What is going on with this receptacle?

I'm in the process of doing some low voltage wire runs at my father in law's house and I noticed a 110V receptacle that has three lines coming out of it. As I understand, middle of run receptacles have two lines and end of run receptacles have one. I don't understand what is going on with this three line setup. I know that one of the lines is coming from the breaker box (with other mid-line receptacles along the way), and one of the others continues on to an end of run receptacle. The third line just goes up around the corner where I can't see. Any idea what this is? I suppose it could just go to another receptacle, but I was under the impression that could couldn't add to the middle of a line without a junction box.

 

As long as you don't go over box-fill, you can run as many wires to a box as you want. It's nice to keep receptacle boxes down to two pieces of 2-wire, but it isn't always practical.

 

While it is generally true that most original installations are done serially (from one outlet to the next), this is not always the case. Sometimes a switch loop is needed, and sometimes it is just easier to do in some other pattern.

However, when a circuit is added on to, the new line may well be added anywhere, wherever it is convenient and wherever the wire can be run the easiest.

 

_All_ receptacles need to be in junction boxes, middle of run or end of run.

If the receptacle is in the junction box, and if the junction box is not 'overfilled', then you can have as many splices as you want.

There are specific rules for 'overfilled', not simply 'stuff as many wires as will fit'; if you give us the dimensions of the box that the receptacle is in, and the gage of the wire, then we can tell you if the box is too full. Also if you search this forum for 'box fill' you will find out how to do these calculations yourself.

Finally, when you have multiple cables, they _must_ be spliced correctly. Devices such as receptacles can only have a certain number of cables terminated on them.

If the receptacle is being used as a splice, and it is a 'normal' residential receptacle with two screw terminals per side, then you can only use that receptacle as middle of run or end of run. If you need more cables spliced in that junction box, then you need to use wirenut splices and pigtails to the receptacle.

There are some receptacles that permit larger numbers of wires to be terminated on the receptacle. In no case should multiple wires be terminated under the same screw head.

-Jon

 

Jon,
I agree with your answer, although I'm curious why "If the receptacle is being used as a splice, and it is a 'normal' residential receptacle with two screw terminals per side, then you can only use that receptacle as middle of run or end of run. ".

Why can't it be the first receptacle on the branch circuit? I will assume a "normal" residential recept will not be on a multiwire circuit.

 

HandyRon,

You are quite correct, such a receptacle could be the first item in a branch circuit. I was simply using 'middle of the run' to include any case where a cable feeds to the receptacle, and then feeds from the receptacle, which would include the first receptacle on a branch circuit.

-Jon