How to Use a Voltage Tester

If you are using a new voltage tester, it is recommended to confirm the device is working correctly to avoid any false readings when using it. No-contact voltage testers usually display a green LED light continuously when the device is on. Check and confirm that the LED light on your voltage tester is glowing.

Next, switch on any tube light in your room. Place the tip or probe, of the tester on the glass surface of this light. The LED light of the voltage tester should now glow red. The tester will also produce a rapid beeping sound. This means your device has detected the voltage and is working correctly.

It is possible that your device's green LED light is not turning on. This often happens when the batteries are low. Find the battery cap at the rear of the no-contact voltage tester. Unscrew this cap and open it. Take out the old batteries. Take the new batteries and put them inside.

Make sure the batteries are positioned in the correct order of polarity. The plus sign on the battery must be placed next to the left sign on the voltage tester. Take reference of the plus and minus sign markings on the batteries and the voltage tester.

Access the electrical component you want to test.

• To check an electrical outlet, touch the probe to one of the slots on the receptacle. Place it on the other slots to check them one by one. 
• If you are testing a breaker switch, touch the probe to the switch panel inside the box. 
• You can also test a light switch with the help of a no-contact tester. First, turn on the switch. Unscrew the faceplate with a screwdriver and remove it. Now, simply touch the probe of the tester to the screw terminals. You can find these screw terminals on the side of the switch.
• When checking a light fixture, turn off the switch and unscrew the light. This will expose the light socket. Touch the probe of the tester inside this socket.

As soon as you touch the probe, the LED light on the tester might glow red. It may also start producing a rapid beeping sound. This will indicate the presence of a voltage in the electrical component. If you do not notice a red LED glow or any beeping sound, it is likely due to the absence of any voltage.

Press the power button on the voltage tester for a few seconds. It will beep twice, and the LED lights will stop glowing. This will indicate that the voltage tester is now turned off.