[sootless]

3 gauge romex (NM cable) is *not* rated to 100 amps. It is only rated to 85 amps at the 60c insulation rating (which you are required to use the 60c column for romex). 3 gauge in conduit can use the 75c column which *is* rated to 100a.

The NEC is already very conservative. I have no issues worrying about the safety of an install if done strictly to NEC requirements. I use 6 AWG in EMT conduit and I have never felt the conduit being warm.

I am very hesitant to make the argument about loss being lower to the point where it pays for larger gauge wire. It depends on a LOT of factors. If you spend $800 a year on power AND you can make the argument that you get 1% *less* loss with larger wire (which I question for most installs if that is feasible) then that is only $8 a year. If you spend $100 more in wire, that is a pretty long payback (not even factoring in time value of money).

Now with that being said, I often am a fan of increasing wire sizes for future proofing and for the other reasons listed above, but I don't think it is necessary for safety and I am not sure about the ROI on the wire upsizing just for that reason.

Thanks for your feedback. That is useful information. I am doing an install soon and deciding between 6/3 and 3/3. The additional details you have provided helps.