Inspectors / AHJ's do you enforce 312.5(C)?

tortuga

Senior Member
Greetings all, this question is mostly for inspectors and or AHJ's but all opinions are welcome,I frequently see PVC male adapters used as a chase nipple to get a ton of romex into the back of a 'trailer' style panel (loadcenter).
It has been discussed on here before that a residential 'loadcenter' falls under article 312.
And we all know later sections of the code may modify more general sections.

I am wondering why more inspectors don't enforce 312.5(C)? Its been in the code a while,
first added in the '75 Edition as 373-5(c).
In '99 they added the Exception but it would never cover most of the installations I see.
 

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LarryFine

Master Electrician Electric Contractor Richmond VA
I'll start with: How would you do it? I'd hate to try to make 20 or 30 separate holes in the rear of the cabinet.
 

tortuga

Senior Member
I'll start with: How would you do it? I'd hate to try to make 20 or 30 separate holes in the rear of the cabinet.
Well on a new home / small commercial it would be relatively easy to 'design' a better panel location, I do this pretty often; Meter/main outside loadcenter inside. On a residential panel change / service change it's more of a design challenge but usually full size outdoor loadcenter next to a meter.

I have not tried these yet but I see products are available:

https://www.bptfittings.com/store/mighty-merger-transition-fittings-3-4-multi-nm-connector.html
 

Dennis Alwon

Moderator
Staff member
I go with what Larry stated. Many moons ago Bob and I discussed this and I asked him how would you get 30-40 cables into the back of an outdoor panel. I got red tagged once on that and I had the state inspector call and straighten it out. There isn't a better way to do this other than set a jb on the other side. Seems totally unnecessary.

The nec does allow a piece of conduit going up a wall as a sleeve and allowing panel wires to enter thru the top as long as there is a bushing, the conduit is not longer than 10' and not shorter than 18"


312.5(C) Cables. Where cable is used, each cable shall be secured
to the cabinet, cutout box, or meter socket enclosure.
Exception: Cables with entirely nonmetallic sheaths shall be permitted to
enter the top of a surface-mounted enclosure through one or more
nonflexible raceways not less than 450 mm (18 in.) and not more than
3.0 m (10 ft) in length, provided all of the following conditions are
met:

(1) Each cable is fastened within 300 mm (12 in.), measured along
the sheath, of the outer end of the raceway.

(2) The raceway extends directly above the enclosure and does not
penetrate a structural ceiling.

(3) A fitting is provided on each end of the raceway to protect the
cable(s) from abrasion and the fittings remain accessible after
installation.

(4) The raceway is sealed or plugged at the outer end using approved
means so as to prevent access to the enclosure through the raceway.

(5) The cable sheath is continuous through the raceway and extends
into the enclosure beyond the fitting not less than 6 mm (1∕4 in.).

(6) The raceway is fastened at its outer end and at other points in
accordance with the applicable article.

(7) Where installed as conduit or tubing, the cable fill does not exceed
the amount that would be permitted for complete conduit or
tubing systems by Table 1 of Chapter 9 of this Code and all applicable
notes thereto.

Note 2 to the tables in Chapter 9 does not
apply to this condition.

Informational Note: See Table 1 in Chapter 9, including Note 9,
for allowable cable fill in circular raceways. See 310.15(B)(3)(a)
for required ampacity reductions for multiple cables installed in
a common raceway.
 

kwired

Electron manager
I agree that NEC does allow this when entering the top and you do everything else it mentions.

I realize it isn't real easy to enter multiple cables through the back of the cabinet, especially when cabinet is located on outdoor side of the wall, but NEC doesn't describe that sort of installation as an exception. I still say it is a violation unless you have local rule that otherwise allows it.


I have many times when relocating a panel to exterior surface ran raceways to attic/crawl spaces, or other uninhabited areas to juction boxes to convert to NM cable after that point. Usually have run 3/4 raceway and may need multiple raceways. If you run 2 inch expecting to get all 20 or 30 branch circuits in it, you need to adjust ampacity and can easily need 8 AWG for your 20 amp circuits.

Of course many guys that do almost exclusively residential work seem to think that raceways are not an option other than maybe for the service conductors.
 
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infinity

Moderator
Staff member
It's a violation plain and simple. What's wrong with making KO's for the cables and entering them the correct way with connectors?
 

Dennis Alwon

Moderator
Staff member
It is without a doubt a violation but one where inspectors have allowed because of the alternative.

Trevor look at the back of a panel.... many have 2 or 3 either 2 inch or 2.5" available for knockouts. Now if you could get 15 or more holes in the back of this WP panel think about the mess you would have in the band or siding where the wires must penetrate to get in the panel. It would be a mess and impossible to keep water from getting in there.

Trust me, we have dealt with this for years there is no good way to do it. The way it is shown in the photo is the lesser of 2 evils and, as stated, is unofficially allowed.

Some times the panel is up high and the ec's come out of the band with 2" lb's into the bottom of the panel. Well, nm is not allowed outside in a raceway in wet locations (NC allows up to 6' now)
but it was always allowed because the alternative was to run the home runs to a box then splice all the wires and use Thwn-2 into the panel----- That's a worse situation, IMO.

NM has been in vertical runs of conduit below a panel for 50 years and I have never seen any issues with the wire. Yes it is not compliant. Those of you who believe you can make this situation legal and not bastardize the siding are surely mistaken unless the wiring comes out below the panel and do as I stated with a box-- go ahead make 100 splices-- that would be insane.

Where the holes penetrate the panel in the picture there should be some caulking in the conduit to stop air flow to avoid condensation
 

K8MHZ

Senior Member
Typically these installs are all romex behind the panel, they often enter thru a 2" PVC box adapter, its pretty much like doing this but with a chase nipple or conduit adapter. No conduit it attached typically. I see panels like this very often.
In reference to the OP's pic, shouldn't the sheath enter the box? As per 312.5(C)5
 

construct

Senior Member
It's a violation plain and simple.
I agree, and with the others that stated it is a violation. But due to it bordering on impractical, I have allowed it. Am I supposed to? No, because we haven't amended the code. I have just always considered it a judgement call. ;)
 

hbiss

EC, Westchester, New York NEC: 2014
I agree, and with the others that stated it is a violation. But due to it bordering on impractical, I have allowed it. Am I supposed to? No, because we haven't amended the code. I have just always considered it a judgement call. ;)
Right, the code should be amended to PROHIBIT panels on the outside of houses to begin with! That will take care of that problem and a lot of others. :rant:

-Hal
 

Coppersmith

Senior Member
Right, the code should be amended to PROHIBIT panels on the outside of houses to begin with! That will take care of that problem and a lot of others. :rant:

-Hal
Many small older houses that started out with a tiny (4) fuse panel have no room anywhere inside the house for a breaker panel. The only reasonable solution is an outdoor panel. There is nothing wrong with outdoor panels. There are tons of them here. I have to repair them no more often than indoor panels. There is an occasional rusted out bottom, but not very often. The worst part of outdoor panels is it always seems to rain when it comes time to install a new breaker.
 

tortuga

Senior Member
Well I did a little digging on this as I am going to teach it in a class, and there is a bone yard of dead proposals trying to amend this going back decades.

Someone named Dennis Alwon submitted a small change to clarify 312.5(C) Exception (g) for the 2014 And it seemed to get quite the debate going in CMP 9 in the “Explanation of Negative” longtime CMP 9 member and author Frederic P. Hartwell comments on 312.5(C) Exception as

“one of the most surprisingly controversial, passionately debated, and

exhaustively studied topics in the history of CMP 9”
The read thru the dead proposals and rejections is pretty convincing. Looks like CMP9 thinks its an enormous issue because most of these panels are services and allot more can go wrong in them than a standard junction box.
 

hbiss

EC, Westchester, New York NEC: 2014
Many small older houses that started out with a tiny (4) fuse panel have no room anywhere inside the house for a breaker panel. The only reasonable solution is an outdoor panel. There is nothing wrong with outdoor panels. There are tons of them here. I have to repair them no more often than indoor panels. There is an occasional rusted out bottom, but not very often. The worst part of outdoor panels is it always seems to rain when it comes time to install a new breaker.
If you have a service change or upgrade on an existing house there is nothing you can usually economically do but keep the location. That picture in the OP however appears to be new construction. I can't believe the designer or builder of a new house can't provide a suitable location for the panel indoors. So I can only assume that they are ignorant or just don't care.

Another issue with outdoor locations is that we now have to use AFCI and GFI breakers containing electronics. Old panels with conventional breakers may have appeared to last but installing them outdoors now, when there is no good reason, is asking for problems.

-Hal
 

electrofelon

Senior Member
Right, the code should be amended to PROHIBIT panels on the outside of houses to begin with! That will take care of that problem and a lot of others. :rant:

-Hal
Considering that panelboards in 3R cabinets are quite common and frequently used in general, how exactly would you propose going about prohibiting them at dwelling units?
 

infinity

Moderator
Staff member
I agree, and with the others that stated it is a violation. But due to it bordering on impractical, I have allowed it. Am I supposed to? No, because we haven't amended the code. I have just always considered it a judgement call. ;)
But making the proper KO's is not impossible therefore your judgement call amounts to you enforcing your own code. ;)
 
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