Please help with wiring questions

[darkfader]

I have been trying to study everything I need to know in order to feed power to my new shop but with all the info, my head is spinning. I’m hoping some experts can lend a hand. I will attempt to be as specific as possible here.

I have 200 amp service with a Square D Homeline panel in my home. The wall where my main panel is, is not yet drywalled. I would prefer not to need conduit inside either structure, and do not want to splice the feeder.

Can I simply come from the main, through the wall of the house directly into conduit, down into the ground, then a 90 toward the shop, straight run of conduit less than 20’ to the back wall of the shop, another 90 up the wall of the shop and through the wall to the Square D 100 amp sub panel?

Will this wire coupled with a 90amp CB in the main allow me to accomplish all of this correctly and safely?

https://www.wireandcableyourway.com/4-3c-thhn-pvc-tray-cable-with-ground.html

Greatly appreciate the help

 

[pattenp]

Nope. You either need to have conduit panel to panel or do splicing changing wire types.

I don't think that tray cable can be run in a residential use without using a raceway.

 

[ard]

Nope. You either need to have conduit panel to panel or do splicing changing wire types.

I don't think that tray cable can be run in a residential use without using a raceway.

What cable should OP select so he can transition between conduit outside/underground and nothing inside??

Anything?

 

[Moto]

Yes, the conduit can go through the wall and directly into the panel at each end.

With conduit, individual conductors are used (as opposed to a cable with the conductors bundled together). eg: https://www.wireandcableyourway.com/THHN-THWN/

 

[wyliesdiesels]

What cable should OP select so he can transition between conduit outside/underground and nothing inside??

Anything?

The only cable thats possible with is UF-b which is a pain to pull in conduit.

OP needs to give up on either no conduit or no splices.

 

[darkfader]

Ok I appreciate the help. One more question, if I were to use the individual conductor THHN/THWN linked above, would I still need the conduit panel to panel or could the conduit terminate at the wall? Thanks again for the help

 

[maxpat82]

individual conductor need conduit pannel to pannel.

 

[darkfader]

Ok thanks. I guess I’ll just figure out a way to do the conduit panel to panel. Garage side will be easy, house side will be a challenge.

 

[pattenp]

When it's difficult to run conduit inside to panels use a junction box at the entry point to the structure and do splices to transition to SER for the run inside. SER uses the same install methods as NM-b.

 

[Crazyjake8493]

Any reason for not wanting to splice? It's done all the time, no issues if done properly. And the SER would be easier to run indoors.

 

[75gmck25]

I ran 2-2-2-4 AL SER from my QO main panel to a junction box on the outside wall, then transitioned to dual-rated MHF, which I ran through conduit from the junction box to the sub-panel in the garage. I had an LB on each end where the conduit came up out of the ground, and another LB inside the garage after it came through the wall and fed up to the panel. Pulling MHF was easy through 2" conduit.

I had to use conduit inside the garage because it has brick walls and the wiring needed physical protection. I could have run the conduit all the way up the wall outside and then gone directly into the back of the sub-panel, but it was less visible outside if I came through the wall at about 10" up and then turned 90 degrees inside with the LB, and came up into the bottom of the sub-panel.

The insulated connectors for the 2 gauge wire splice were kind of expensive (I used these https://www.amazon.com/gp/product/B00UKG8DNU/?tag=atomicindus08-20), and the junction box at the house was large because I used 2" conduit (required a 12"x 12" box). However, overall it was a straight-forward installation.

FYI - The wiring I installed could handle 90 amps, but I used a 60 amp breaker at the main because it was in stock at HD, and relatively cheap. I used a 24 circuit, 100 amp sub-panel in the garage just to get more spaces. However, I may never need to go to more than 60 amps and about 8 circuits.

Bruce

 

[darkfader]

Thanks for all the suggestions gents.

I guess I wanted to use the copper because I was under the impression that it would be easier to work with than the aluminum. Since my run is rather short, the added expense wasn’t really an issue. I need less than 30 total feet. I also thought I could use a smaller gauge wire if I went with Cu.

I didn’t want to splice just for less connections. Before doing my research I figured it was simple to just come out of the main panel, go through the wall, into conduit, back through the shop wall, and into the sub panel.

I called the local electric supply place today, and he suggested 2-2-4-6 MHF for the project. I had already read that a smaller neutral may not be desirable while still acceptable.

If I need conduit from panel to panel, then I’ll just have to make it happen. With that said, can I use the THHN/THWN individual conductor linked in post #4 above? And would I want 4AWG for hots and neutral and 6AWG for the ground? Then use a 90amp CB in the main?

Really apologize for all the questions, but this got a lot more complicated than I thought. Haha

 

[pattenp]

Yes you can use THHN linked above. #4 copper is good for 85A but can be protected by a 90A breaker.

 

[Moto]

I didn’t want to splice just for less connections. Before doing my research I figured it was simple to just come out of the main panel, go through the wall, into conduit, back through the shop wall, and into the sub panel.

What I'm picturing is that the conduit comes out of the ground, up the side of your house, into an LB fitting to make the 90 degree turn, then there is a short length of conduit going through the wall and in through the back of your panel.

That's the simple way to do it, no splices required.

But maybe I'm misunderstanding your situation.

 

[darkfader]

Yes you can use THHN linked above. #4 copper is good for 85A but can be protected by a 90A breaker.

Thanks!

What I'm picturing is that the conduit comes out of the ground, up the side of your house, into an LB fitting to make the 90 degree turn, then there is a short length of conduit going through the wall and in through the back of your panel.

That's the simple way to do it, no splices required.

But maybe I'm misunderstanding your situation.

Nope, you got it. That’s exactly how I’ll have to do it. I think I’ve got a good plan now. Thank you guys very much.

 

[ard]

Ok thanks. I guess I’ll just figure out a way to do the conduit panel to panel. Garage side will be easy, house side will be a challenge.

So just do one splice on the house end.... You can get a nice clean shot into the garage, take it.

Then you just have the house side- one nice big box, easy splice, done!


Although you say your wall isnt sheetrocked at the main panel...gotta think you could get it to work. Maybe a picture?

 

[darkfader]

Ok I haven’t been home all week and I actually forgot that my outdoor main disconnect has spaces for 4 single pole breakers. Is there any reason why I can’t wire directly into this with my feeder? I attached a photo. Would my ground and neutral just go into the same bar and then unbind the neutral in the sub panel just like normal? Same wire as stated above, conduit box to box. If this is ok, it’ll make the connection 99% easier.

 

[wyliesdiesels]

Yeah looks like you have 4 spaces.

I highly doubt those lugs are rated for 2 wires though...

 

[darkfader]

That second set of cables goes out to the shed. I can move those down to another breaker and just use all 4 spaces.

 

[Moto]

One of the wires appears to have some damaged insulation.

Also, you could do with a bushing on that conduit.