How to Check the Power on a Voltage Meter

Using a voltmeter to check the power on an electrical circuit is an accurate way for diagnosing problems. Although voltmeters may come in many different styles, they all operate the same way and have the same colored leads for checking power. By following a basic setup process, you can check power with a voltmeter in a matter of minutes.

Things You'll Need

• Voltmeter
• Leads for voltmeter
• Duplex outlet

Instructions

1. Plug in the two leads of the voltmeter into the sockets on the front face of the device. The red lead will go into the socket identified as "Voltage," and the black lead will go into the opening identified as "Common" or "Ground." In these steps, we will be testing the voltage on a common outlet in the home.

2. Switch the voltmeter on by turning the main control knob to "Volts AC." Some voltmeters may have multiple positions for the switch. For AC circuits, it is placed in the "Volts AC" position.

3. Observe the reading on the meter. An LED display will show "0.0" volts on the screen. An analog-type meter or a meter with a movable deflector needle will be in the far-left position at zero, "0."

4. Notice on the wall outlet that you should have three openings on the face of the plug-in terminal. The lower hole, which resembles a partial circle, is used for the safety earth ground. The smaller vertical slot above it and to the right is the "hot" or power feed side of the plug, and the slightly longer vertical slot to the left is the neutral side, or return path of the circuit.

5. Place the red lead tip of the meter into the "hot" or power feed side of the outlet and the black lead into the round earth ground hole. The meter should now register between 110 and 125 VAC, depending on the power company's voltage. If it is not, wiggle the red lead a little in the "hot" side of the outlet.

6. Remove the black lead from the earth ground hole and check the larger vertical slot of the neutral side of the outlet. The meter should have gone from 0 to the same reading as in Step 5.

7. Test other circuits in the same fashion. You must always have a continuous path for the electrical circuit to travel. In other words, the red lead should always be placed on the "hot" side or power feed of the circuit, and the black lead on the neutral return path or safety earth ground.

Tips & Warnings

• Follow all manufacturer's warnings and operation safety tips when using a voltmeter for checking power.