How To Select Electrical Testers

Whenever you’re working with electricity, it’s important to have an electrical tester on hand to make sure you’re not touching any live wires. However, not all electrical testers are the same. Depending on your needs, you may need one or even a few electrical testers in your home. 

In the video above, Ask This Old House lighting expert Scott Caron showcases several electrical testing tools and their uses. In this guide, we’ll break down the different types of electrical testers and how to choose one that’s right for you.

Types of Electrical Testers

Electrical testers come in various forms, each designed for specific tasks. Understanding the different types can help you choose the right tool for the job.

Non-Contact Voltage Tester

Non-contact voltage testers, also known as voltage pens or pen testers, are handheld devices that detect the presence of electrical current without needing direct contact with wires. Here are the main characteristics of these testers:

• Are easy to use and portable
• Are ideal for quick checks before opening electrical boxes
• Can detect voltage through wire insulation
• Typically come with visual and audible alerts

These testers don’t provide specific voltage readings or detailed diagnostics, but they’re perfect for initial safety checks. Simply hold the tester near a wire or outlet to determine if it’s live.

Receptacle Tester

Receptacle testers are designed to check the wiring of electrical outlets quickly. These testers have the following features:

• Can detect common wiring issues like reversed polarity or missing ground
• Often include a reference chart for interpreting results
• Plug directly into outlets for instant results
• Use light patterns to indicate the wiring status

These testers are extremely simple to use and provide invaluable help for homeowners and professionals alike. They provide a quick way to verify that outlets are correctly wired and safe to use.

Digital Circuit Breaker Finder

A digital circuit breaker finder consists of two parts: a transmitter and a receiver. This tool helps identify which circuit breaker controls a specific outlet or fixture. A digital circuit breaker finder works by doing the following:

• The transmitter plugs into an outlet or connects to a fixture.
• The receiver scans the electrical panel to locate the corresponding breaker.

This tool is particularly helpful in homes with outdated or poorly labeled electrical panels. Instead of using trial and error to figure out which breaker is which, this tool makes it easy.

Voltage Tester

Voltage testers, also known as multimeters, are versatile tools that can measure voltage, current, and resistance. These testers have the following characteristics:

• Are available in analog and digital models
• Can measure AC and DC voltage
• Include probes for direct contact with electrical components
• Often include additional features like continuity testing

Voltage testers are essential for diagnosing complex electrical issues and are a staple in any electrician’s toolkit.

Continuity Tester

Continuity testers are specialized tools used to determine if a circuit is complete. They are particularly handy when diagnosing issues with wiring. These testers do the following:

• Use light or sound indicators for simple diagnostics
• Help in identifying broken wires or poor connections

These testers work by sending a small current through the circuit. If the circuit is complete, the tester signals with a sound or light. They’re especially handy when testing wiring for lights or automotive projects.

How To Choose an Electrical Tester

Most homeowners only need testers for basic electrical troubleshooting and safety checks. Non-contact voltage testers and receptacle testers are enough for most DIY projects. These tools are easy to use and provide quick results, making them ideal for minor home repairs and electrical tasks.

Professional electricians, on the other hand, may need more advanced tools. They’ll likely use all the electrical testers listed above and additional multi-functional testers to handle different types of jobs.

Using Electrical Testers Safely

Safety should always be the top priority when working with electricity. Here are some tips for using electrical testers:

1. Read the manufacturer’s instructions thoroughly before use.
2. Test the tester on a known live circuit before each use to ensure it’s functioning correctly.
3. Never rely solely on a non-contact voltage tester to confirm the absence of voltage.
4. Keep testers clean and dry, and store them in a safe place when not in use.
5. Always choose tools rated for the voltage levels you’ll be working with.

Remember, even with the best tools, electrical work can still be dangerous. If you’re unsure about performing electrical work, it’s always safer to consult a licensed electrician. For more safety tips, check out the Occupational Safety and Health Administration’s electrical safety guide.

Proper Testing Procedures

Before beginning any electrical project, establish safe testing routines. Start by turning off the circuit breaker or removing the fuse that corresponds to the area you’re working on. Double-check for live wires using a voltage tester, preferably one that can measure both AC and DC currents.

Always hold testers by their insulated handles and avoid touching any exposed metal parts. When testing outlets, insert the probes gently and verify the readings on both sides. For more complex diagnostics, ensure you’re familiar with all the functions of your multimeter, including its settings and calibration methods.

Calibration and Upkeep

Calibration is critical for maintaining the accuracy of your electrical testers. Follow the manufacturer’s guidelines and schedule regular calibration checks. Many modern multimeters and advanced testers include built-in calibration functions, making this process easier. Replace worn-out leads and connectors promptly to avoid inaccurate readings or mishaps during testing.

For contact-based testers like multimeters and continuity testers, keep the probes clean. Wipe them down with isopropyl alcohol after each use to remove any residue that might affect performance.

Common Electrical Issues Detected by Testers

Electrical testers can help identify a variety of common household electrical problems. Identifying these issues early can prevent more serious electrical problems and potential safety hazards in your home.

Diagnosing Faulty Wiring

Faulty wiring is a common issue in older homes and can lead to various problems, including flickering lights and malfunctioning outlets. Use a receptacle tester to check for wiring issues such as reversed polarity and missing grounds. For a more detailed analysis, a multimeter can measure voltage drops and identify specific sections of wiring that may need replacement.

Test your GFCI outlets regularly to ensure they function correctly. Faulty GFCI outlets can pose significant shock hazards. Receptacle testers typically include GFCI testing capabilities, making it easy to verify the safety of these critical components.

Circuit Identification

In homes with complex or unlabeled electrical panels, identifying the correct circuit breaker can be challenging. A digital circuit breaker finder is invaluable in these situations. By efficiently mapping out your electrical circuits, you can label and organize your panel to make future electrical work more straightforward and safer.