[ktulu]

I have added on to my home and I orginallyplanned on running conduit through the slab and up an interior wall to feed a subpanel which will service the addition. Something happened (lost my mind) during the planning and I decided to just put an external sub panel on the outside of the addition and feed it from the main panel which is mounted about 10ft away on the outside of the exisintg house. Well now I am think I want the sub panel back inside and was wondering what the best way would be to feed the panel? Can I run my feed in conduit under the ground and then use a long sweep to come up from the ground and another sweep to go into the addition. The addition is bricked so I will have to make a hole and I assume I can get a flange to seal it off. THe slab is above grade so there is no way to bury the conduit compeltely. Is this best or should I just put the panel outside? I like the idea of the interal panel because they are cheaper and at this point I like cheap!! :o Plus it is looking crowded out there already and I plan on upgrading to 320A which will add at least one more panel.

Thanks in advance!

By the way I started wiring the inside today and I am starting to understand why I can't get an electrician out here. Drilling all these holes in the studs is boring and I can't even imagine how funky I would be after doing it all day in the summer!:eek:

[tkrussell]

As you know already, glad you checked into it, that an outdoor panel itself is much more costly than an interior pannel, since an outdoor panel is rated to be Rain Tight, or called NEMA 3R and an interior panel is rated NEMA 1.

Having the panel outdoor may be easier to feed , but you also need to consider all the new branch circuit cables, and any it the future, how to get these cables to the panel.

I think if it is at all possible, to get the panel inside will be much better for many reasons.

Yes you can drop down from the meter/disconnect with conduit, PVC Schedule 40 is best, have the conduit below grade, and rise up at the panel location. The conduit below grade will need to be at least 18" below grade, with a "Electric" warning tape 6-12 inches below grade the entire length of conduit.

If you are in an area that the ground freezes, then a PVC expansion coupling will need to be install in each riser.

Where the conduit rises up outdoor at the panel location or where the conduit needs to enter back into the building, drill a a hole 1/8" larger than the conduit, so if this is a 100 amp panel, then you will be using 1-1/4" PVC.

Electrical conduit is called out by the internal diameter, so 1-1/4" plus the wall of the conduit, the O.D. is about 1-1/2", a 1-3/4" hole should be fine.

I added a picture of the 90 degree fitting any electrician would use, called in the trade an LB, short for 90 Deg Ell / Bottom.

Oh , the conduit entrance is even a bit larger O.D. so a hole a bit larger than the O.D of the LB conduit entrance will be needed, so about 2", but measure the O.D. to be sure.

Some fittings and info can be found at:
http://www.carlon.com/Master%20Catal..._40_and_80.pdf

Once the LB is set in place permanently, you can caulk around the conduit as it enters the building.

Another task that must be done, whenever a conduit passes form one atmosphere to another, the conduit should be sealed to prevent condensation from forming, so we use a caulk/putty called Duct Seal to seal the inside of the conduit after the wires are pulled.

Hope this helps, get back if you have any other questions.

[ktulu]

Thanks TK that all makes sense. I will be feeding a 200Amp panel so would I need 2" conduit? It seems to me I was going to need to run 2/0 from the main. The panels are about 20 ft apart including the distance needed to go underground and back up into the panel. Also does the LB need to be at the same height of the panel or can I come 2 ft above grade and in to the building then run the wire in the wall and up into the bottom of the panel?

I'm in Arkansas. We don't have the freezing like you are used to:(

[tkrussell]

Correct, a 200 amp feeder, for residential only, can be not smaller that #2/0 copper, try to find XHHW insulation, otherwire, use THHN/THWN. Since the wire will be outdoor, any insulation must be Wet Location rated, and the W in both I mention means that they are rated to be wet.

Sure you can enter 2 foot above grade, just the conduit will need to be in the wall, and since the wall is probably only 6" thick, you will need to use two LB fittings back to back so to speak, just be sure the inside LB is not covered or buried, the removable cover must be accessible.

Would be better if you rise up and enter directly into the rear of the panel, I am guessing you don't want to see that much exposed conduit on the face of the brick wall, which is understandable.

Check with loal codes that expansion couplings are not needed , just to be sure. Would really be not so good to have it all put together and find out you need them.

[ktulu]

Thanks so much for all the great answers you give on this site. There is a lot of great info here.

Just to verify on the inside LB. The brick is just a veneer and the wall behind it is a 2x6 stud wall which will be drywalled. Is it still necessary to use a LB on the inside and if so does it matter that it will be behind the sheetrock? Just want to make sure I stay in code.

Thanks and Happy New Year!(Almost)

[tkrussell]

How else do you plan to go 90 deg up one inside the wall without using an LB inside?