How can wires be tested to tell if it's hot?

Electrical wires are one of the most dangerous items in any environment. Whether you’re trying to fix an outlet at home, or running a new wire in the workplace, it is important to learn how to stay safe. One of the many things that makes working with wires so hazardous is the fact that it is impossible to tell if a wire is hot or not just by looking at it. This can lead people to touch a wire with a live current, resulting in a shock or electrocution. Fortunately, it is not difficult to test wire to see if it is hot, as long as you know how.

Testing the Wire for Current

The first step in any job involving electrical wires is to take precautions to ensure the wires are disconnected from any potential power source. It is never ok to just assume that a wire isn’t hot because you flipped a switch or thought someone else did. The following are some simple things you can do to tell if a wire is hot:

  • Turn it on & off – If the wire is hooked up to some type of device, try turning it on. This is the simplest way to test the system. Just note, however, that even if the device doesn’t turn on, that is no guarantee that the wire is not hot. It is just a first step in the testing.
  • Trace the wire – When it is possible, you can trace the wire from the area where you will be working back to the source of electricity. Once there, disconnect it from the source, and lock it out so it can’t be energized again. This will ensure the wire is not hot and remains safe while you are doing your work.
  • Perform a test – In many cases it is difficult to trace a wire from one end to the other. When this is the case, you can test a wire with a current tester or a voltage meter. This is a simple device that you touch to a wire and it will alert you if there is any current. Make sure to test every wire you will be touching to confirm they are all inactive.

Learn Wire Standards

Another helpful thing you can do when it comes to testing if a wire is hot or not is to understand the wiring standards that are used. Taking the time to learn what color wires are supposed to be hot, which ones are neutral, and which ones are ground, will help you to know how to proceed safely. Of course, you can’t be certain that the person who installed the wires followed the standards, so always perform additional tests before touching any wires.


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