Porch wiring

[jpcjguy]

Wanted to check with the group on my thoughts of wiring for my screen porch.
The main panel is on the end wall of the attached garage and I already have conduit going from a junction box outside on the opposite side of the main panels that was put in place for the detached garage. There is an empty 1" and an empty 2" that curves around to the crawlspace under the bay window.
My plan is to use THWN in the conduit from that large junction box in the pic to under the crawlspace.
The red lines in the pic are what I would use THWN (in conduit) with the blue boxes as junction points. (this is all under the crawlspace)

There are 2 conduit stubs under the stamped concrete that I will continue with THWN. The small yellow boxes are outlets on the "outside" wall. The wall height is yet to be determined but is represented by the blue line. It will go around the entire porch (excluding doorways obviously). Thinking anywhere from 12"-36" high and be completely enclosed.
So where the wire comes out of the concrete stub(points "X" and "Y") into the first outlet, I will transition to UF-B within the wall as I go to the other outlets(Discussion with inspector said that would be fine)

The green wire is all under the house and directly into what will be a solid wall all the way up and I was told that could be NM-B.

That all being said - I was going to user 12 gauge wire everywhere - but considering I would around 60 feet from the main panel to the first outlet, I was thinking of moving to 10 gauge for all the red lines? or at least from the panel to the blue junction boxes? Or overkill?

 

[mm08822]

12 is plenty.

 

[mike93lx]

What would you ever run out there that would draw near 20a?

I'd also run 12. 10 is a waste

 

[jpcjguy]

What would you ever run out there that would draw near 20a?

I'd also run 12. 10 is a waste

Would not surprise me if my wife or daughter dragged a space heater out there on a cool day!

 

[mike93lx]

Would not surprise me if my wife or daughter dragged a space heater out there on a cool day!

Same here.

But a 120v space heater won't be 20a anyways

 

[jpcjguy]

True - wanted to cover my bases with voltage drop considering the overall length of the run…

 

[mike93lx]

True - wanted to cover my bases with voltage drop considering the overall length of the run…

60 feet is fine

Voltage drop is a function of distance and current draw. If you never actually pull 20a on those circuits, the drop won't be a problem

 

[jpcjguy]

Circling back on this - since inspector said I could use UF-B in the conduit, I was originally just thinking the conduit under the stamped from under the house to the porch and lower outlets. I guess nothing prevents me from using UF-B from the panel in the house, through the wall into the large junction box outside and then down the 1" PVC to under the house , right? (See pics of porch with pvc stubs circled and path to under house and pic of junction box with conduit path to under house)
That is a lot cheaper than 3 100ft rolls of THWN at $135 a roll!

2nd question - when I come out of the PVC on the porch with the UF-B wire, since it will be in an "enclosed box" do I need to have the PVC screwed/attached to the first electrical box? Especially when the rest of the run to the other boxes down the wall will be just UF-B wire "free floating"? I did a quick mock up of the stub and a 90 degree to the first box (the stub will be cut down considerably since the "box" will probably be 10-12" high). Can I have the UF-B wire just come out of the PVC (the 90 degree) free?

 

[dave*99]

That is a lot cheaper than 3 100ft rolls of THWN at $135 a roll!

I’m not sure how much wire you need but that price gets you 3 conductors

 

[jpcjguy]

I’m not sure how much wire you need but that price gets you 3 conductors

Interesting - did not see that. I shop at Lowes mainly and they only have that in 350ft roll - way more than I need.(100 ft of each color)
I already have a bunch of UF-B and the inspector confirmed I can use UF from the inside panel - through the wall (3 ft of wall) and through the outdoor (wall mounted) junction box to under the house (crawlspace) where I will branch off accordingly... so no need for THWN!
But thanks for pointing that out - usually I find HD and Lowes has similar stock....

 

[billconner]

The conduit is just for physical protection. I guess you are all pretty low and exposed - not over 8' above floor - so within their rights to require it protected.

Were I doing it, if exposed as I think, Is do all conduit. I prefer EMT and skip the ground but it may be moist or get wet enough you want PVC. I just prefer individual conductors in pipe. Plus you can get a lot more in 1/2" than probably just 1 UF-b. But it's a personal preference now and I have the benders and such.

 

[jpcjguy]

The conduit is just for physical protection. I guess you are all pretty low and exposed - not over 8' above floor - so within their rights to require it protected.

Were I doing it, if exposed as I think, Is do all conduit. I prefer EMT and skip the ground but it may be moist or get wet enough you want PVC. I just prefer individual conductors in pipe. Plus you can get a lot more in 1/2" than probably just 1 UF-b. But it's a personal preference now and I have the benders and such.

Thanks for the feedback - sorry if I was not clear - the conduit stub and wiring will all be enclosed in a 12" high "box" between the posts.
I found an image online that is similar - about half the height and the outlets horizontal, but will be fully enclosed. See attached - the gray conduit and the blue line represents the UF-B wire.

 

[billconner]

Thanks for the feedback - sorry if I was not clear - the conduit stub and wiring will all be enclosed in a 12" high "box" between the posts.
I found an image online that is similar - about half the height and the outlets horizontal, but will be fully enclosed. See attached - the gray conduit and the blue line represents the UF-B wire.

Well then if enclosed just UF-B or even NM-B, at least around here.

The only reason I know to put UF-B or NM- B in conduit is physical protection. If it's "enclosed", even if an exterior porch, not necessary - again - according to electrical inspector around here.