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

AC\DC

Senior Member
Location
Florence,Oregon,Lane
Occupation
EC
well its not %$#bacwards if your correcting a violation that you are touching. You'r call either way. Just do it correctly and have owner pay. Will keep your name good and the people that complain about extra prices are customers you don't want.

P.S like your name- Gribble
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Seems bass-ackwards to add a whole new set of connections - one per every conductor, including EGCs - just to get around 312.5(c). I'm going to see if it can be grandfathered-in, this being a straight replacement.
Agree that adding extra connections would be a negative. Which is why my suggestions don't involve any extra splices. Nobody has commented on any of them specifically, so I don't know if any of them would be considered NEC compliant. Of course, what matters is what your AHJ would consider NEC compliant--Dennis's comment suggests 312.5(C) is routinely ignored in your area.

Cheers, Wayne
 

AC\DC

Senior Member
Location
Florence,Oregon,Lane
Occupation
EC
To each his own but how does installing a enclosure and securing each cable to it then run them up a conduit to that panel, safe on time or material. Then just running them up wall and securing them to panel if NMB is allowed outside for 6' like specified.

The way your proposed is not different than my first option were I mention transiting to Thwh to make NEC compliant. You just don't splice them and run them up conduit.

Seems a lot quicker to just to connect to panel.
Either your way or mine he still going to have to contact the cables to some type of enclosure so its not @#$bawards.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Agree that adding extra connections would be a negative. Which is why my suggestions don't involve any extra splices. Nobody has commented on any of them specifically, so I don't know if any of them would be considered NEC compliant. Of course, what matters is what your AHJ would consider NEC compliant--Dennis's comment suggests 312.5(C) is routinely ignored in your area.

Cheers, Wayne

That is correct. I would ask anyone to come up with a compliant way that doesn't have splices and doesn't make a mess out of the siding. We are talking an external panel with 30-40 circuits perhaps.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
The first idea wireway still doesn't stop splices because technically you cannot run nm cable thru the conduit on the exterior-- now NC allows it yes but suppose the wires are coming from a crawl area. How do the wires enter the wireway? You cannot drill 20 holes and bring the wires into it so how do you propose entering the wireway and be compliant-- forget NC rules.
 

Amps

Electrical Contractor
Location
New Jersey
Occupation
Electrical, Security, Networks and Everything Else.
Buy a Rubbermaid shed and cut the back out, screw it to the exterior over the panel area. Now its indoors! lol
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
The first idea wireway still doesn't stop splices because technically you cannot run nm cable thru the conduit on the exterior-- now NC allows it yes
Right, that would only work for NM in NC.

but suppose the wires are coming from a crawl area. How do the wires enter the wireway? You cannot drill 20 holes and bring the wires into it so how do you propose entering the wireway and be compliant-- forget NC rules.
Well, if it's 20 small NM cables, and clamps can only handle 2 cables each, then yes, I'm proposing drilling 10 holes in the junction box/enclosure/wireway/whatever, and one big hole to attach the large PVC nipple (< 24"). So if the existing PVC goes through the rimboard, the box needs to be recessed inside a joist bay, could be a bit difficult if the joists run parallel to the rimboard.

Each cable gets clamped to the box and then passes into the panel through the conduit nipple (< 24") to the panel. The PVC nipple is sized so that the conduit fill is no more than 60%, using the major diameter of each cable to calculate the equivalent circular area.

Of course, I also like the idea of one (or several) large screw mount cable ties inside the panel. Seems simple.

Cheers, Wayne
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Right, that would only work for NM in NC.


Well, if it's 20 small NM cables, and clamps can only handle 2 cables each, then yes, I'm proposing drilling 10 holes in the junction box/enclosure/wireway/whatever, and one big hole to attach the large PVC nipple (< 24"). So if the existing PVC goes through the rimboard, the box needs to be recessed inside a joist bay, could be a bit difficult if the joists run parallel to the rimboard.

Each cable gets clamped to the box and then passes into the panel through the conduit nipple (< 24") to the panel. The PVC nipple is sized so that the conduit fill is no more than 60%, using the major diameter of each cable to calculate the equivalent circular area.

Of course, I also like the idea of one (or several) large screw mount cable ties inside the panel. Seems simple.

Cheers, Wayne

Do you realize the mess you are making behind the wireway. That would be an incredible mess and then unless you are in NC the nm cannot pass thru into the panel because it is outside so you would technically have to splice every cable.

I hope you see that there is not a good way to do this and I have seen it done with pvc and nm coming out the bottom into a crawl a thousand times. I have never seen one issue with this install-- yes, it is not compliant but I fail to see the problem. This install was done long before I got here and that was back in 1978 so I have no issue with this not being safe.
 

Amps

Electrical Contractor
Location
New Jersey
Occupation
Electrical, Security, Networks and Everything Else.
Maybe this has been considered, sorry if it has, but is there any way the panel can be relocated indoors? A main outside and subpanel inside?
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Do you realize the mess you are making behind the wireway.
No, I don't see the problem. The wireway or junction box would be in the crawl space, there'd still just be a single 2" PVC conduit passing through the siding.

Outside NC you'd still need a solution for NM in exterior conduit. Lowering the panel so that the PVC can come into the back would be good, but if it has the meter, that may not be possible. But there are other options.

Cheers, Wayne
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I thought the wireway was under the panel. Have fun installing a wireway in a crawl space that is 3' high. Sure everything is doable but it gets ridiculous, IMO.

I thought about writing a proposal for this but I really doubt they would let it fly even with evidence that it is not an issue
 

RustyShackleford

Senior Member
Location
NC
I don't believe indoors is an option.

I suppose putting a box on the crawlspace end of the conduit could have the advantage of not having to worry about wire lengths in the new panel. I imagine I could even put a ground bar in the box and not have to run all the grounds into the panel - just a #4, that being the ground electrode size for 200amp service ? Reducing the number of wires going through the conduit by about 1/3. Could the same thing be done with the neutrals ?
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I imagine I could even put a ground bar in the box and not have to run all the grounds into the panel - just a #4, that being the ground electrode size for 200amp service ?
A shared EGC only need be large enough to suit the largest circuit's requirements; a #10 in most cases.

Reducing the number of wires going through the conduit by about 1/3. Could the same thing be done with the neutrals ?
You can combine circuit pairs into MWBCs, as long as you tie breaker pairs, but not one large neutral.
 

RustyShackleford

Senior Member
Location
NC
Thanks for the discussion. I'm gonna go with Dennis and assume what's there now - romex going through conduit, secured only by stapling in crawlspace right before it enters the conduit - will be acceptable to AHJ, confirmed by pre-job consult. I might try to upgrade the conduit to 2-1/2" though.
 

Rick 0920

Member
Location
Jacksonville, FL
Occupation
Electrical Instructor
I've had to remove the conduit before and install a "J" box where cables emerge from the building, the use THHN/THWN-2 in a new piece of conduit up to the panel per 300.9
 

RustyShackleford

Senior Member
Location
NC
I've had to remove the conduit before and install a "J" box where cables emerge from the building, the use THHN/THWN-2 in a new piece of conduit up to the panel per 300.9
Yeah, late to the party :) That's what's been said above is needed in order to be NEC-complaint. But fellow Tarheel Dennis, intimately familiar with our code variations, believes it'll probably fly without doing that (if I understand correctly), especially since it's a straight replacement, where, for example, upgrade to AFCI is not required.
 
Top