Failed inspection for two cables in one plastic K/O

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rt66electric

Senior Member
Location
Oklahoma
different insp, different song

different insp, different song

I have had a inspector "request" the opposite If you had two cables the he/and/fire marshall "preferred" that the two cables should enter the same hole instead of two holes. His reasoning was less air-gap for combustion air....... I agreed to do it thusly in the future..... and he gave me a green sticker.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
I agree that two cables in a KO is OK for 1-gangs, and that screw heads inside the box are not.

I don't like the One Box for old work, because I don't want to always have to mount it to a stud.

Inspector says no more then one wire per hole and cited a local supplementary code in Sacramento county. However I can't find any information in their supplementary code or find a UL listing issue to verify.
I would have insisted on the code section immediately, but tactfully. Something like:

"Oh, thanks! I hadn't read that one. Can you show me that section so I get it right?"
 

JohnE

Senior Member
Location
Milford, MA
Just got some further clarification on multiple entries per knock out

Single gang boxes = ok
Multiple gang boxes = not ok

Unless something's changed, thats not local ordinance it is new. (I know, I'm too lazy to go look it up)

Everyone does that around here and it I've never seen it failed. As far as "well it is a violation", I've never passed a job that doesn't have some sort of inconsequential violation. Like the 13" staple job previously mentioned.
 

kwired

Electron manager
Location
NE Nebraska
Unless something's changed, thats not local ordinance it is new. (I know, I'm too lazy to go look it up)

Everyone does that around here and it I've never seen it failed. As far as "well it is a violation", I've never passed a job that doesn't have some sort of inconsequential violation. Like the 13" staple job previously mentioned.

I have had to correct this problem 15 or so years ago - it has been a requirement at least since the 93 code.
 

stevenje

Senior Member
Location
Yachats Oregon
I got nailed on a piece of nm cable in the middle of a 3' high crawl space because I dropped down to the furnace box and I was 13" from the box with a staple. I had to drive 10 miles one way to put a dang board down and staple it within 12 inches. That was the only thing he got me on.

New math:
20 miles + 1 "dang board" = 1 inch ;)

Have a safe and happy 4th everyone.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
He could be a very knowledgeable guy but goes by the book. Some inspector can get a little nuts with it but that's what they get paid for.

I got nailed on a piece of nm cable in the middle of a 3' high crawl space because I dropped down to the furnace box and I was 13" from the box with a staple. I had to drive 10 miles one way to put a dang board down and staple it within 12 inches. That was the only thing he got me on.

I know an old inspector who would have said, "you didn't miss it by an inch, you missed it by twelve inches.":grin:

Personally I'll take something over nothing. "oh, you want a staple there?":roll:
 

jmellc

Senior Member
Location
Durham, NC
Occupation
Facility Maintenance Tech. Licensed Electrician
Everytime I see one of those boxes I have to kick myself and scream why didn't I market the old screw thru the side of the box thing I did for all those years :mad::D.
Tell me about it. I'm still kicking myself that I didn't invent stackers. I had the idea back in the 70's. Thought how great such a thing would be. I don't know just when they came out. I was out of the trade for several years and did all commercial when I started back. Then worked with a friend of mine who pulled out a bag of stackers. That was in 2004. I've been kicking myself ever since. If only I'd used my head and worked on the idea back then.
 

kwired

Electron manager
Location
NE Nebraska
314.17(C) and exception


(C) Nonmetallic Boxes and Conduit Bodies. Nonmetallic boxes and conduit bodies shall be suitable for the lowest temperature-rated conductor entering the box. Where nonmetallic boxes and conduit bodies are used with messenger-supported wiring, open wiring on insulators, or concealed knob-and-tube wiring, the conductors shall enter the box through individual holes. Where flexible tubing is used to enclose the conductors, the tubing shall extend from the last insulating support to not less than 6 mm (? in.) inside the box and beyond any cable clamp. Where nonmetallic-sheathed cable or multiconductor Type UF cable is used, the sheath shall extend not less than 6 mm (? in.) inside the box and beyond any cable clamp. In all instances, all permitted wiring methods shall be secured to the boxes.

Exception: Where nonmetallic-sheathed cable or multiconductor Type UF cable is used with single gang boxes not larger than a nominal size 57 mm ? 100 mm (2? in. ? 4 in.) mounted in walls or ceilings, and where the cable is fastened within 200 mm (8 in.) of the box measured along the sheath and where the sheath extends through a cable knockout not less than 6 mm (? in.), securing the cable to the box shall not be required. Multiple cable entries shall be permitted in a single cable knockout opening.

Cables are required to be secured to all non metallic boxes - I have not seen a box with integral clamps that are rated for more than one cable per entry, if there is one available then you can have multiple entries per mfg instructions. The exception to 314.17(C) allows cables to not be secured to the box if the cable is fastened within 8 inches, as well as multiple cable entries all this exception is for single gang boxes only.

There is no new requirements here, I have had to correct violations to this section at least 17 -18 years ago, not sure how long these requirements have been there though, probably longer than 17 - 18 years, that is just when it was first brought to my attention that what I was doing was wrong.
 

kwired

Electron manager
Location
NE Nebraska
Blue plastic carlon boxes using 14-2 NM. Currently have two wires going into each entry on the side closest to the stud.

Inspector says no more then one wire per hole and cited a local supplementary code in Sacramento county. However I can't find any information in their supplementary code or find a UL listing issue to verify.

http://qcode.us/codes/sacramentocounty/view.php?topic=16-16_28-16_28_100&frames=on

Any help on the subject would be great. :)

Dos NEC 314.17(c) apply in this case?

314.17(C) exception does apply - if a single gang box, what did you have?
 

hardworkingstiff

Senior Member
Location
Wilmington, NC
I got nailed on a piece of nm cable in the middle of a 3' high crawl space because I dropped down to the furnace box and I was 13" from the box with a staple. I had to drive 10 miles one way to put a dang board down and staple it within 12 inches. That was the only thing he got me on.

That's like getting a speeding ticket for doing 56 in a 55.
 

oldchap

Member
Two cables through one plastic box knockout

Two cables through one plastic box knockout

Would the exception for 314.17(c) fit your situation? After listing certain stipulations the exception concludes with "Multiple cable entries shall be permitted in a single cable knockout opening."
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Would the exception for 314.17(c) fit your situation? After listing certain stipulations the exception concludes with "Multiple cable entries shall be permitted in a single cable knockout opening."
It would if there's no overriding local law.
 

jmellc

Senior Member
Location
Durham, NC
Occupation
Facility Maintenance Tech. Licensed Electrician
That's what face-nailers are for.

B118B-UPC.jpg

This type of KO looks designed for 2 cables to me. If you remove the entire tab, 1 cable is too loose. Pop it and turn it, 2 cables fit nicely, 1 each side of tab. 1 only & have a blank space other side of tab.

The gray boxes most supply houses carry have the slit type KO, it gives against wire pressure, or may need a screwdriver popped in the center. Those type are much better with only 1 cable per KO.

I like the nailing bracket. Some places carry a cut in box with interior screw shields, allowing cutting in next to a stud and using screws, with screws entirely isolated from wiring.

Don't have my book handy, but I think screws in the back of the box are legal, if smooth headed & no thread showing. Wafer head screws are a good example. I may be wrong on that, will check when I have a chance.
 

rt66electric

Senior Member
Location
Oklahoma
72 hr rule

72 hr rule

Except now the entire project is being held up because I can't get a re inspection until Tuesday because of furlough Friday and a Monday holiday :confused:

There is a little know rule/law " If a inspector cannot get to a job in 72 hrs, then it is considered "good" " OK to cover up.

check your local state rules

my local inspector is aware of this rule, most electricians are not,

I have used this rule once to keeep the job going.

I was out of town and not coming back>
 
There is a little know rule/law " If a inspector cannot get to a job in 72 hrs, then it is considered "good" " OK to cover up.

check your local state rules

my local inspector is aware of this rule, most electricians are not,

I have used this rule once to keeep the job going.

I was out of town and not coming back>


That is not so in NYS. There are some local laws regarding this, but never permittng a job without inspection.




In regards to the plastic boxes and number of cable entries.

The information can be found in:

314.17(C) Exception - (last sentence)
"Multiple cable entries shall be permitted in a single cable knockout opening"

This is in regards to an earlier portion of the same paragraph referencing 2-1/4 in. X 4 in. plastic boxes.


**Also look under (QCMZ) in the UL White Book - see the bold portion labeled - SINGLE-GANG BOX
 
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LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
There is a little know rule/law " If a inspector cannot get to a job in 72 hrs, then it is considered "good" " OK to cover up.
That is not so in NYS. There are some local laws regarding this, but never permittng a job without inspection.
Same here. If we don't want to wait for the inspection the permit fee covers, we're free to hire our own private inspector, at our cost.
 

wireguy8169

Senior Member
Location
Southern Maine
He's being very picky he also called using screws inside the box instead of the exterior nails. Couldn't get the hammer in a couple tight spots.

This is not an answer to your post but, when I have a spot that I can not get a hammer in I have an old set of linemans pliers if you put the flat side on the nail head and hit the other side of the pliers with the hammer it will drive the nail typically: you could use a flat bar too just hit what ever you do as close to the outside of the stud as you can. Maybe you know this but thought I would share it. :grin:
 

kwired

Electron manager
Location
NE Nebraska
There is a little know rule/law " If a inspector cannot get to a job in 72 hrs, then it is considered "good" " OK to cover up.

check your local state rules

my local inspector is aware of this rule, most electricians are not,

I have used this rule once to keeep the job going.

I was out of town and not coming back>


That rule where it exists is to keep inspections (or lack of them because the inspector doesn't show up within reasonable time) from holding up the project.

It does not mean that if the inspector shows up in 84 hours instead of 72 that he still can't fail anything that he can see, he just can't require uncovering anything solely for the purpose of inspecting it, without reasonable cause to think something is wrong.

As far as the original topic - if two cables are not allowed in a KO you cannot use the "72 hour" rule to cover up. The two cables would still be visible inside the box and are still subject to being inspected. Inspector would not be able to make you remove drywall to see how they were supported within the wall, but he could clearly see that you have two cables in an opening that only allows one.
 
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