My house (built in 1953) has a number of electrical inconveniences, including the fact that the same circuit that powers the outlets in the living room also powers many other disjoint locations throughout the house, such as all the lights and outlets in the basement, outlets in the back porch, closet lights and the entire second floor (!)

The previous owners had installed a built-in wall A/C unit in the living room that used a dedicated 240V circuit (probably installed in the 80s). When we removed the wall A/C, I disconnected that circuit and used its breaker slots for a new dryer. I left the wires in the wall, and would love to install a new duplex grounded outlet in its place.

My dilemma is, though, what circuit should I use to power the new outlet?

  • Using the same circuit as the other outlets in the living room would make the most logical sense, but it would further contribute to the potential overloading of that single circuit. Also I would have to find a way to splice into that circuit inside or near the breaker box, where the existing wires already terminate.
  • Using another existing circuit would be less prone to overload issues but would be confusing when the breaker is tripped or off for maintenance. I would also still have to solve the splicing issue.
  • Adding a new circuit just for this outlet is possible; I would have to buy a new tandem breaker since the box is full. It seems a little silly, though, to have a dedicated circuit just for a single outlet in the living room that may only have a floor lamp and a laptop charger plugged into it.

1 Answer 1


IMO it makes absolutely NO sense to use an existing circuit, especially considering how taxed they are. As long as your panel will accept tandem breakers what is the issue? Also, with a house of this vintage I highly doubt the wiring is grounded, which you cannot extend. And do not assume if the wiring is old AC/MC cable that it is grounded, much of it from that vintage is not, regardless of the metallic sheathing. The only metallic wiring like this that can be used as a grounding conductor is that with the think aluminum bonding strip running along side the insulated conductors. Besides, you never know what you might use this new receptacle(s) for. Don't think you'll never use it for anything more than a laptop charger.

Also, you re-purposed the old A/C circuit for a dryer?? Was it at least 10/3 cable? If not you have a non-complaint and potentially dangerous circuit if used for a 120/240V electric dryer.

  • If it isn't inside of a metal sheath of some kind, it may have a weaved hemp sheath that is likely deteriorating. Commented Jul 17, 2014 at 3:31
  • The wiring to the former air conditioner is modern 12/2 romex, with a grounding wire, so there's no concern there. Also, the dryer was wired by an electrician; it was only the panel slots that were re-used for the dryer.
    – kgutwin
    Commented Jul 18, 2014 at 13:33

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