How to Check If a Wire Has Power

David Lipscomb

Anyone attempting electrical maintenance around the home must have a way of determining whether an AC wire has power. Often, the breaker box is not convenient to access mid-project, especially when standing on a ladder with a handful of tools.

Checking a wire for power is fast and easy with the right tool.

Fortunately, a simple battery-operated device helps the do-it-yourselfer quickly and reliably detect power on a line.

  1. Activate the electric power detector by turning the top knob, or pressing a button.

  2. Test the detector on a known hot outlet or wire, by placing the tip of the detector in the outlet or on the wire. Observe the light and sound at the end of the detector to verify the unit is operating properly.

  3. Head to the wire that needs to be checked. Set the tip of the detector against the wire. If a light and/or beeping sound activates, the wire is hot and the breaker must be turned off.

  4. Check all of the other wires with exposed metal conductors, if you will be working among them.


Choose a quality detector. AC power can be dangerous, and not something left to chance.

Check out this related video.