How to test electrical outlets for polarity

Written by c.l. rease
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How to test electrical outlets for polarity
Polarity dictates the safety of an electrical socket. (Stockbyte/Stockbyte/Getty Images)

Properly wired electrical sockets provide power without causing damage to electrical equipment. The polarity of an outlet changes when the hot and neutral connects of an outlet reverse. A reverse-polarity outlet will supply the proper power to a piece of electrical equipment, but it can damage the equipment over time. Detecting and correcting reverse-polarity outlets ensures the safety of your electronics and the efficiency of your home's electrical system.

Skill level:

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Things you need

  • Straight-plug outlet tester
  • Masking tape

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  1. 1

    Turn on the power to the outlet.

  2. 2

    Plug a straight-plug outlet tester into the outlet. Check the circuit breaker or ground-fault circuit interrupter connected to an outlet if the lights on the tester do not light up when you plug in the outlet tester.

  3. 3

    Compare the lights shining on the tester with the label indicating the functionality of the outlet. Place a piece of masking tape on the outlet if the tester indicates the outlet has reverse polarity.

  4. 4

    Move around the area testing one plug on each outlet of your home. Mark each reverse-polarity outlet with a piece of masking tape.

Tips and warnings

  • Turn off the electricity when fixing reverse-polarity outlets.
  • Hire a certified electrician to correct reverse-polarity outlets marked with masking tape if you do not feel comfortable working with electricity.

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