Resi panel has all branch circuit entering through 1 MA

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McLintock

Senior Member
Location
USA
Occupation
Electrician
Yes, just as improperly failing something does not make it non-compliant.

I am just saying if you go 100% by code you will find a violation almost every time on any given job, no matter who did the work


“ shoot low boys their riding shetland ponies”
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I am just saying if you go 100% by code you will find a violation almost every time on any given job, no matter who did the work
I disagree, for those who know the code and install per the code their installations will be 100% code complaint. It's the guys who don't know the code who install violations everyday.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
Trevor we don't install outdoor panels except as a main disconnect. This was an old method many used, I did also, but the only time it is an issue for us is when we change a service that was done this way.

Imo, putting 2- 2" pvc connectors or couplings is the best install for these panels although it is not compliant.

It has been done all over the country and I have never heard of an issue with the install.
Wow! really? "it's not compliant,,,,BUT,,,,"
have you stopped to consider 2 things, Maybe the CMP has access to statistics of failures that you may not see and do you go to all the buildings that have had fires to see what does and doesn't work?
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Wow! really? "it's not compliant,,,,BUT,,,,"
have you stopped to consider 2 things, Maybe the CMP has access to statistics of failures that you may not see and do you go to all the buildings that have had fires to see what does and doesn't work?
You might be right maybe they have information that will say that it's unsafe but if you look at the photo #2 in post #15 what could possible go wrong with that installation which would make it a hazard? :unsure:
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
You might be right maybe they have information that will say that it's unsafe but if you look at the photo #2 in post #15 what could possible go wrong with that installation which would make it a hazard? :unsure:
That is a slippery slope to step onto. If we apply all code requirements to the barometer of "what could go wrong?" we are limiting the installation to our own experience and not the requirements of the code. While I do not always understand why a specific requirement is in the code, that does not mean it is not enforceable or without reason.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
That is a slippery slope to step onto. If we apply all code requirements to the barometer of "what could go wrong?" we are limiting the installation to our own experience and not the requirements of the code. While I do not always understand why a specific requirement is in the code, that does not mean it is not enforceable or without reason.

For me if I'm inspecting a job and the photo in post #15 is what I see on the job-site the installer will be ripping it out and doing it correctly according to the NEC. I know that this is the SOP in some locales I just wonder why that is when it is clearly prohibited by the NEC.

And if installing separate NM connectors into the back of an outdoor panel is problematic then don't install the panel outdoors. Seems like a no brainer to me, if you cannot install it outdoors without a violation then don't install it there in the first place.
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
Let’s just say you are installing a 60 space panel in a new house and it between the studs. How are you going to get 50 or so NM in their?

And if you can use a 18” nipple, why not a just MTA?


“ shoot low boys their riding shetland ponies”
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
You would have to come into the bottom of the panel as well with 50. There are ways to do it, just because its not convenient.......

I don't disagree with your comparison of 18" vs the TA. You still need to secure it. I personally don't like it because I think it looks elementary and its a violation , but I also don't see a big safety issue if you choose to violate the NEC.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Let’s just say you are installing a 60 space panel in a new house and it between the studs. How are you going to get 50 or so NM in their?

And if you can use a 18” nipple, why not a just MTA?
You said "between the studs" that would be prohibited using the 18" of raceway since the panel is not surface mounted.
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
So, why then do we do we not have to secure the NM to a plastic outlet box? What is the real difference between that and the NM going to a Mateo box( panel)? If it is true for one shouldn’t it be true for the other?


“ shoot low boys their riding shetland ponies”
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
So, why then do we do we not have to secure the NM to a plastic outlet box? What is the real difference between that and the NM going to a Mateo box( panel)? If it is true for one shouldn’t it be true for the other?
There is no real difference (other than the box is 8" max and the panel 12" max). IMO either one is safe but according to the NEC one is allowed and the other is not.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
For me if I'm inspecting a job and the photo in post #15 is what I see on the job-site the installer will be ripping it out and doing it correctly according to the NEC.

I agree because there is no reason to do this other than laziness. One can get into the top and bottom of the panel and you can use 2 nm cables per connector. No reason to not do it correctly
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
I agree because there is no reason to do this other than laziness. One can get into the top and bottom of the panel and you can use 2 nm cables per connector. No reason to not do it correctly

I wouldn’t call it laziness at all. For most guys it the way they always did it. And for me I just got into res. work a year ago from a commercial work before that so I, and others did what the company did. And as we learn more( as all of us do) we can implement the things we learn.

Laziness is not what it is at all, and for those who have done work like this, we all take offense to you calling our work lazy!


“ shoot low boys their riding shetland ponies”
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
I would say it not knowing any better.

If someone would say “the rule is in there because of this reason” that would help some of us learn how to do thing right and “to code”


“ shoot low boys their riding shetland ponies”
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I would say it not knowing any better.

If someone would say “the rule is in there because of this reason” that would help some of us learn how to do thing right and “to code”


“ shoot low boys their riding shetland ponies”


Whoever taught you this method was saving time and trying to avoid taking the right path. You yourself may not have known but surely your bosses knew.

Maybe laziness wasn't the best word but I can think of other words that aren't much better...LOL
 

McLintock

Senior Member
Location
USA
Occupation
Electrician
Whoever taught you this method was saving time and trying to avoid taking the right path. You yourself may not have known but surely your bosses knew.

Maybe laziness wasn't the best word but I can think of other words that aren't much better...LOL

This might be true, but when your boss is one who was “grandfathered” into the state licensing system and had never really picked up a code book and just went off what the inspector points out, you truly know no better.

I am trying to implement all the things I learn for the classes, code book, etc. into practice. It does not happen over night.

Can anyone tell me why it’s IN the code book?


“ shoot low boys their riding shetland ponies”
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
What specifically are you talking about? Do you mean the reason that cables should be connected to the box? That entire section is a bit strange and I am not sure many people understand the why's of allowing a conduit to sleeve a bunch of nm cables as long as it is 18" long etc, and why that is not allowed for a conduit going down.

I can guess the 18" is to protect arching inside the panel from escaping up thru the conduit but going down I am not sure why other than fire code.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I call it cutting corners to save time and money and increase profit. This has been in the NEC forever and that fact that someone was getting away with it doesn't make it right. I know it's a common practice in some places but unless there is a local amendment I blame the inspectors for not enforcing the code. There is another issue, in many places if there is a fire related to an installation like this then the contractor is liable not the inspector, just something else to chew on.
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Of course you all ultimately need to draw your own conclusions, were just on here to learn and share the code as we know it.
There is quite the historical background with this and CMP 9:
This small detail has been discussed allot by code experts for decades, so it stands out to me,
and the older wood frame type homes where this is commonly done tend to have old wiring and tons of dust and debris in the walls.

Its not just about over filling a switch box by one conductor or using a unlisted light fixture.


The proposal from the 1989 ROP:
1590203050694.png


In 2005 a proposal to delete “surface mounted” was investigated and rejected.

In 2008 this was rejected:
Submitter: Lanny G. McMahill, Phoenix, AZ
Recommendation: Add new Exception.

Exception: Cables with entirely nonmetallic sheaths shall be permitted to


enter the back of a surface-mounted enclosure through one or more nonflexible
raceways not more than 75 mm (3 in.) in diameter, and not less than 75 mm (3
in.) and not more than 600 mm (24 in.) in length, provided all of the following
conditions are met:

(a) Each cable is fastened within 200 mm (8 in.), measured along the sheath,
of the outer end of the raceway.

(b) The raceway extends directly into an enclosed wall space.
(c) A fitting is provided on each end of the raceway to protect the cable(s)
from abrasion.

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

(e) The cable sheath is continuous through the raceway and extends into the
enclosure beyond the fitting not less than 50 mm (2 in.).

(f) The raceway is fastened at its outer end in accordance with the applicable
article.
(g) The conductor size is maximum 10 AWG.

(h) The raceway shall be permitted to be filled to 60 percent of its total crosssectional area, and 310.15(B)(2)(a) adjustment factors need not apply to this
condition.
Substantiation: This is a standard wiring practice allowed in many
jurisdictions for the past 30 years. This is a safe and reasonable wiring practice
for surface mounted enclosures. This proposal is intended to modify the
practice. The proposed language is intended to mirror the current exception;
yet, it incorporates more restrictions and clarification. The current exception
allows Type NM cables to enter a raceway in the top of a surface mounted
enclosure. This exception allows Type NM cables to enter a raceway in the
back of a surface mounted enclosure. Additional restrictions include:

1) The raceway is limited to a maximum 3 inches in diameter, and restricted
to between 3 inches and 24 inches in length. The 3 inches in diameter is to
restrict the size of the opening in the back of the enclosure. The minimum
length is to ensure that the raceway extends into the wall space. The maximum
length is to allow for greater depth of wall and additional flexibility in
installation.

2) The cable must be fastened within 8 inches of the raceway end. This
mirrors the requirement noted in 314.17(C)1 Exception. It also allows for better
securing of the cables.

3) The raceway must extend into an enclosed wall space. This is intended to
prevent access to the cables and provide a degree of protction from access to
the enclosure.

4) The raceway must be sealed or pluged at the inner end to prevent access.
5) The cable sheath must extend at least 2 inches into the enclosure. The
current exception only requires 1/4 inch.

6) The conductor size is restricted to 10 AWG. This is to prevent larger
cables from entering the opening.

7) The raceway is restricted to 60 percent fill and adjustment factors need not
apply.

Panel Meeting Action: Reject
Panel Statement: The use of short fittings as described is a potential hazard,
because an arc in the panel may no longer be contained by the enclosure.
CMP-9 has discussed this approach repeatedly over many cycles, and does not
agree that it should be allowed. The literal text of this proposal would allow a 3
rade size connector anywhere in the back of a panel, even close to the busbars
and even if only a handful of small cables pass through it.
Number Eligible to Vote: 11
Ballot Results: Affirmative: 10
Ballot Not Returned: 1 de Vega, H.
 

Another C10

Electrical Contractor 1987 - present
Location
Southern Cal
Occupation
Electrician NEC 2020
Ok, I was up for this challenge of, is it legal to run one mombo Pvc connector to run a whole panels branch circuit system through, which I've seen and to me is lazy as , well you know ...

If I was an Inspector I'd say .. check 334.30 ... right were is says within every support within 12" of enclosure such as outlet boxes cabinet or ( fittings ) the key word is then fittings or should I say approved fittings, a pvc fitting does not maintain the clamp or crimp that a NMB connector possesses, So the argument would then be, what is an approved soft sheathed connector, does it need to be lightly compressed to prevent slippage. Anyone care to contribute to the question of using a pvc fitting or even just a large chase nipple. Besides I'm sure there's a violation just by having 3" of cables crammed together like that.

check 334.30 (A) other than they refer to horizontal I'm sure the NEC board would consider this as an applicable situation, as noted : and the non metallic sheathed cable is securely fastened in place by an approved means of each .. .. cabinet .. ( or other non metallic cable termination )

PVC connectors are not non metallic cable termination fittings.
 
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