Thread: how many spliced circuits should be in one junction box?

1. how many spliced circuits should be in one junction box?

I inspected a home yesterday and found this. I am sure you guys have seen this before. Is this too many circuits (unlabeled to boot!) in one junction box?

2. Re: how many spliced circuits should be in one junction box?

No. Not too many.

They don't need to be labeled.

There are a lot of wires bundled in thru one hole in the panel box. That one I can't be sure about.

There might have been a fire and a lot of cables had to be repaired, or a breaker panel was moved. Sometimes there has to be a complicated repair with a lot of splices.

3. Re: how many spliced circuits should be in one junction box?

I see this quite often when old panels are abandoned and made into junction boxes. They connect new feeds and pull them to the new panel, some times they replace the old panel with a junction box also. I would guess that's what you looking at. It's acceptable even though it looks like a rats nest.

4. Re: how many spliced circuits should be in one junction box?

Most electrical boxes are inscribed with the volume expressed in cubic inches. Electric code tells you how much volume various size wire, the grounds, devices etc. require. You can find this info as "box fill".
Then it is a math exercise. Add up required space and compare to box marking.

5. Re: how many spliced circuits should be in one junction box?

Looks like an extra large Jbox. The wires could be organized a bit better.
Any concern about what looks like unprotected and exposed romex popping
out of the wall and going to an external switch or outlet box?

6. Re: how many spliced circuits should be in one junction box?

In itself it looks like it is ok, but as messy as it looks it might indicate an amateur did it. Normally an electrician is a little more organized and makes them look a little more orderly. If it were me I would be looking at other areas of the electrical to see if there are questionable practices involved elsewhere.

I did a small commercial the other day and one by one the system may have been alright, but I could tell that every time a new retail business moved in to the building, the electrical was modified. Luckily there was one breaker that was tripped and would not reset so I easily had a reason to recommend an Electrician be consulted and make that repair, but also reported that because of so many modifications over the years an electrician do a more thorough/full Inspection of the complete system and make any needed repairs.

7. Re: how many spliced circuits should be in one junction box?

Originally Posted by Sherrie Lyle
Is this too many circuits (unlabeled to boot!) in one junction box?
The code requires labelling of the circuits in the main and any sub-panel. This is used as a junction box so it is a "through" connection, there is nothing to "trip" here and no labelling is needed. Also, if an electrician ever changed the main circuits, say exchanging circuit 11 for 13, then jbox labels would be incorrect.

As to how many wires one can put in a Jbox, well when I was working in commercial electrical I found it VERY hard to have enough room for the number of wires allowed by the size of the box with connectors when wire is cut to proper lengths etc. Especially true if romex with ground is used in residential. This means that there is a neutral and ground for every hot lead instead of for every two/three as in commercial. Fills a box quickly!

8. Re: how many spliced circuits should be in one junction box?

Originally Posted by Dirk Jeanis
As to how many wires one can put in a Jbox, well when I was working in commercial electrical I found it VERY hard to have enough room for the number of wires allowed by the size of the box with connectors when wire is cut to proper lengths etc. Especially true if romex with ground is used in residential. This means that there is a neutral and ground for every hot lead instead of for every two/three as in commercial. Fills a box quickly!
Proper planning of the circuit wiring will result in the proper size box being utilized. I worked in commercial electrical for many many years and never had an issue with box fill.

9. Re: how many spliced circuits should be in one junction box?

Originally Posted by jack davenport
Proper planning of the circuit wiring will result in the proper size box being utilized. I worked in commercial electrical for many many years and never had an issue with box fill.
we never ran out of room relative to the number of conductors allowed, it is just that a box can be pretty full even when more conductors are allowed.

We did one VERY large job and made arrays of jboxes smaller the farther from the source…most had 1 to 4 full round houses left in the box all the way back to the main, fully labelled to circuit numbers etc. We knew that for the next year we wold be called back to install equipment and circuits regularly. Made those jobs a lot easier.

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