Why would a standard duplex outlet have seven wires ( including the ground) connected?

Question

In attempting to replace an outlet in one of the bedrooms we discovered that instead of the standard two hot and two neutral, plus one ground we discovered six wires plus a ground. There appeared to be three hot (two on the lower outlet), three neutral (also two on the lower) and a standard ground wire. As far as we know it is a continuous power outlet and is not connected (and never has been) to a switch. The house was built in 1968 and the previous owner did a number of DIY "improvements". We left the outlet as it was since we had never encountered anything like that before and couldn't find any guidance on the matter. Anyone see this before, got any advice?

Answer 1

Its a normal situation.  The box is functioning as a Y-connection with one hot in and two hot out to other locations.  There is nothing wrong with that.  However, you are not allowed to have two wires under one s***w (though, really the risk that this would cause would be very minimal) so you should actually pigtail the connection.  If the box is too small for six wires (you only count hots and nuetrals, not grounds) and three connectors then an alternative is to use the 4 s***w terminals and two 'push-in' type terminals.  Many people dislike these push in connectors, but lets face it, if they were not safe, they would not be used.  They actually put a similar level of pressure on that a s***w connector does.  I suspect that once the 'fear' of them fades, they will fully replace s***w connectors.

As per only having one ground, its quite possible that some of the wiring is old enough that it was made without a ground.  If you can replace the wiring (right through to the next plug) then it would be good to do that (assuming that you have a ground back to the panel, however, if not you can just go without the ground - which is a greater risk than having a grounded plug.