In order to test an electrical circuit, add each wire of a two-wire circuit tester to the wire or outlet. If the circuit is on, the tester should display the voltage on the reader or light up.
Testing an electric circuit is useful for a couple of key reasons. It can let homeowners know that a circuit is truly shut off before they start working on wiring. It can also help them find faulty wiring and broken circuit breakers.
To use a circuit tester on a wire, switch the tester to the correct voltage type. Attach one of the tester cables to the wire and another to a grounding object. To use a circuit tester on an outlet, insert each wire of the tester into the outlet plugs. To test the circuit on a circuit breaker, touch one of the tester cables to a grounding object and the other on the breaker's terminal screw.