How are live wires identified?

Electrician checks live wire equipment using device

When taking on any type of project involving an electrical system it is critical for safety to know whether the wires in the system are live or not. It is impossible to tell if a wire has current going through it just by looking at it, which is one of the things that makes them so dangerous. In addition, if you try to check if a wire is live by trying to quickly tap it with a finger or other item, it could result in a serious shock. With this in mind, it is a good idea to learn how to identify live wires before you start any project.

Current Checking Devices

One of the easiest ways to know if a wire is live is to use a voltage tester or a current checker. These are simple devices that you can touch to any wire, and it will tell you if there is electricity running through it. More advanced versions of these devices will tell you exactly how much current is on the wire as well as other information. Anyone who regularly works on electrical systems should have this appliance available to them.

Remove Sources of Electricity

Unplugged cable from wall

Even if you confirm a wire is not live using the above-mentioned appliance, you also need to be certain that it won’t become live while working on it. In order to prevent this from happening, it is important to remove the wire from its source of electricity. For example, if you are working on some type of home electronics, simply unplugging the device will help to minimize risk. This is also a good way to know that the wires are not live.

Keep Alternative Power Sources in Mind

Unplugging a device will effectively ensure that a wire is not live in most systems, but that is not the case in all situations. Many devices, especially in the workplace, will have a backup power outlet. Some devices, for example, have a backup battery or capacitors that could still have an electrical current.  For this purpose, it’s important to test the wires, and wear proper personal protection equipment, whenever working on this type of system. 


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