Testing for Electricity

Testing for electricity is fairly easy and safe as long as you are careful. This article will show you where to put the test leads on outlets, switches and light sockets and plain old wire but does not explain how electricity works. Electricity is dangerous, having at least a basic understanding is a good thing. If, in the course of your project, you feel uncomfortable with any aspect: STOP and call an electrician. One more note, make sure that your hands never touch the metal part of the test leads. Testing Exposed Wires: This is the easiest. Simply touch one lead to one wire and the other lead to the other wire. You can also touch one lead to a ground wire and then the other lead to the other wires (one at a time). Testing Installed Outlets for Current: Take the circuit tester (make sure you NEVER touch the metal leads on the tester) and insert one lead in each opening (Fig. 1). The tester will glow red if current is present. One note about this test: It is possible to stick the circuit tester into a live outlet and get no indication of current (Fig. 2). When you use the circuit testers with the little red light (I think it is neon), make sure that you move it around a bit if you get no reading. Testing installed Outlets for Ground: If you need to test an installed outlet for ground, stick one lead into the right (short) slot and the other lead into the U shaped ground hole at the bottom (Fig. 3). If the light glows, the outlet is grounded. If the light does not glow, take the lead from the right slot and put it in the left slot. If the tester does not glow in either position, your outlet is not grounded. Testing Exposed Outlets for Current: Take one lead from the tester and put it on the ground wire. Touch the other lead to all connected wires (Fig. 4). If the tester glows, there is still power present. Testing Switches for Current: Put one lead on the ground wire and then touch the other lead to all of the other connected wires (Fig. 5). If, at any time, the tester glows, there is current on the switch. Testing Light Sockets for Current: Remove the light bulb. Place one lead against the conductor at the bottom of the light socket and one lead against the threaded sides of the socket (Fig. 6). If the light glows, there is current.

Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6