How To Use An Electrical Tester

An electrician’s best friend can be their electrical tester. Without one, electricity is all guesswork and is never the safe way to go. There are many different types of testers and they perform a wide variety of functions. For most applications a voltage tester is sufficient, but every once in a while, an electrician will need to determine continuity as well. For home applications, a voltage/continuity tester will be sufficient for any task. This article will explain how to use a tester in an effective manner. After all, if you do not know what you are looking at, what would it mean?

Any decent tester found today would be similar to this one by function, it may not look like this one, but it will work like this one. You will notice the big dial right in the middle. This dial is used for switching modes on the tester. There is an Off selection, Voltage, Amperage, and Continuity. You will also notice the red and black leads. These leads will be used for the voltage and continuity tests. The opening in the front will be used for amperage readings. The display, will return test results to the user, and there is even a hold button for those hard to see tests.

So, we got this tester and still do not know what to do with it. Let us use a receptacle in the room that is known working to work with. The first thing we would do is turn the tester on to the “V” (Volts) setting. Inserting a red lead into the left slot and the black lead into the right slot, the tester should read 115-130. 115 is quite low and 130 is quite high. This author’s reads 126 at home. Any reading other than this is cause for alarm and further investigation.

What is the amperage of the TV? Let’s find out. We will have the receptacle removed from the wall and hanging safely, with the TV plugged in only. Next, turn the TV on and set the tester to “A” (Amps). Slide the open jaw of the tester over the black wire, the display will change and you will now know the amps of the TV.

I wonder if this light bulb works. If this is an incandescent bulb, you can set the tester to “O” (Ohms), and find out. Place the red lead on the threaded part of the bulb, and place the black lead on the solder blob at the base. Making sure not to cross leads, you should hear a tone, indicating the bulb is still good for at least one more flash of light.

This should give you an idea of how to use a tester and what kind you should need as a homeowner. One can never be to safe when working with electricity and a tester is a great start to doing just that. Photos from Fluke Electronics.