Panel as junction box versus doubletap on circuit breaker

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I know a double tap on a lug that is not rated or listed for connection of more than one conductor is not allowed. I am of understanding that a panel is not to be used as a junction box. It a case where RGS conduits entering the panel are not accessible (stub up into bottom of panel located in a poured block wall). Is it permissible to wire nut the double tap to one conductor and land one conductor on breaker...or is the fix to be cutting open wall to access the conduits to cut in junction box below. Any suggestions with code references allowing the joints within panel OR is channeling block to expose conduit and setting junction box only allowed solution?

Your wisdom and insights greatly appreciated!

Steve
 

user 100

Senior Member
Location
texas
I know a double tap on a lug that is not rated or listed for connection of more than one conductor is not allowed. I am of understanding that a panel is not to be used as a junction box. It a case where RGS conduits entering the panel are not accessible (stub up into bottom of panel located in a poured block wall). Is it permissible to wire nut the double tap to one conductor and land one conductor on breaker...or is the fix to be cutting open wall to access the conduits to cut in junction box below.

Your wisdom and insights greatly appreciated!

Steve

Joints ​are allowed in panels- who told you you can't?

In fact the wire nutted double tap "fix" is done quite often.:)
 

Dennis Alwon

Moderator
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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Hope this helps. As stated above the nec allows splices in the panel

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 complying with 110.21(B) is applied
to the enclosure that identifies the closest disconnecting
means for any feed-through conductors.
 

kenman215

Senior Member
Location
albany, ny
I know a double tap on a lug that is not rated or listed for connection of more than one conductor is not allowed. I am of understanding that a panel is not to be used as a junction box. It a case where RGS conduits entering the panel are not accessible (stub up into bottom of panel located in a poured block wall). Is it permissible to wire nut the double tap to one conductor and land one conductor on breaker...or is the fix to be cutting open wall to access the conduits to cut in junction box below. Any suggestions with code references allowing the joints within panel OR is channeling block to expose conduit and setting junction box only allowed solution?

Your wisdom and insights greatly appreciated!

Steve

Ever installed an eight circuit manual transfer switch before? 1 1/2" greenfield carry a breaker feed in and out. Your couple of splices is bound to look better than that my friend.
 
NEC Article 373-8 compared to 312-8

NEC Article 373-8 compared to 312-8

I don't know when 373-8 evolved to 312-8. I believe the incorrect interpretation of portion of 373-8 contained the phrase "taps, splices, etc. SHALL NOT be allowed in enclosures, auxiliary gutters," Etc. & so on, - followed by a coma and the word unless and then listing items 1 & 2 listed in 312-8...perhaps lazy reading or urban electrical legend as my interpretation of both has/had been splices on double tapped branch circuit are allowed. I submitted both articles to my superior and am waiting for his response. He is a knowledgeable, reasonable and logic man who is big enough to admit when he is wrong.


Once again, thank you gentlemen for your knowledge and acumen.

Steve
 

kwired

Electron manager
Location
NE Nebraska
I don't know when 373-8 evolved to 312-8. I believe the incorrect interpretation of portion of 373-8 contained the phrase "taps, splices, etc. SHALL NOT be allowed in enclosures, auxiliary gutters," Etc. & so on, - followed by a coma and the word unless and then listing items 1 & 2 listed in 312-8...perhaps lazy reading or urban electrical legend as my interpretation of both has/had been splices on double tapped branch circuit are allowed. I submitted both articles to my superior and am waiting for his response. He is a knowledgeable, reasonable and logic man who is big enough to admit when he is wrong.


Once again, thank you gentlemen for your knowledge and acumen.

Steve

373 evolved to 312 probably around 1999 or 2002. That is about the time they moved several articles to new locations or merged some into others as an effort to make the code easier to use and follow. Most content never really had much change just things got moved around.

I do believe you must have had some incorrect interpretation at some point as even before the moving around it there was still the 40 and 75 percent rules relating to splices and taps in this area.

Also make note you don't splice in the "panel", Art 373 - now 312 is for "cabinets, cutout boxes, and meter enclosures" which is what you are making the splice/tap in, the panelboard is the assembly inside the cabinet that contains overcurrent devices, bus bars, etc.
 

user 100

Senior Member
Location
texas
.....must have had some incorrect interpretation at some point......


Oh with some guys ( this is not directed at the op) this goes beyond misinterpretation- they simply don't like wirenut splices in panels.

They consider them representative of unprofessional work or some other goofy reason/obsession with aesthetics (it's always ground down, ground DOWN, I tells you!!:lol:).

Yet their usual alternative solutions are nothing more than a pointless waste of time and material ($$$)- which is completely unacceptable.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
I am of understanding that a panel is not to be used as a junction box.
It amazes me how persistent this mis-interpretation of the Code has been.

I was gigged by a State electrical inspector back in 1983 for this. The requirement, back then, was in 373-8 of the 1981 NEC, and, in the soft bound book, was at the bottom of the page. It was a nice, neat little passage that said, point blank, "Enclosures for switches or overcurrent devices shall not be used as junction boxes. . . " and this is also the passage that says you can't run a wire through an enclosure on its way to somewhere else.

Right there at the bottom of the page. Ends in a period. A single sentence.

Of course, if one lifts their eyes to the top of the NEXT page, there is an Exception. The Exception plainly lays out the 40% fill requirement, i.e., splices and feed-throughs are allowed if there is enough space (40% fill).

Quote the inspector, "Oh, I didn't see that."
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
Oh with some guys ( this is not directed at the op) this goes beyond misinterpretation- they simply don't like wirenut splices in panels.

They consider them representative of unprofessional work or some other goofy reason/obsession with aesthetics (it's always ground down, ground DOWN, I tells you!!:lol:).

Yet their usual alternative solutions are nothing more than a pointless waste of time and material ($$$)- which is completely unacceptable.
So true.
 
I will preface the following by emphatically stating I am neither pro or con union and please don't turn this into a union/non-union debate.

I sometimes read through the pages of electricians groups on Facebook.

A lot of the union guys seem to think that splices in panels are "unprofessional" and "ugly"......it's as if they have never worked in the real world, but I guess that if one has only ever worked on new construction, a splice in a panel constitutes a miscalculation of conductor length.
 
AHJ - 373-8 312-8 & other "Really?" Moments

AHJ - 373-8 312-8 & other "Really?" Moments

I have "discussed" at length these sections of code. I thank all you gentlemen for you comments and input.

I have had inspectors who (not relating to this issue) Fail service inspection, because they could not "see" the connection to the ground rod even though a pole mounted service with grounding conductor nailed to pole leading to rod six inches from base installed below grade per code. Demand a back-fed 30/2 main for a 120/240 code minimum pole service installed with six circuit 3R panel with 1 20/1 feeding into 3R j-box below with single 20A receptacle in handy box to provide power to an irrigation timer, because inspector "felt" additional load might be added. We are talking in the boondocks locations with obviously no other loads to be connected in future...I disagreed, pointed out the exact code references allowing installations and LOST to NEC AHJ has final authority. I did win one using illustrated NEC Handbook, when the inspector failed service replacement stating the "meter & panel" too close to the window. I pointed out my NEC reference and my understanding (with the lovely picture diagram) that service entrance "CONDUCTORS" could not be within 3' of a door or window to prevent people accidental contact...

Greatest amount of egg on my face early in my career (Oh my gosh, 38 years where did they go) - : Building a residential 400A single phase 120/240 service for one of our commercial customer presidents who adding a covered pool with motorized dampers...I ordered long barrel compression lugs for the 500KCMIL cu service entrance conductors...electrician called me to say local utility would not tap meter because of lugs, we were to cut and use short barrel mechanical lugs provided with the meter...I LEFT FOR JOB AND went off on the utility foreman with "Are you trying to tell me these short mechanical lugs, (waving one in his face) are better wiring connections than these long barrel crimp connections in the meter can?" He smiled appreciating my young animation and said, "No sir, I'm not telling you that the lug in your hand is an "APPROVED" connection"...they weren't Burndy, Blackwell or other approved they were SQD...exit left with apology...

Have a great new year everyone...Here's a toast for profitable projects, installed with pride in a neat and workmanlike manner!!!

Last but not least:
Sad statistic from trade magazine EC or ECM 4 years ago...Average age journeyman electrician (at that time) was 56 years old...

Steve
 
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