Electrical Wiring in the Home/20 amp outlets


QUESTION: Hello, I have two 20amp 125v dedicated outlets in my house and I've noticed that if I plug any fan into these outlets they run slower than if I use them on the regular 15 amp outlets. I've tried fans with polarized plugs and without. I have replaced one outlet with a new one, same problem. Weird. Why would this occur? Is there something in the construction of that weird T shaped hole on the polarized side that only works best with a horizontal plug blade? Are the 20 amp breakers not really 20 amps? Are they wired backwards? (I doubt it) Any help would be appreciated.

ANSWER: Unlikely and certainly unrelated to the device.
Perception is not evidence.
What are you using to measure the fan's rpm?

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QUESTION: I'm using my ears, and my wife's which tell us that the fans are running slower at these outlets. Not a lot, but there's a difference. Can you perhaps narrow down the possible causes for this?

What you think you hear is possibly cause to investigate.
Once you decide to do that you need an ammeter, a voltmeter and an rpm meter.
Photos or videos of the tests would probably be useful as well.
Create a table with the results of your measurements at the various locations.
Then there is something to evaluate and discuss.

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This site answers questions related to home electrical wiring, home wiring, general electrical help,and other electrical questions related to aleternating current (AC). You can find help on the National Electical Code, home electrical issues, wiring electrical outlets, installing lighting, electrical grounding, and general electrical help for do-it-yourself projects not require an electrician. If you do not see your home electrical wiring question answered in this area then please ask your electrical wiring question here

Electrical Wiring in the Home

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Robert Wilber


Licensed Philadelphia electrician serving Delaware, Chester, Montgomery and Philadelphia County in Pennsylvania. I install and repair residential, commercial and industrial wiring and lighting. Troubleshooting and repair of problems that stump other people is my favorite. I am willing to help people figure out why things don`t work. I understand motor controls, transformers and machine wiring. I do not teach basics to novices or do free design work.


Experience in the area I have 44 years experience in residential, commercial and industrial electrical construction and repair, 480 volts and below. This is not to be confused with one week repeated two thousand times.

44 years experience in residential, commercial and industrial electrical construction and repair

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