J Box Question

Hi, my panel box currently has 13 NM cables entering it. They are all older white 12/2 NM and are quite stiff without much flex to nail them to the plywood that the panel is mounted on because there was not enough slack left from the original install. I want to cut back all the cables and mount a large junction box (or two) and then run all new spliced 12/2 NM that is more flexible and can be stapled neatly above the panel box. I am confident, able and respectful about working with the box and the breakers. I guess my question is this: is there one large j box big enough to buy for this project (to hold the 13 cables) and question #2 would be where can I find cable clamps connectors to hold 2 cables at a time. Most of my present cables are doubled up inside of cable clamps that were made to clamp a single cable. Unless this is acceptable to do, I would prefer using the double clamp connectors. My local depot store does not carry these double clamp connectors. THANKS.

 

My first question is why do this at all? If the NM cables reach into the panel box and are adequately fastened with cables clamps then your wiring is just fine.

 

Check my math.
Your box size is based on the number of conductors entering:
13 cables * 2 conductors per cable = 26 conductors entering
26 conductors entering need an equal number leaving so ...
26 + 26 = 52
All grounds count as one so
52 + 1 = 53 conductors
12 AWG wire volume required is 2.25 cu. in. per conductor so
53 conductors * 2.25 cu. in. per conductor = 119.25 cu. in.

Plus leave yourself some space for additions.

This size box would be available at an electrical supplier. Measure the space available and see what they've got. I've used a gangable box, but if you do that make sure you can find the right cover first.

Many of the larger boxes will not have prepunched holes. For cutting holes use a punch, a sheet metal bit (unibit etc.), or a holesaw.

Supplier should have the right clamps too. Seems to me I've gotten NM clamps from big boxes that are rated for 2 cables, but I don't do much NM.

You might find it neater and easier to use conduits or combine multiwire circuits instead of using NM to get from the j-box to the panel. You'll have to check the local code for this one. The NEC limits the number of conductors for separate circuits that you can put in a raceway, but here the state code excludes that provision.

 

Hi ibpooks, so then is it ok to leave the cable clamps that have more than one cable passing thru them alone? the reason for this thread came about as a result of my home insurance adjuster/inspector coming because of a policy renewal and upgrade. He was the one who told me that my NM's entering my panel looked like "Half cooked spaghetti" and that the 2 NM cables passing thru one clamp ( IN SEVERAL KNOCKOUTS) connectors was against code. I had no problem leaving as is.....I was just seeking advice per the insurance companies suggestion. THANKS.

 

The inspector is ill-informed.

 

The "half cooked spaghetti" he refers to has nothing to do with proper wiring, and shouldn't enter into his realm of expertise. It may be a sloppy job, granted, but as long as they are not compromised, he needs to go back to his office and push paper. You may, in splicing the wires, compromise the entire situation further, so if it ain't broke don't fix it.

 

Tell mr bozo "inspector" to quote a code verse to support his claims or shove off.
I can't stand these wannabe officials who have only half a clue and get paid very good money to be right only part of the time. Imagine if we all could be right only part of the time? And have no one to be accountable to?
Geeze!

 

All that figuring for nothing! Oh, well. Maybe not:

Insurance companies are not government. The inspector is not there to enforce a code, he is there to set and enforce terms of a prospective contract. One would expect the code to be part of the foundation of their requirements, but they can set terms above and beyond that, too.

If the company has a requirement that wiring be "neat" or whatever they call it, then as long as they enforce the policy consistently, you can disagree with them, appeal, and ultimately find another insurer, right?

I agree that the company inspector should be able to quote chapter and verse, not necessarily from code, but from the underwriter's requirements or the contract. I also agree that it's better to leave the wiring as-is since based on the descriptions it's only an aesthetic issue.

If the inspector can't provide documentation to back his opinion, respectfully discuss with your agent and seek a ruling or opinion from a supervisor.

 

Thanks to all....I'm leaving it as is!

 

Imagine if we all could be right only part of the time? And have no one to be accountable to?

That's called politics!