all branch circuits go into panel via 2" PVC, 310.15(B)(3)(a) issue ?

[RustyShackleford]

Another issue is space in the panel - for wire bending, add'l ground bar, and such. Check this screen-grab from the Siemens catalog. Note for the 30-space/48-circuit boxes, the "outside" version is 5" taller, whereas the "inside" versions fits 10 more "spaces" (5" vertically) into the same 30" height as the older-generation 20-space/40-circuit boxes. ( I'd be tempted to use the outside box even if this were an indoor situation).

Also tempted to put the new box "upside-down" so the ground bars are close to where the branch-circuit conductors enter. Assuming there are code-compliant ways to transition from the 2" or 2-1/2" PVC conduit to the hub cutout at the breaker end of the panel.

 

[Mr. Serious]

These hold three nmb cables http://www.aifittings.com/catalog/n...supports/cable-connectors-for-nm-se-cable/842

The linked page says "up to 2 NM cables at one time." Did it say 3 when you posted it earlier this month?

 

[AC\DC]

The linked page says "up to 2 NM cables at one time." Did it say 3 when you posted it earlier this month?

Weird I know they have one that does 3
Wrong link

Arlington | 842RH Product Information

NM cable connector zinc die-cast. 2 screw clamp type. Handles combinations of NM cable from #14 to #10. Up to 3 NM cables at one time. 3/4 Knockout. Also handles one 8/2, two 4/2 service cable. Robertson head screw

www.aifittings.com

 

[Amps]

Take a look at Arlington NM841-NM844
No screws or locknut. Saves time.

 

[wwhitney]

Take a look at Arlington NM841-NM844

Bad URL, your search terms were not embedded in the URL. Try these links, in increasing order of KO size, from 1/2" to 1-1/4":

Arlington | NM841 Product Information

Non-metallic Push-In connector utilizes a wedge push in design for a secure grip with a knockout size of 1/2 inch.

www.aifittings.com

Arlington | NM842 Product Information

Non-metallic Push-In connector utilizes a wedge push in design for a secure grip with a knockout size of 3/4 inch.

www.aifittings.com

Arlington | NM843 Product Information

Non-metallic Push-In connector utilizes a wedge push in design for a secure grip with a knockout size of 1 inch.

www.aifittings.com

Arlington | NM844 Product Information

Non-metallic Push-In connector utilizes a wedge push in design for a secure grip with a knockout size of 1-1/4 inch.

www.aifittings.com

Cheers, Wayne

 

[AC\DC]

I have used them, only problem with them is on 3r pvc box’s when I transition from nmb to thwn the boxes thinkness does not allow those to be used have to use 2 screws with long throats

 

[Amps]

That's a lot of splicing. Are you using wire nuts or wagos?

 

[AC\DC]

Wagos. Not to much splicing, only one,largest ground to panel.
Would rather not do it but we don’t have an allowance for nm outside.

 

[tortuga]

If your under the 2020 NEC you could add tiny section of cable tray in the crawl space. Per the new exception 2.
In reality the intent of 312.5(C) is to prevent someone from putting a close chase or PVC adapter in the panel and pulling all the romexes thru.
And then if there is a catastrophic bolted fault failure in the panel (typically a service) all that vaporized copper and aluminum jets into the hole.

Could it be also be argued that once the 2" PVC conduit run is over 24" long, and now your doing a chapter 9 fill calc and de-rating, its now the PVC 'wiring method' attaching to the 'cabinet' from the point of view of 312.5(C)? And since NC has that exemption your fine outdoors up to 6 feet or whatever.

 

[Strombea]

I don't think the securing is that necessary
334.30
(B) Unsupported Cables. Nonmetallic-sheathed cable shall be permitted to be unsupported where the cable:
(1)
Is fished between access points through concealed spaces in finished buildings or structures and supporting is impracticable.

always remember the guys writing all this code are not the brightest bulbs in the drawer, sometimes we have to use common sense. You'd be hard pressed to find a situation that this type of install has killed someone. At least your upgrading the panel, sometimes you can't fix everything.

 

[AC\DC]

You have to still secure it to the cabinet, or Am I miss reading what you meant

 

[Strombea]

I'm just saying, when it's a remodel situation, do the best you can within reason, when THHN enters a cabinet it is not secured. So even though it's written like that, sometimes it doesn't make sense. Obviously on a new install you would secure it. My inspectors here in Arizona have told me to just do the best you can, it's better than it was.

 

[Mr. Serious]

I like the idea of stripping back the NM, even though technically it's not allowed because that inner wire is "similar to THHN/THWN" but is not listed. Run all the NM circuits into a 12x12 junction box in the attic, strip everything back and put a ground bar in the box, and take a 2" PVC out the back, through the end wall of the house, and down into the side of the panel (with LBs at top and bottom). Run all circuit conductors and one main grounding wire down into the panel through the 2".

I like the idea, but I don't think I will try it and see what the inspector says. I'm on shaky ground in Tulsa because I've only done three jobs there, and two of them were managed by an acquaintance who doesn't have a license but was running the jobs under my license, and he screwed up the last one and I had to get it re-inspected after he fixed it.