Safety first! You have to keep the electrical current on when you use the volt tester, so be cautious. Always wear rubber shoes or stand on a rubber mat when working on a control panel. Make sure the floor or earth underneath the panel is dry —not damp or wet. Water is an excellent conductor of electricity, and you don’t want to become part of the circuit. Wear safety goggles in case of flying sparks.
Get a voltage tester that’s rated for up to 500 volts.
These testers are available at most home improvement or electronic supply stores.
Remove the cover from the service panel.
You’ll see your circuit breakers (and they’re all clearly labeled, of course).
Always take safety precautions: Wear rubber shoes when you work on a control panel and make sure the floor underneath the panel is dry.
Touch one prong to the terminal screw on the breaker and the other to the ground.
If you decide to use a voltage tester, don’t touch a bare wire or the neutral as you’re testing. If you do, you’re in for a bit of a jolt.
Check the glow light on the tester.
If the light doesn’t turn on, there’s no power and the breaker is faulty. You’ll need to replace it.