Using a Voltage Tester

They’re the cheap easy way to test any circuit in your home and the two pronged tester is available almost everywhere. Where ever you find the tester and whatever brand of tester that you finally decide to use, make sure to test it out on a circuit that you know is energized so that you can determine if the tool is broken or not.

One of the first places that you might want to try the tester out is on a receptacle. To do this, you should grab the tester by the insulated handles and insert the probes into the receptacle slots. Never touch the bare wires of the tester probes. If the tester lights up, there’s voltage present.  If the tester is broken or the receptacle is loose, the tester might not detect any voltage in the box.

To check further, unscrew the receptacle cover plate and the screws holding the receptacle in. Pull it out from the wall and touch the probes on the tester to the screws on the opposite sides of the receptacle. Then touch the probes to the bare wire ends. Finally, touch the probes to the black wire ends and to the metal box.  

There is another way to test fixtures. Unscrew the fixture in much the same method as the one described for testing receptacles. If a switch controls the fixture, test as per the method for testing switches. To identify the circuit that controls a particular switch, turn on the fixture it controls and get someone flip the breakers until the lights go out. If that test is inconclusive or you aren’t sure the switch is operable, remove the cover plate and the two screws holding the switch to one box.  Test the lead wires running to the switch—be careful not to touch the screws on the sides of the switch or the wires leading to them.

Remember that switches interrupt hot wires, so apply the tester probe to each screw on the switch as well as any group of wires together. There are professional testers that are available to electricians as well, and there are scores of these professional testers to choose from, some of which can coast as much as hundreds of dollars. These are not necessarily the domain of the homeowner. The ones that are most common for the handy man at home fall into a few different categories.

Neon Voltage testers are inexpensive and versatile. The better versions of these testers have insulated handles. One of the more common types is the shirt pocket tester that gives a reading without even touching a conductor. All you need to do here is touch the tool’s tip to an outlet. Multi-meters offers precise readings on multiple scales which can be selected beforehand. Whichever one you decide on, make sure that you know how to use it properly before you attempt to try it on anything that’s live.