Can an electric panel be used a junction box?

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davedan

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Dear friends

I heard some people including an inspector saying that it is incorrect, but others including another inspector saying it is acceptable based on the fact that NEC 312.8 includes a conditional sentence starting with "..UNLESS adequate space for this purpose is provided". Next sentences provide more details about that exception.
I would appreciate your comments and experiences about it.
 
312.8 is the only limiting factor and in most cases the or splices can be installed without violation especially if we are talking about smaller branch circuits.
 
You're allowed up to 75% fill for the splices. For all practical purposes you cannot exceed that number even if you tried. :roll:
 
I have allowed electricians to use existing panels as junction boxes; as long as the hinged door is screwed shut. This way the existing panel cover acts as your cover plate. It should also be marked accordingly. :thumbsup:
 
ngd4130 said:
I have allowed electricians to use existing panels as junction boxes; as long as the hinged door is screwed shut. This way the existing panel cover acts as your cover plate. It should also be marked accordingly. :thumbsup:
Click to expand...

What code section requires the door to a cabinet be screwed closed?

What code section requires it be marked?

I posted the following on another forum recently and will recycle it here .....


Can I gut an exsisting sub panel and use it to make junctions to send wires to new sub panel? I need a code reference for this one. I discussed with AHJ and they weren't sure either... Lol!
Click to expand...


To the NEC a panelboard is the bus bars and such.

From Article 100
Panelboard. A single panel or group of panel units designed
for assembly in the form of a single panel, including
buses and automatic overcurrent devices, and equipped
with or without switches for the control of light, heat, or
power circuits; designed to be placed in a cabinet or cutout
box placed in or against a wall, partition, or other support;
and accessible only from the front.
Click to expand...

So as you can see a panelboard is installed in a cabinet.


From Article 100
Cabinet. An enclosure that is designed for either surface
mounting or flush mounting and is provided with a frame,
mat, or trim in which a swinging door or doors are or can
be hung.
Click to expand...


So your question is really 'Can you splice in a cabinet?'

Lets look at Article 312.




ARTICLE 312
Cabinets, Cutout Boxes, and Meter
Socket Enclosures

312.1 Scope. This article covers the installation and construction
specifications of cabinets, cutout boxes, and meter
socket enclosures.
Click to expand...

So we are in the right place, and assuming you remove the overcurrent devices this is about the only section you need to worry about.


312.7 Space in Enclosures. Cabinets and cutout boxes
shall have sufficient space to accommodate all conductors
installed in them without crowding.
Click to expand...

So don't crowd it .... whatever that means.

If for whatever reason you leave the overcurrent devices in the cabinet you would have to worry about this section.


312.8 Enclosures for Switches or Overcurrent Devices.
Enclosures for switches or overcurrent devices shall not be
used as junction boxes, auxiliary gutters, or raceways for conductors
feeding through or tapping off to other switches or
overcurrent devices, unless adequate space for this purpose is
provided. The conductors shall not fill the wiring space at any
cross section to more than 40 percent of the cross-sectional
area of the space, and the conductors, splices, and taps shall
not fill the wiring space at any cross section to more than
75 percent of the cross-sectional area of that space.
Click to expand...
 
The text highlighted in red in the above post has been a sticking point on other forums. The are emphasizing the "space for this purpose" and changing the intent of that section. Some believe that the space must somehow be identified as available for the splices. Until is is identified it is not for this purpose.
 
jimport said:
The text highlighted in red in the above post has been a sticking point on other forums. The are emphasizing the "space for this purpose" and changing the intent of that section. Some believe that the space must somehow be identified as available for the splices. Until is is identified it is not for this purpose.
Click to expand...

Above I posted the 2008, here is the 2011 any questions have been removed.

312.8 Switch and Overcurrent Device Enclosures with
Splices, Taps, and Feed-Through Conductors. The wiring
space of enclosures for switches or overcurrent devices
shall be permitted for conductors feeding through, spliced,
or tapping off to other enclosures, switches, or overcurrent
devices where all of the following conditions are met:

(1) The total of all conductors installed at any cross section
of the wiring space does not exceed 40 percent of the
cross-sectional area of that space.

(2) The total area of all conductors, splices, and taps installed
at any cross section of the wiring space does not
exceed 75 percent of the cross-sectional area of that
space.

(3) A warning label is applied to the enclosure that identifies
the closest disconnecting means for any feedthrough
conductors.
Click to expand...
 
iwire said:
What code section requires the door to a cabinet be screwed closed?

What code section requires it be marked?

I posted the following on another forum recently and will recycle it here .....





To the NEC a panelboard is the bus bars and such.

From Article 100


So as you can see a panelboard is installed in a cabinet.


From Article 100



So your question is really 'Can you splice in a cabinet?'

Lets look at Article 312.




So we are in the right place, and assuming you remove the overcurrent devices this is about the only section you need to worry about.




So don't crowd it .... whatever that means.

If for whatever reason you leave the overcurrent devices in the cabinet you would have to worry about this section.
Click to expand...

Well thought out and correct response, thanks for posting it
 
Gotta love this forum

Gotta love this forum

Thanks Iwire and all.

Looked at a job today and planned to gut existing bussbars, etc. from cabinet and use as big splicebox, but was concerned as to if it would be code compliant or not. what happens? I come home and do my nightly reading on the forum and wouldn't you know it... Once again Iwire has provided the complete, clear, succinct and to the point information before I even had to ask it.

I'm often amazed at how proficient some of you are with your code books and how much diversified code some of you just have stored in the old noggins. I'm lucky I can remember which dresser drawer my socks are in. As always, thank all of you for sharing your time and knowledge, as it makes this simpletons ability to earn a living, provide for his family and help out in his community alittle easier.
 
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