\u00a9 2023 wikiHow, Inc. All rights reserved. We can also use it to find hot wire. If there is voltage present, the detector will make a beeping sound. Then for the real test, put on your switch and do the measurements again. Wear safety goggles to protect your eyes against electrical flashes, especially during electrical testing. The red wire is a phase 2 hot wire, and the white wire is neutral. Dont let the probes and the wire collide with each other. wikiHow is where trusted research and expert knowledge come together. Within this function, several numbers indicate the different ranges of voltage. However, in some situations, both wires are black, but one has a white stripe. The blue wire is known as the neutral wire. 1. . If the lamp lights, then the wire is live/hot. Even though codes regulate wiring, there's no guarantee that your wiring follows those codes. output wires. If youre a first-timer, you should work on electrically dead systems. Identifying a neutral wire as others for a secure connection is essential.