Cabin circuits

[bluedog225]

Good afternoon and Merry Christmas.

I’m thinking through the details of wiring my workshop/cabin.

I’ve got a conex solar fed powerhouse that can deliver about 20,000 W continuous. More than I’ll ever need as a practical matter for my 25’ x 25’ three story workshop and cabin.

I was planning a 200 amp main panel in the conex and a subpanel in the workshop/cabin. Right now I’m running stuff on 12 AWG extension cords.

I’ve got closely placed LVL’s on the ceiling of the first floor. This is the workshop area. And this is where I want to locate my subpanel.

I’ve been doing a some of research and I think I understand where THHN is appropriate where romex is appropriate.

Getting from the workshop to the first floor kitchen. To avoid drilling a bunch of holes in the 12” oc LVL, I was going to run THHN in EMT from the subpanel along the wall and up through the ceiling into a storage room. At that point, I’ll put a large junction box. Not an LB. And then I was going to run romex from the junction box to my kitchen circuits.

That seems to avoid the issues of running unprotected romex along the wall or under the LVL’s. And I believe it’s inappropriate for me to just run the romex inside the EMT even if it’s inside.

There’s a similar plan for all of the circuits in terms of getting from the garage to the first floor.

Am I on the right track? And on the kitchen circuits in particular, is there any benefit to put in a load center with its own breakers in the storage room? I don’t know what the rules are on sub – sub panels. I could run a larger gauge wire to this load center and power all my 20 amp kitchen circuits off of it. And maybe there’s some advantage in terms of a centralized ground fault.

I’m new with this. Any thoughts appreciated. For what it’s worth, I’m out in the country on acreage. There won’t be a formal inspection, but I may hire somebody to come check my work at the end before I energize it. I plan to do everything in accordance with the NEC.

 

[75gmck25]

Since you are starting from scratch with electrical, try to keep the design simple and easy to maintain and troubleshoot.

Is this building already under construction? 12" spacing on LVLs is unusual, since you can spec them for standard 16" spacing and probably save money. I don't know the rules for putting holes through LVLs, but I'm sure there are manufacturer guidelines to ensure you don't cause any issues.

You can put Romex inside EMT or other conduit if you need it for physical protection. In the first floor shop you could drywall the ceiling and walls, and then run EMT on the surface - easy to maintain and modify. From there you could run one circuit up to the sub panel on the second floor, and run all the upper floors wiring with Romex from there.

I'm not aware of any special restrictions (other than normal code for a sub panel) on a sub-sub panel in the same building.

 

[dscheidt]

You can put Romex inside EMT or other conduit if you need it for physical protection.

You can, but you have to calculate conduit fill as if the romex is circular, and a single piece fills (or overfills) a conduit. So it really doesn’t make sense to do so, since you need to have boxes anyway. Just run individual conductors (thhn, etc), and switch to romex at the first box, which needs to be metal. The exception is short sections of conduit used as protection sleeve, but not part of a conduit system.

I’d run conduit to a junction box on the second floor, and romex from there. I would also put the box where I already wanted a device (or somewhere I could at least pretend I wanted a device), and use a big box, either a deep 4” square, or a 4 11/16 if you require the extra space. Fit a mudring to go to a single (or double) gang, and it will look like the other devices. Don’t forget to tie the romex grounds to the box.

I would also probably run those circuits as mwbc, splitting the neutral at the romex transition. But that’s not necessary, just more elegant.

 

[bluedog225]

Since you are starting from scratch with electrical, try to keep the design simple and easy to maintain and troubleshoot.

Is this building already under construction? 12" spacing on LVLs is unusual, since you can spec them for standard 16" spacing and probably save money. I don't know the rules for putting holes through LVLs, but I'm sure there are manufacturer guidelines to ensure you don't cause any issues.

You can put Romex inside EMT or other conduit if you need it for physical protection. In the first floor shop you could drywall the ceiling and walls, and then run EMT on the surface - easy to maintain and modify. From there you could run one circuit up to the sub panel on the second floor, and run all the upper floors wiring with Romex from there.

I'm not aware of any special restrictions (other than normal code for a sub panel) on a sub-sub panel in the same building.

It’s already dried in. I’m slowly finishing out the interior. Electric is on the list before it gets hot again so I can at least get a window unit and maybe mini splits. Since the garage wall is thicker than the top plate, I’ve got to get a little creative on how I get the power upstairs.

I didn’t know you could put romex inside EMT. Though I have plenty of thhn. And I’m going to run EMT for the garage circuits anyway.

Tnanks

 

[bluedog225]

You can, but you have to calculate conduit fill as if the romex is circular, and a single piece fills (or overfills) a conduit. So it really doesn’t make sense to do so, since you need to have boxes anyway. Just run individual conductors (thhn, etc), and switch to romex at the first box, which needs to be metal. The exception is short sections of conduit used as protection sleeve, but not part of a conduit system.

I’d run conduit to a junction box on the second floor, and romex from there. I would also put the box where I already wanted a device (or somewhere I could at least pretend I wanted a device), and use a big box, either a deep 4” square, or a 4 11/16 if you require the extra space. Fit a mudring to go to a single (or double) gang, and it will look like the other devices. Don’t forget to tie the romex grounds to the box.

I would also probably run those circuits as mwbc, splitting the neutral at the romex transition. But that’s not necessary, just more elegant.

Thanks. The mwbc looks interesting. A little above my pay grade but I think I understand it.