Electrical – All outlets on one 15-amp circuit, need AC unit

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The central AC in our apartment is not working effectively in the summer; we are running the AC continuously for 14 hours a day to keep the temperature below 80 degrees. As you can imagine, our electric bill has become a huge problem.

(Edit: Please note the maintenance staff are incompetent and management doesn't care about our problem at all -"getting the central AC fixed" is not an option, if it's even fixable)

I bought a used portable AC unit (around 11,000 BTU, rated at 12 amps) and plugged it into an arbitrary outlet near a window, because I was always able to do so with a similar AC at my parent's house. The portable unit worked great for a couple of minutes and then tripped the circuit breaker, which also shut off my computer.

After a lot of testing I have determined that all of the outlets in the two bedrooms and in the living room run off a single 15-amp circuit (which was 'helpfully' labeled "lighting" in the circuit box). This rules out every outlet that is within reach of a window. There are two circuits labeled "plugs" in the circuit breaker, but AFAICT they aren't connected to anything (unless they're for the outlets in the kitchen).

Obviously because it's an apartment I can't do anything with the wiring, and I can't use an extension cord on an 11,000 BTU AC… Am I screwed here? Is this typical for an apartment with central AC?

The full set of circuits is (as they are labeled):

  • Central AC: 2x30A
  • Central Heat: 2x30A
  • Bathrooms: 2x15A
  • Plugs: 2x20A
  • Lights: 1x15A (again, this actually covers outlet in 3 rooms, there is no overhead lighting)
  • Garbage Disposal: 15A (nowhere near a window)
  • Dishwasher: 15A (nowhere near a window)
  • Electic Range: 2 x 40A (oven/stove)

Best Answer

We resolved the problem with the portable AC by purchasing a heavy-duty, 15-amp, 12-gauge extension cord and running it from the bathroom to the AC by the window. Since the bathroom is on its own circuit, the AC does not trip the breaker. A big thank you to those who suggested this in the comments.

Ironically, management has decided to replace our central air conditioner after I discovered mold in the unit, and their subsequent inspection also revealed it to have a serious Freon leak.