How To Use a Voltage Tester | Ask This Old House

Summary by Krater

This Old House demonstrates how to use different types of voltage and circuit testers to determine if electrical receptacles are energized and properly wired.

From the video

Answers: How do you use a voltage tester on electrical outlets?

• Contactless voltage tester
• Digital multimeter
• Plug-in circuit tester
• Receptacle wiring polarity
• Identifying energized wires

What it concludes

• Contactless voltage testers are easy to use for checking if something is energized, but they can occasionally give phantom readings if placed in the wrong spot.
• A plug-in circuit tester with three prongs will accurately indicate reverse polarity when the black and white wires are switched on the receptacle.
• An incorrectly wired receptacle can still power appliances and lamps, but it presents a serious safety hazard.
• If a lamp socket is wired with reversed polarity, the shell becomes energized instead of the center pin, creating a shock hazard.