How to Use Voltage Testers

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Things You'll Need

  • Safety glasses

  • Voltage tester

  • Electrical safety gloves


If testing a high voltage device or receptacle, please contact an electrician.


Turn the electricity to the outlet, switch or device is before using the voltage tester.

How to Use Voltage Testers. If you're going to do your own wiring in your home, one of the most important tools you could ever have is the voltage tester. The testers are the best way to determine whether the electricity is off or on in the house. As always, work safely, and do your homework when it comes to choosing the right type of tester for the wiring job you're going to do. Read on to learn more.


Step 1

Determine whether the electricity is on or off by using a two-prong voltage tester. If checking using an outlet box that has not been screwed into the wall yet, take the red lead wire of the voltage tester and place on one of the box screws on the side of the outlet.

Step 2

Place the black lead wire on the other screw. When checking an outlet that is already attached to the wall, place the red lead wire into the outlet and the black lead wire on the screw on the top screw of the outlet plate. Either way if the light in the handle of the tester lights up, that box has voltage.


Step 3

Test a receptacle using a plug tester. These testers have three lights on the end and tell you if there is voltage and if the receptacle is wired correctly.

Step 4

Use the right size of voltage tester. There are various sizes ranging from hand held, commonly used in testing electricity in homes, to the larger sizes that are more common for high voltage testing commonly used for commercial purposes.

Step 5

Test using a non-touch voltage tester. This tester looks like a pen with a see-through tip. Use this tester the same way probe testers are used--except you use the tip instead of a probe. The tip lights up when there is voltage present.


Step 6

Test dryers and stoves when they are not throwing heat with a voltage tester, but use caution. It's best to test for voltage by testing across either the fill valve, switch or thermostat to the appliance. If the tester shows 220/240, the thermostat or the circuit is open. If the tester shows zero, the thermostat or circuit is closed.