Reverse Polarity code When Plugging in at Home

wildtoad wrote:
Call an electrician and have them check the wiring.

This can be done before calling an electrician.

Go to a big box hardware store and buy a no-contact voltage tester. They are not expensive. That will tell you exactly which slot on your 30 amp outlet is hot. You can then tell if the outlet is wired backwards. With the round slot at the top, the hot slot should be lower left.