NM cables in panel opening

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satox

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I ran into an panel install that had one 1 inch hole in back of the panel jammed tight with 5 cables 1 14/2, 3 6/3 and 1 10/3. The cables go right out the back of the panel through the wall of the house .

This looks really wrong (especially no strain relief or cable protection) , what are the limitations on running cables through holes in (the back) main panels? There is a 2 inch knockout that I'm thinking about using . How many 12/2 nmc can I put in this knockout ?
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
satox said:
I ran into an panel install that had one 1 inch hole in back of the panel jammed tight with 5 cables 1 14/2, 3 6/3 and 1 10/3. The cables go right out the back of the panel through the wall of the house .

This looks really wrong (especially no strain relief or cable protection) , what are the limitations on running cables through holes in (the back) main panels? There is a 2 inch knockout that I'm thinking about using . How many 12/2 nmc can I put in this knockout ?
Click to expand...

Zero. In this installation each cable needs to be secured to the panel enclosure.
 
jumper

jumper

Senior Member
Location
3 Hr 2 Min from Winged Horses
If you are thinking of using something like this:

20477-a_2.jpg


I do not think it will fly.
 
Steviechia2

Steviechia2

Senior Member
Location
Massachusetts
raider1 said:
Agreed, 312.5(C) is the code section.

Chris
Click to expand...

If you use a large enough romex or SEU connector I would say each cable would be secure. As far as what the manufactures rating of the connector goes I don't know? To me this is not really a safety issue as long as it's secured.
 
raider1

raider1

Senior Member
Staff member
Location
Logan, Utah
Steviechia2 said:
If you use a large enough romex or SEU connector I would say each cable would be secure. As far as what the manufactures rating of the connector goes I don't know? To me this is not really a safety issue as long as it's secured.
Click to expand...

Most NM connectors are designed for connecting no more than 2 cables, so if you put 5 cables in a 2" connector you will violate the connectors listing.

With large NM/SE connectors if you put in 4 or 5 cables the cables in the center of the bundle really aren't support except by pressure from other cables.

Chris
 
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satox

Member
I apologize if I'm missing the point or over complicating things but 312.5(C) lists an exemption for surface mounted boxes... this box I'm dealing with is recessed.
, so I think I'm screwed.

The question is if cables enter from the back of the enclosure and there are not enough knockouts for even 2 cables per hole, there is one 3/4" KO and one 2" ... the other 2" is packed with 5 cables. What does the seasoned electrician need to do (who wants to pass inspection)?
.
A. Account for Chapter 9 table 4 limitations and fill 2 inch KO with 6 12/2 nm.
B. Run cables through holes and secure 12" from opening.
C. Drill required number of holes and strain relief each cable.
D. Replace the enclosure
E. None of the above
 
raider1

raider1

Senior Member
Staff member
Location
Logan, Utah
satox said:
I apologize if I'm missing the point or over complicating things but 312.5(C) lists an exemption for surface mounted boxes... this box I'm dealing with is recessed.
, so I think I'm screwed.

The question is if cables enter from the back of the enclosure and there are not enough knockouts for even 2 cables per hole, there is one 3/4" KO and one 2" ... the other 2" is packed with 5 cables. What does the seasoned electrician need to do (who wants to pass inspection)?
.
A. Account for Chapter 9 table 4 limitations and fill 2 inch KO with 6 12/2 nm.
B. Run cables through holes and secure 12" from opening.
C. Drill required number of holes and strain relief each cable.
D. Replace the enclosure
E. None of the above
Click to expand...

I say C, drill holes and use proper NM cable connectors.

Chris
 
S

satox

Member
Thanks raider.. I've combed the forum archive and Internet and this question has been asked here before. Seems like inspectors choice.

It seems like there are many more stuffed holes out there than one would realize. I see this all the time.

NEMA, Cutler or who ever spec/makes rear entry enclosures should account for the +10 3/4" knockouts that need to be in residential recessed boxes.

It seems like the NEC requires a method that isnt used or enforced very often.

Pictures are worth 1000 words in this case.
 
raider1

raider1

Senior Member
Staff member
Location
Logan, Utah
Your welcome.:)

You are correct, there are many places that permit the use of a single 2" bushing or connector to connect multiple cables. This practice is a violation of 312.5(C) but many places either ignore it or are unaware of it.

Chris
 
2

220/221

Senior Member
Location
AZ
raider1 said:
Your welcome.:)

You are correct, there are many places that permit the use of a single 2" bushing or connector to connect multiple cables. This practice is a violation of 312.5(C) but many places either ignore it or are unaware of it.

Chris
Click to expand...

Or have local codes that supercede the NEC.
 
acrwc10

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
There are some Plastic NM connectors ( made by Arlington ) that are listed for 3 NMs in a 3/4" fitting. Other then that you have just run across one of the most common violations I see. "too many NM's in a fitting, violates the listing of the fitting."
I have in the past brought multiple NM into a box :4sq, or 4-11/16" through multiple KOs then used a nipple to bring the conductors into the panel. Some times you have the space, sometimes you don't. Good Luck. Just remember if all the NM's are jambed into a single 2'' connector, if one burns up, more then likely they will all burn. (seen it happen, not pretty.)
 
glene77is

glene77is

Senior Member
Location
Memphis, TN
jumper said:
And if he can not.......?:-?
Click to expand...

Jumper,

Maybe visit the code enforcement office
and ask for a variance to run all the NM into a single 2" Nipple.

Mount a JB outside,
patch new NM
and run these back through the wall
and swing them under to the proposed new holes.

I don't see any options that I like.
 
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