Voltage Detection & Safe Isolation

About Voltage Detection & Safe Isolation

Detecting the presence of live voltage on AC circuits, switches, and outlets before working on them can be achieved with the use of a voltage detector.

Also known as voltage wands, sticks, "power sniffers" or pens, they clip into a shirt pocket and beep or glow when they detect voltage on exposed conducting parts or through insulation.

Voltage detectors can be used to detect live electricity anywhere, at levels between the stated voltage capabilities. They are used to check when power is off in electric switch boxes and other wiring before beginning a project.

A proving unit is a battery-powered portable device that serves as an electronic voltage source to safely verify the operation of electrical test tools such as digital multimeters (DMM), clamp meters, or other electrical testers.

Proving units evaluate that the internal components of the voltage tester are working correctly and that measurement accuracy is maintained. They come in many different forms to accommodate the vast voltage range spectrum that can be applied to two-pole testers.

Safe isolation refers to the process of disconnecting an electrical installation from the rest of the circuit and testing that no current is flowing through it. The purpose of isolating an installation is to ensure the safety of the people who are working on it, preventing them from receiving an electric shock.

All of the equipment you need can be purchased in the form of selected Safe Isolation Kits.

We offer a wide range of voltage detectors, proving units, and safe isolation kits from manufacturers such as Fluke, Megger, Lockout Lock, FLIR, TPI, and many more. Please browse through our selections and get in touch if you have any questions.

Popular Products

Fluke T5-600 Voltage, Continuity & Current Tester: Measures AC and DC voltages up to 600V and currents up to 100A without breaking the circuit, thanks to its open jaw design. It includes a continuity tester with an audible beeper for easy identification and features auto-ranging for simplified use. Built for durability, it's ideal for various electrical testing tasks.
Martindale NC4 Dual-sensitivity Non-contact Voltage Tester: A reliable tool for detecting AC voltage without direct contact. It offers dual sensitivity settings for both low and high voltage ranges, with clear visual and audible alerts for safety. Its compact, pen-like design is easy to use in tight spaces, and its durable construction withstands regular use in demanding environments.
Testo 750-1 Voltage Tester: Designed for testing electrical circuits, it can measure voltages from 12 to 690V AC/DC, providing clear LED step increments for easy reading. This tester also features low input impedance, phase sequence testing, and continuity testing capabilities. Its all-around LED display ensures visibility from any angle, and the ergonomic handle with an anti-slip ring enhances user comfort and safety.
Seaward PH3 Proving Unit: Compact, battery-powered device for verifying high voltage indicators, live line testers, and digital potential indicators. It generates a DC output voltage of 1200V to 1500V, allowing users to confirm the operation of voltage indicators before and after use. Its domed contact electrode and robust, portable design make it a reliable choice in the field.
Martindale PD690S 690V Proving Unit: Verify voltage indicators and test lamps up to 690V. It features a rugged, over-moulded design and a high-strength magnetic hanger for ease of use. Essential for safe isolation procedures, it ensures your equipment is working correctly before and after use. With long battery life and a low battery indicator. The instrument is available with a case.
Fluke PRV240 Proving Unit: Compact, battery-powered voltage source for verifying electrical test tools. It provides stable AC and DC voltages for both low and high-impedance instruments, ensuring correct operation before and after live tests. Enhancing safety by reducing shock and arc flash risks, it features a single LED indicator for easy functionality checks and a magnetic hanging strap for convenience. With a long battery life, it can perform up to 5,000 tests per set of four AA batteries.
Socket & See Range with optional Lock Packs: The kits contain a voltage tester, proving unit, safe case, and an optional lock pack. VIP150 & VIP200 Voltage Testers and SP200 & SP400 Provig Units are available in the range.

FAQs

What is safe isolation?
Safe isolation is essential for ensuring electrical circuits and equipment are fully de-energized before maintenance or repairs. The procedure involves identifying and switching off the circuit, locking it to prevent accidental re-energization, and verifying de-energization with a voltage tester and proving unit. These steps help protect workers from electrical hazards and maintain a safe working environment.
Why is safe isolation important?
Safe isolation is crucial for ensuring that electrical circuits and equipment are fully de-energized before work begins. This prevents accidental shocks, arc flashes, and other electrical hazards, thereby protecting workers from serious injuries or fatalities. Adhering to safe isolation procedures helps maintain a safer work environment and ensures compliance with safety regulations.
What equipment is required for safe isolation?
For safe isolation, several key pieces of equipment are essential. A voltage detector is used to verify the presence of voltage, while a proving unit confirms the detector’s accuracy. Lockout devices, such as grip-tight MCB lockouts and mini circuit breaker lockouts, are crucial for securing the circuit. A safety padlock and key lock these devices in place, and lockout tags are used for identification and warnings.

Additionally, a steel lockout hasp is useful for allowing multiple workers to lock out a single energy source. These tools ensure that electrical circuits are properly de-energized and secured, preventing accidental re-energization and maintaining a safe working environment.
How can I ensure the safe isolation of electrical circuits?
To safely isolate an electrical circuit, identify and switch off the isolation point, secure it with lockout devices, verify the circuit is de-energized using a voltage indicator, apply safety earth if necessary, place danger notices, and issue a permit to work if required. This ensures the circuit remains safe and prevents accidental re-energization.
Why do I need a proving unit?
A proving unit is crucial for confirming that your voltage indicator or test lamp is operating correctly both before and after testing an electrical circuit. This ensures the reliability of the device and verifies that the circuit is genuinely de-energized, which helps prevent false readings and enhances safety. Essentially, the proving unit acts as a safeguard to ensure your testing equipment is functioning properly, thereby reducing the risk of electrical accidents.
Can I use a multimeter instead of a proving unit?
A multimeter can measure voltage and check if a circuit is live, but it doesn't replace a proving unit. A proving unit specifically tests your voltage indicator or test lamp, ensuring their accuracy before and after circuit testing. This step is essential for confirming the reliability of your testing equipment and enhancing safety by reducing the risk of false readings and confirming that the circuit is de-energized.
How often should proving units be used?
Proving units should be used each time you test an electrical circuit. Always check your voltage indicator or test lamp with the proving unit before and after circuit testing. This practice ensures your equipment is working properly and provides reliable readings, thereby enhancing safety.
What are the safety features of proving units?
Proving units enhance safety by delivering a known high voltage output to test voltage indicators and lamps. They feature self-test functionality, durable construction, clear visual or audible signals, and battery status indicators to ensure reliable operation.
What is the correct equipment to use for proving dead?
To confirm a circuit is dead, use both a dedicated voltage indicator and a proving unit. The voltage indicator detects voltage, while the proving unit ensures the indicator’s accuracy before and after testing. This approach guarantees reliable and safe operation, with equipment adhering to standards like BS EN61243.
How does a voltage detector work?
A voltage detector, or non-contact voltage tester, detects the electric field generated by alternating current (AC) in a wire or outlet. When brought near a live wire, the detector senses this field and converts it into a visual or audible signal, indicating voltage presence. This method, known as capacitive coupling, enables voltage detection without direct contact with electrical components.
What are the key features to look for in a voltage detector?
When selecting a voltage detector, opt for one with non-contact detection, a broad voltage range, clear visual and audible indicators, durable construction, a battery status indicator, ergonomic design, and self-test functionality. These features ensure reliability, safety, and ease of use.
What safety precautions should I take when using a voltage detector?
When using a voltage detector, consult the manual, check the device for damage, test it on a known live source before and after use, wear protective gear, avoid wet conditions, and keep your hands and body away from live parts during testing to ensure safety and reliability.
Can a voltage detector be used on all types of electrical systems?
Voltage detectors are mainly designed for AC systems and are best for identifying live wires in standard household and commercial setups. However, they might not be suitable for all electrical systems, such as high-frequency circuits, shielded cables, or DC systems, depending on the model. Always consult the manufacturer’s specifications to confirm that the voltage detector is suitable for your specific application.
Why can't I use a multimeter or non-contact voltage detector to prove dead?
Using a multimeter or non-contact voltage detector to confirm a circuit is dead is not recommended, as they may not reliably confirm the absence of voltage. Multimeters can provide false readings if not used properly, and non-contact detectors may be influenced by factors like electromagnetic interference. For accurate and reliable confirmation that a circuit is de-energized, use a dedicated voltage indicator verified with a proving unit to ensure enhanced safety.
How do I choose the right voltage detector for my needs?
To select the right voltage detector, ensure it offers accurate readings, covers the necessary voltage range, is user-friendly and durable, and has clear visual and audible indicators. Additional features such as self-testing capabilities or a flashlight can enhance functionality.