Wire splices in service equipment panel

[Jeff Eastman]

.......

[Jerry Peck]

Is there not a code that states that pass through wiring (using the service equipment panel as a junction box) is a forbidden?

Yes. :D

[Jerry Peck]

Describe what you have better, if you would. :)

A photo would help address the right code wording.

[neal lewis]

Isn't there a qualification that says the pass through wiring is not allowed "only if there is insufficient space for the wiring" ?

[Jerry Peck]

Isn't there a qualification that says the pass through wiring is not allowed "only if there is insufficient space for the wiring" ?

Actually, it says "if space is provided for that purpose", and NO manufacturer "provides space for that purpose". There is no listing for it, no test for it, nothing.

Now, *IF* "space were provided for that purpose", THEN (and only then) would the percentage of fill come into play.

[James Duffin]

Where is it in the code where you can't leave the panel with a circuit and then come back in to the breaker...like to add a switch to a circuit?

I know it's there but I can not find it...

[Jerry Peck]

Where is it in the code where you can't leave the panel with a circuit and then come back in to the breaker...like to add a switch to a circuit?

Not following you on that.

You start out at the breaker, you then leave the panel to go to a switch and light, receptacle outlet, etc.

But where does the 'come back in' part fit in there?

The panel is not rated as a junction box or as a raceway, however, if you are just "splicing on" to make a conductor longer, you are still "just terminating that conductor in the panel" so it is not prohibited.

You are not allowed to run other conductors with service entrance conductors, you may run other conductors with feeder conductors, so it depends on what goes where.

[Richard Rushing]

Reference:

NEC 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 throuch 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 corss-sectional area of that space.

Richard

[Jerry Peck]

Richard,

Here is that reference with bold and underlining

NEC 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.

Being as there is no listing or labeling standard which provides space "for that purpose", no panel have been tested, listed, or labeled "for that purpose".

[Thom Walker]

Richard,

Here is that reference with bold and underlining

NEC 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.

Being as there is no listing or labeling standard which provides space "for that purpose", no panel have been tested, listed, or labeled "for that purpose".

Jerry,
Italics and underline are mine. If your interprtation of the code is correct, why do they continue to give the criteria for how it must be done? What you didn't underline and bold face was "adequate space." Since it doesn't say "by the manufacturer", is it possible that they were referring to the electrician leaving adequate space for that purpose? The electrician would then have to assure that the criteria underlined and in italics were met.

[Jerry Peck]

I did not underline or bold "adequate space" because I was highlighting the other words, which are usually missed when that is read.

This is the main content of that section:
"Enclosures for switches or overcurrent devices shall not be used as blah-blah-blah, unless blah-blah-blah for this purpose is provided."

The last sentence goes on to tell one how much space the wiring can take up. Both the wiring normally in the enclosure AND the wiring allowed *IF* this had space provided "for this purpose".

I.e., the total wiring fill must be within those limits set forth in the last sentence, however, just because the wire fill *is within those limits* DOES NOT MEAN that you can add more wiring using the enclosure as a junction box, raceway, blah-blah-blah.

Remember, that starts out by saying "Enclosures for switches or overcurrent devices shall not be used as ... " Remember that "shall not be used as" part. Plain and simple.

Then, however, it gives an exception to that statement "unless adequate space for this purpose is provided." Remember that "space for this purpose" part.

Those two 'remember' parts are key. "shall not be used as" "space for this purpose" and "is provided".

What it does not say is "shall not be used as" *unless the fill requirements set forth next are met*. That is how some read it, but that is not what it says. They skip right over that part which states "unless adequate space FOR THIS PURPOSE is provided".

[Thom Walker]

Thanks

[Brian Hoagland]

Is there not a code that states that pass through wiring (using the service equipment panel as a junction box) is a forbidden? This question is a great fodder for debate, my understanding on this issue is that wire junctions are allowable within the panel as long as those junctions serve only the functions of the panel and are not a part of another panels circuit run through (as a chase) to serve circuits not governed within the panel run through. I hope if any of you feel this is inadequate as a desciption you will comment and let me know.

[John Steinke]

I read the section differently ... as long as there is room, it's OK. There is a more specific prohibition for motor starters; had the committee wished to ban all such 'pass through' wiring, I believe they would have copied the wording of the other section.

Likewise, there are labeling requirements for when power from other sources ("foreign power") pass through an enclosure. I can't imagine 'foreign' power being allowed to pass through, but not a switch leg for a circuit that originates in that panel.