Can I replace 15 amp outlets with 20 amp outlets to run a new 20 amp circuit for my portable AC unit, considering the aluminum wiring in my house?
Asked by Lubomir Simić 
1 month ago
Last Updated: November 13, 2024
Hey electricians, I need some advice. Last summer, during a heat wave, I got a portable A/C unit that keeps tripping the 15 amp circuits I’ve tried it on. I’m considering adding a 20 amp circuit for it, but I’m also in the process of replacing the aluminum wiring in my house. The new 20 amp circuit with 12/2 cable would run past some 15 amp outlets (freezer, lamp, TV) on aluminum wiring. Can I replace those outlets with 20 amp ones and add them to the same circuit as the portable A/C? Thanks for any help!
When you’re looking at the amp draw on your AC and freezer, it can help determine if the 20 amp line is sufficient. Without knowing the specific draws of each, it’s hard to say for sure!
I’m currently in New Jersey and appliances like refrigerators, microwaves, etc. need a dedicated circuit. What other devices are connected to those 15 amps when the air conditioning is on? You can’t simply switch a 15 amp with a 20 amp, the wire gauge needs to be correct.
In short, no, but the long answer involves some math. You can find the amperage and wattage information on the nameplate of the AC unit, which is the most reliable source of information.
You might want to consider giving the freezer its own circuit, but I’m not sure if that’s required by code. Running the numbers, as suggested, is crucial. If you’re already installing a new circuit near the freezer, it might be worth adding another one just for the freezer and other appliances. I’ve heard that duplex 15 amp receptacles can be used on 20 amp branch circuits, although 20 amp receptacles are likely the safer choice. Double-check the code to be sure, as I’m not an electrician, but I’m quite confident in this information.
When you apply for the permit to perform this work, the inspector will review it. They might not be able to inform you in advance about what will meet the requirements.
For a dedicated 20 amp circuit, try to have only one outlet connected to it if possible. While you can link the rest of the outlets to the 20 amp circuit, it somewhat defeats the purpose.