wiring a branch circuit????

I have grouped the ends of 8 each 12-2 w/ground wires in the center of my attic that feed various 15amp receptacles (the longest wire being less than 20’ in length).

My questions are:

1- What gauge main wire will I need to feed feed these wires from the breaker box that is less than 20’ away?
2- What amperage breaker will I need?
3- What type of junction box is required to connect the larger gauge wire to the 12-2 wires?

Thank you in advance for any info :shock:

20 A breaker max.

You have to protect the 12 gauge wire and it is only rated for 20 A.

You have a larger problem with the size of the junction box and the wire nuts needed to connect it all.

Each junction box is rated for a maxim number of conductors and wire nut connections.

Isn’t there a junction box available with a bus bar that I can use?
I also understand that I don’t ground this secondary box?

any idea what size wire I need to feed the junc box?

Agreed! You should call in a electrician for this work if you don’t have this info.

can’t afford one if there is someone here knowledgeable with the facts I’ve stated.
Should be fairly straight up info??

You are not understanding something.

The 12 gauge wire MUST be protected by no more than 20A protection.

Hire or find someone who understands before you hurt someone.

EVERY metal box must be bonded to the GES.

OK thanks for the info.

Why am I envisioning multiple pigtails in that proposed box?

I hate to say this, but I hope that is his home, and not that of an innocent!!

If you dont have the money to hire a professional, dont run the circuits. You likely will just end up hurting someone.

Don’t forget the duct tape.

Thank you again Mr. Larson and Mr. Pope for the useful information.

Sorry guy but you’re in over your head. You’re looking to run a larger conductor/cable with larger than 20 amp OCPD to this box and then splice onto your 12/2 circuits. This would involve tap rules and other stuff that is way beyond the scope of this forum.

To maintain the professionalism of this site I took the liberty of reporting the unnecessary posts such as “I hate to say this, but I hope that is his home, and not that of an innocent!!” and “Don’t forget the duct tape”. These could be construed as “Taunting” as described in the site rules. The duct tape comment was obviously made to ridicule but the “I hate to say” comment was a direct afront to the safety of myself and my family directed to other than the initiator of the thread.

The guy at Home Depot tells me that I can run a 12-2 wire with ground from the main box to a plastic junction box and wire nut no more than 4 each 12-2 wires to it. Sound plausible? 20 amp breaker in the main box.

I have learned that I’m in the wrong place for the answers I’m seeking. Thanks again to those that offered information and to the others that discouraged me from doing the work myself in the name of public safety.

I am MORE that knowledgeable and qualified to answer your question. The problem is that what you want to do is absolutely the wrong way to achieve what you want. But to give you the short bus answers since this whole set up is a “short bus” way to do it is you need (and can only feed) a 20 amp Breaker and 12 guage wire to feed this mess. The Junction box will need to accommodate and have the proper box fill capability of all those
12 wires ( I don’t have the time to calculate that for you right now, go get an 8x8x 6" Plastic J box that will be more than sufficient and you wont need to worry about grounding it since it is plastic. Then when you are all done, Make sure all of your smoke detectors are working and you are all paid up on your home owners insurance.:shock:


I hope you reported me to the electricity police. No one else will listen.:wink:

The term GROUP in your orginal post makes me not want to assist you…sorry. oh…FYI…I am an electrician and darnn right I dont come cheap madam homeowner. Any advice given to someone clearly unable to understand the basic concepts will open yourself up to liability…have at it everyone.

No mention of Box Fill, Bundling and so on…Sure hope their home owners policy is current.