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How to Use a Non-Contact Voltage Tester: The Ultimate Guide 2024

If you're looking for an easy way to detect live voltage without making contact, a non-contact voltage tester is a tool for you! In this guide, I'll teach you how to use a non-contact voltage tester safely and effectively. I'll also provide some tips on choosing the right tester for your needs. 

In 2024, mastering the use of a non-contact voltage tester is essential for electrical safety. This comprehensive guide provides step-by-step instructions for efficient and accurate testing procedures.

So whether you're a professional electrician or just someone who likes to do DIY projects around the house, read on for everything you need to know about using a Non-Contact Voltage Tester!

What is a Voltage Tester? 

A voltage tester is a device used to detect the presence of electricity. It's also known as a voltmeter or multimeter. Voltage testers are used to test electrical circuits, outlets, and wiring for live voltage. They're an important tool for electricians, as they help ensure that electrical systems are safe to work on.

Voltage testers are essential tools for electricians and DIY enthusiasts alike, enabling the detection of electrical voltage without direct contact. This comprehensive guide delves into the various types of voltage testers available in the market, each offering unique features and functionalities tailored to specific needs.

1. Non-Contact Voltage Testers:

Non-contact voltage testers, also known as voltage detectors, utilize electromagnetic field detection to identify the presence of voltage without physical contact with the electrical conductor. They typically feature a handheld design with an indicator light or sound alarm, making them suitable for quick and safe voltage detection in various applications.

2. Contact Voltage Testers:

Contact voltage testers, also referred to as test pens or voltage probes, require physical contact with the electrical conductor to detect voltage. These testers feature a metal probe that is inserted into the electrical outlet or wire terminal to measure voltage levels. They often come with additional features such as digital displays or audible alarms for precise voltage readings.

3. Two-Pole Voltage Testers:

Two-pole voltage testers, also known as voltage testers with integrated load, are versatile tools capable of performing both voltage detection and continuity testing. They feature two probes that are placed on the circuit to measure voltage levels accurately. Some models also incorporate additional functionalities such as resistance measurement and phase sequence testing, making them ideal for comprehensive electrical testing tasks.

4. Solenoid Voltage Testers:

Solenoid voltage testers, also called neon testers or solenoid testers, employ a solenoid coil mechanism to detect voltage. When the tester detects voltage, the solenoid coil energizes, causing a neon bulb to illuminate or an audible buzzer to sound. These testers are simple in design and are often used for basic voltage detection tasks in residential and commercial settings.

Contact Voltage Testers Vs Non-Contact Voltage Testers

There are two main types of voltage testers: contact and non-contact. Contact voltage testers require that you make physical contact with the circuit in order to test it, while non-contact voltage testers can detect electricity without making contact. Non-contact voltage testers are often preferred, as they're safer to use and less likely to damage the circuit.

When should you use a non-contact voltage tester?

Non-contact voltage testers are most commonly used to test for live voltage in electrical circuits, outlets, and wiring. They can also be used to test for loose connections, damaged insulation, and other electrical problems.

If your electrical circuit is live then it becomes difficult to test without coming in contact with the circuit. This is where a non-contact voltage tester comes into play as it helps you to test for live voltage without disconnecting the circuit or opening wires.

Most of the time light switch stops working but you don't know the causes. Therefore, an NCV multimeter helps you in identifying the problem without getting in touch with electricity directly.

How does a non-contact voltage tester work?

A non-contact voltage tester uses an infrared sensor to detect the presence of electricity. The tester will emit a beeping sound and the LED light will turn on when it detects the live voltage. NCV multimeter or Non-contact voltage detector detects only hot wire so use it only on live wires.

Most of the non-contact voltage testers have two sensors, one for detecting AC voltage and one for DC voltage. The tester will usually have a switch to toggle between the two.

How to use a non-contact voltage tester- Step by Step Guide

Now that you know the basics of using a non-contact voltage tester, let's go over how to use one step-by-step. Using a non-contact voltage tester is simple and only requires a few steps:

  • First, make sure that the area you'll be testing is dry and free of debris.
  • Next, turn on the tester by pressing the power button.
  • Then, hold the tester close to the circuit, outlet, or wiring you wish to test.
  • If the tester detects live voltage, it will emit a beeping sound and the LED light will turn on.
  • If the tester does not detect any voltage, the beeping sound will stop and the LED light will turn off.
  • Most of the Non-contact voltage testers have range settings so that you can test for different voltage levels. If your tester has this feature, be sure to set it to the correct range before testing.

What are the major benefits of using a non-contact voltage tester or voltage detector?

There are many benefits of using a non-contact voltage tester, but here are three of the most important:

1. Safety:

Non-contact voltage testers are much safer to use than contact testers. This is because you don't have to make physical contact with the circuit, which can be dangerous.

2. Easy to use:

Non-contact voltage testers are very easy to use. Simply turn it on and hold it close to the circuit you wish to test.

3. Affordable:

Non-contact voltage testers are very affordable, making them a great tool for electricians and DIYers alike.

They help to ensure that electrical systems are safe to work on, and can save you time and money in the long run. So, if you're looking for an easy and safe way to test for live voltage, a non-contact voltage tester is the way to go!

Best Non Contact Voltage testers for Electricians-Top 3 Picks

Now that you know how to use a non-contact voltage tester, let's take a look at three of the best testers on amazon.

1. Klein Tools NCVT-4IR Non-Contact Volt Tester

Electrical wiring and systems can be dangerous, and it's important to be able to accurately detect the voltage in order to avoid injury or damage. Klein Tools' NCVT-4IR Non-Contact Volt Tester is designed specifically for HVAC applications, making it the perfect tool for professionals who work with electrical wiring and systems.

This voltage tester provides non-contact determination of AC voltage in cables, cords, circuit breakers, switches, outlets, and wires, as well as AC voltage in security, entertainment, communications, environmental control, and irrigation systems.


  • It also detects AC voltage from 12 to 1000V with visual and audible indicators.
  • Plus, it has a convenient laser pointer to target the measurement area for temperature measurement.
  • The backlit LCD display can get an accurate reading every time.
  • Moreover, the auto-shutdown feature in case of inactivity helps to conserve and extend battery life.
  • This tester is also equipped with a low battery indicator so you never get caught off guard.

2. Fluke 1AC-A1-II VoltAlert Non-Contact Voltage Tester

You're working on a project and you think you might have hit a live wire. You don't want to take any chances so you reach for your voltage tester, but which one do you choose? The Fluke 1AC-A1-II VoltAlert Non-Contact Voltage Tester is the answer. Let's see some of its main features in detail.


  • The tester also features a bright red LED that flashes on and off to indicate the presence of AC voltage.
  • In addition, it has a low battery indicator so you can always tell when it's time to replace the batteries.
  • This voltage tester has CAT IV 1000 V safety protection.
  • It features Voltbeat technology with continuous self-test so that you always know it is working properly.
  • Plus, the 20-volt to 90-volt AC control circuit model is also available.
  • Finally, the tester comes with a user-replaceable long-life battery.

3. Sperry STK001 Non-Contact Voltage Tester

Accidentally shocking yourself while working on an electrical installation is a real risk. Not only could it cause serious injury, but it could also lead to costly damage. The Sperry STK001 Non-Contact Voltage Tester detects the presence of AC Voltage without coming into contact with any wires. This allows you to work safely and confidently.


  • With its non-contact design, it can easily detect AC voltages from 50 to 1000V, so you can be sure that it's safe to proceed.
  • Plus, the bright color-coded neon lights make it easy to see at a glance whether there's voltage present.
  • If you're ever unsure, the self-test feature will let you know if the tester is working properly.
  • It is a 10Ft drop test certified voltage tester.
  • CAT-III 1000V safety ratings allow you to detect voltages safely.

Tips & Tricks for using a non-contact voltage tester safely

As with any electrical tool, it's important to use a non-contact voltage tester safely. Here are some tips to help you stay safe while using one:


  • Always read the manual before use. This will help you understand how the tester works and how to use it properly.
  • Wear protective gear when using the tester. This includes gloves, safety glasses, and a face shield.
  • Never use the tester on wet circuits or in wet areas. This can be dangerous and damage the tester.
  • Be sure to set the range selector to the correct setting before testing. This will help ensure accuracy and prevent damage to the tester. The light bulb or Neon lights don't consume many amps and have small voltage. Therefore, it's important to set the ranges of NCV testers to the minimum level.
  • If the tester emits a continuous beeping sound or the LED light stays on, this means the circuit is live. Do not touch the circuit and contact an electrician immediately.
  • Never use the tester on too close to naked conductors circuits. This can be extremely dangerous and should only be done by a qualified electrician.


  • Sometimes the test cables in an electrical box or in a light fixture have rough electrical work so to avoid any injury it's better to avoid direct contact with the voltage source.
  • For high voltage measurements, you need a volt stick to avoid any electrical hazard. A lot of high voltage non-contact tester come with a volt stick. Therefore, you must use that.
  • A non-contact voltage detector can not work properly in capacitive coupling conditions. such conditions occur due to the flux of one cable on another so avoid testing close connected cables.

By following these tips, you can use your non-contact voltage tester safely and effectively.

Still, have questions about using a non-contact voltage tester? Leave a comment below and I'll be happy to help!