If you are starting a project involving an electrical system, you need to make sure you know what each wire is so that it can be safely hooked up. While all electrical wires should be treated as if they were live until you can prove otherwise, it is the hot wire that is actually bringing the current to the device in question. Because of this, you need to take extra precautions whenever working with the hot wire. With this in mind, you need to know how to identify which wire is hot.
Wire Coloring Standards
The easiest way to determine if a wire is the hot wire is to look at the color. Almost all systems will follow the wire coloring standard, which says that hot wires should be black. If you see a black wire, it will almost certainly be hot, and should be treated as such until you can prove that this is not the case. Black wiring has been used for the hot wire for many decades now, so it is unlikely that you will run into an exception to this rule, unless the system was improperly installed.
Testing the Wire
If you have reason to believe that the person who previously worked on that electrical system didn’t use the proper color wires, you can always test them to be sure. To do this, remove the wire from the power source, and separate each of the wires at the end so that they are exposed. Restore power to the system, and then touch your multimeter or other voltage checker to each of the exposed wires. In this test, only the hot wire will have an electrical current on it, so you will know for sure that it is the hot wire. If you find that you have a hot wire that is not black, it is a good idea to replace that wire with one that is black so anyone working on the system in the future won’t run into the same issue. Following wire color standards is an important safety step that should always be followed.
- How are neutral wires identified?
- What’s the difference between a positive and neutral wire?
- How can wires be tested to tell if it’s hot?
- How do wire color codes improve safety?
- What color(s) are used for ground wires?
- What is a phase wire?
- What is the gray wire color used for?
- What are AC power standards?