Running EMT out of an Extension box

[scottam99]

I'm in Orlando Florida, I was told by one of my fellow employees that the electrical inspector will not allow us to pipe out of an extension box which is attached to a 4 square box. I consider myself to be very code literate and I have never heard of this before.
My colleague said the box has to be removable therefore no conduit can be installed in it.
Any thoughts??

 

[masterinbama]

Extension ring yes, cover no.

 

[infinity]

Extension ring yes, cover no.

I agree, extension collar boxes have KO's for a reason.

 

[Smart $]

...
My colleague said the box has to be removable therefore no conduit can be installed in it.
Any thoughts??

I agree with other replies...

That said, one scenario where your colleague may be correct is when you add the extension to an existing installation with wires already in the box and spliced. The wires may have been long enough to meet the minimum required length in the box before putting on the extension... but afterwards are too short to consider the extension as part of the box. Unless you can per se "stretch the wire" (read get some slack from other end or re-pull), the only alternative is to consider the extension as part of the cover and must remain removable (not a strict interpretation of Code and listing, but someone might buy it :slaphead.

 

[scottam99]

The installation I am speaking of is this; The extension was placed on a 4 square box no wire was pulled yet. reason for the extension box was to pass by a conduit that was close to the 4 square box. I see no reason the inspector would say this isn't acceptable.

 

[jumper]

Perfectly legal.

 

[jumper]

I agree with other replies...

That said, one scenario where your colleague may be correct is when you add the extension to an existing installation with wires already in the box and spliced. The wires may have been long enough to meet the minimum required length in the box before putting on the extension... but afterwards are too short to consider the extension as part of the box. Unless you can per se "stretch the wire" (read get some slack from other end or re-pull), the only alternative is to consider the extension as part of the cover and must remain removable (not a strict interpretation of Code and listing, but someone might buy it :slaphead.

One would only need to splice the conductors to extend them to the necessary length if needed.

 

[Smart $]

One would only need to splice the conductors to extend them to the necessary length if needed.

With a "loose" interpretation of the requirement, yes. Under a "strict" interpretation, that would be non-compliant, especially if using an easily undone splicing means such as wire nutting. I think the intent of the requirement is so one can make or break all splices outside the opening when the box is small.

 

[jumper]

With a "loose" interpretation of the requirement, yes. Under a "strict" interpretation, that would be non-compliant, especially if using an easily undone splicing means such as wire nutting. I think the intent of the requirement is so one can make or break all splices outside the opening when the box is small.

2008 ROP:

3-76 Log #1340 NEC-P03
Final Action: Reject
(300.14)
____________________________________________________________
Submitter:
Mike Holt, Mike Holt Enterprises
Recommendation:
Add the word ?unspliced?
300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points.
At least 150 mm (6 in.) of free
, unspliced,
conductor, measured from the
point in the box where it emerges from its raceway or cable sheath, shall be
left at each outlet, junction, and switch point for splices or the connection of
luminaires (fixtures) or devices. Where the opening to an outlet, junction, or
switch point is less than 200 mm (8 in.) in any dimension, each conductor shall
be long enough to extend at least 75 mm (3 in.) outside the opening.
Substantiation:
This change is to clarify that the free length of conductor is
required to be unspliced. As written, the code is vague as to whether or not the
conductor is permitted to contain a splice in the free length aforementioned.
Panel Meeting Action: Reject
Panel Statement:
The purpose of Section 300.14 is to permit access to the
end of the conductor. Whether this conductor is spliced or un-spliced does not
affect the length of this free end of the conductor. Many conductors originate
inside the box and are spliced to other conductors within the box but extend out
of the box for connection to a device of some kind. Making this change would
not permit this very common application. Even the exception to this section
states that unspliced or unterminated conductors do not have to comply with
300.14.
Number Eligible to Vote: 13
Ballot Results:
Affirmative: 13

 

[Smart $]

2008 ROP:

3-76 Log #1340 NEC-P03
Final Action: Reject
(300.14)
...

Thanks for the ROP... but you'll note I didn't say it was without a doubt non-compliant. Not all AHJ's refer to ROP's to make interpretations. Additionally, my original comment said if the conductor was too short. I just didn't mention anything about extension by splice to make it compliant. IMO, more often than not, when adding an extension ring to a box with existing spliced conductors, the electrician at most only extends the conductors that are modified to enter or exit via the extension ring, leaving the rest intact as is, without any consideration for being too short to be compliant.