How do you handle a lot of wires coming into a box?


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Old 08-22-15, 06:33 PM
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How do you handle a lot of wires coming into a box?

In my garage, I have the power coming into a central box on the ceiling with one always hot (for a garage door opener), and one switched (for plugged in shop lights) sockets. The box also branches off in three directions to other outlet boxes for low power devices such as hand power tools. Today I ran a line for a motion detector light to this box. I was in DIY electrician hell . There are only so many solid 12 gauge wires you can get onto the socket screw terminals and into wire nuts. I also had about 6 ground wires to deal with. There must be a better way! What is it?
 
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Old 08-22-15, 06:41 PM
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The box also branches off in three directions to other outlet boxes
One cable to the first box and daisy chain the other two from there.
There are only so many solid 12 gauge wires you can get onto the socket screw terminals
You can only have one wire per screw terminal. If more than one they need to be pigtailed.
I also had about 6 ground wires to deal with
They should be pigtailed and connected to the box if it is metal.

Bottom line you may need to add a box extension and if necessary use gray wire nuts.
 
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Old 08-22-15, 07:25 PM
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You may find the push in connectors helpful.

Better routing of the cables will help. Larger boxes will also help.
 
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Old 08-22-15, 09:28 PM
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You can only have one wire per screw terminal. If more than one they need to be pigtailed.
That is true IF the wire wraps around the screw. There ARE devices (more expensive and better quality) that have a pressure plate under the screw head and the wire is inserted from the back under the pressure plate and then the screw tightened. These are called back-wired, not to be confused with back-stabbed which is an inferior connection. Back-wired devices may have one wire on each side of the screw shank for a total of two wires for each screw.
 
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Old 08-22-15, 10:28 PM
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Thanks for the suggestions. Although I eventually got it to work I do want to make cleaning it up a future project. Daisy chaining it would not be practical at this point, but I like the idea of a bigger box. My plan now is to remove the two outlets from the box and put them in a separate box. That should leave plenty of room in the existing box to just use it as a central distribution box. I was going to ask if it would be ok to pigtail in two levels, meaning that if I had 6 wires to bring together, pig-tailing 3 sets of 2, then pig-tailing the 3 sets together, but while Googleing around, I found a product called Push In Connectors. They look like just the ticket to doing a neat job. The 6 wires in my example above would just be pushing into a a 6 port or greater connector.

Edit - Oooops, sorry pcboss, I see you posted the entire fix a couple of hours ago.

Tool Review: Ideal In-Sure„ Push-In Wire Connectors « Home Improvement Stack Exchange Blog
 

Last edited by JeffLeites; 08-22-15 at 10:30 PM. Reason: Saw the answer in a reply
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Old 08-23-15, 01:32 AM
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The Ideals are a nice product. The contact area is much better than a backstabbed device.
 
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Old 08-23-15, 05:10 AM
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If too many wires want to go into one wire nut then yes, you can split them into two groups with a jumper (pigtail) in between. For bare ground wires, they make (green) wire nuts with a hole in the small end so if one of the wires is long enough, it can be the backbone for two wire nuts end to end.

Two wires can go under one screw only if they don't touch each other and the terminal parts are shaped so neither wire can possibly slip out sideways slightly before the screw is tightened.
 
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Old 08-23-15, 05:17 AM
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Count one point for each non-ground wire end entering the box. Count one point for all the ground wires. No points for pigtails (short lengths wholly within the box). No points for wire nuts. Two points for each switch or receptacle unit. One more point if there are cable or conduit clamps protruding into the box. Total times 2-1/4 to get the box size cubic inch requirement for 12 gauge wires.
 
 

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