Is it safe to have two power sources (meaning 2 sets of 12/2 wire) on one receptacle?
One set of wires goes to breaker #2 and another set of wires goes to breaker #7 but both 12/2 wire sets were hooked up into one receptacle.
Just curious why someone would do that.
Best Answer
Sounds like they messed up and accidentally made a "ring circuit".
It's possible to have 2 circuits legally on one receptacle (the 2 sockets and frame called a "yoke"). However, if you do have 2 circuits on a yoke, the breakers MUST be handle-tied with a factory provided handle-tie.
Otherwise a maintainer could plug in a radio and shut off circuits until the radio goes silent, then pull it out and get nailed by the other circuit.
A 2-pole breaker (that's a 2-pole NOT a duplex/twin/tandem) will also satisfy the requirement since its handles are tied. They're a lot easier to obtain than handle ties.
Generally, handle-tying implies that they will be on opposite poles of 240V service (i.e. 240V between the different hots). This is one of the very few cases where a handle-tie on a tandem would be alright, but they don't make any such thing, not least because it would be bad in any other application.