Every electrical current generates a magnetic field, so a non-contact voltage tester can detect current in a conductor ...

On the other hand, he does mention using it to shut off ... Making a device to test an RCD is easy; a resistor between hot and the protective ground circuit would do. [Callan] over-engineers.

This is the first 90-degree foldable circuit probe tester in the world. Designed with both professionals and DIY enthusiasts in mind, this latest addition combines advanced features with practical ...