Permanently installed absence of voltage testers

Listen to this article

Eliminating electrical hazards must be the first priority in staying safe when working on electrical equipment. Establishing an electrically safe working condition must be a common practice with you and your employer. Consider performing all eight steps of 120.6 of NFPA 70E to stay safe!

Using a permanently installed absence of voltage tester can be used to test for the absence of voltage. This device will avoid selecting a proper portable tester and wearing arc rated PPE while breaking the restricted approach boundary when doing Step 7 of 70E:120.6.

There is a 50/50 chance of two results from any electric shock. There is a 50% chance of pain and discomfort. Or a 50% chance of death! The odds are not in your favor. The hazards from just a slight electric shock are still being studied and not fully understood by those in the medical profession. Long-lasting neurological, physical and psychological complications are being reported, recognized and studied.

This column is about how to help eliminate shock as well as an arc flash event. Understanding and implementing NFPA 70E may seem like an overwhelming task for most people. However, there are eight simple steps we all can at least consider performing, that will help eliminate the hazards and keep you and your people safe no matter what size company. It does not matter the type of work, type of occupancy, or how you feel about de-energized work and complying with NFPA 70E. Compliance is for everyone, everywhere.

First, look at the documentation. In section 130.2(A) and (C), of NFPA 70E you can see requirements for an EEWP (Energized Electrical Work Permit) when work is done within the restricted approach boundary and is not exempted in the exceptions. For Phase-to-Phase voltages of 750 volts or less, the restricted approach boundary is 12 inches measured outward in all directions from the exposed energized parts. One of the exceptions is testing, troubleshooting, or voltage measuring.  In all cases proper PPE must be worn while doing this process or while you are within the limited approach boundary of 3 feet, 6 inches. The Category of PPE is selected from information found on the Arc Flash label or the task table found in NFPA 70E, 130.7(C)(15)(a) for ac systems and Table (b) for dc. If the voltage is 50 volts or more and if you are not testing or troubleshooting, you must get an energized work permit to do the task. This permit is not from the city, or county, or the AHJ. We generate it and it must be signed off by many various stakeholders including owners, supervisors, safety personnel, and even the crew doing the work. The EEWP is basically the last door to shut before the point of no return. Before commencing work on the exposed energized electrical parts everyone must sign off and agree that this is the only option, and additional hazards will exist if power is interrupted.  When signatures are required, it typically will force people to reevaluate the task and look for ways to schedule an outage with the timeframe and costs of the outage to be predictable and fixed. Or the other option is risking an unscheduled outage with the costs and timeframe to exceed all expectations. There may be cases where the replacement of equipment that could be damaged during an arc flash event, may not be available locally, require endless lead-times, or even just be obsolete equipment. This information should be included in the EEWP. To avoid all of this, just put the system into an (ESWC) Electrically Safe Working Condition. In NFPA 70E, Article 120, Section 6, you will find the eight-step process to do this. Performing this process itself does not bring you in compliance with 70E but it may help in saving a life or risking injury. An ESWC is not as simple as just turning the power off and testing for the absence of voltage. All eight steps must be considered and if necessary implemented if applicable. The fifth and eighth step might not be applicable, but it should at least be considered.

Step 1: Check up-to-date drawings diagrams and identification labels and tags to help accurately locate the upstream source for disconnection. Using Arc Flash labels in compliance with 110.16 of the NEC as a source of information can also help. In the 2023 NEC services and feeders of 1000 amperes or more to have arc flash labels affixed to the equipment. The new 2026 NEC requires arc flash labels on both service and feeders. No restrictions for voltage or current.

Step 2: After opening the downstream loads to minimize any arcing while opening the upstream device, open the disconnecting means for each power source. Some systems may have more than one source. Be mindful of alternative energies and their supplies. Solar power. Generators. Batteries

Step 3: If possible, visually verify the blades of the disconnecting means are open. If it is a draw-out type breaker, make sure it is, in fact, drawn out.

Step 4: Release stored energy. This would include inductive or capacitive electrical energy. Energy storage systems and solar would need to be disconnected.

Step 5: Block or relieve stored nonelectrical energies. This could be hydraulic, pneumatic, or kinetic energy that also serves the equipment that you intend to work on. This could apply to machines or other mechanical equipment or processes.

Step 6: Apply LOTO (Lock-out, Tag-Out). Do this in accordance with the policies and procedures established by your company and/or the host contractor or the client that your employer was hired to work for.

Step 7: While using the correct portable testing equipment, verify the absence of voltage. Make sure the tester is rated for the voltage that you are testing. Test your tester first. This is commonly called a LIVE-DEAD-LIVE test. Then test each phase as well as each phase to ground. Test the tester again after verifying absence of voltage. Tip: Do not hold the tester in your hands if you can avoid it. Do not rely on noncontact, induction type, testers for this process. At least not for systems under 1000 volts. This type of tester only works on AC (alternating current) and cannot read voltage on conductors with metallic jackets or shielding.  New, permanently installed, absence of voltage testers are permitted in the exceptions to this step. This would include VeriSafe® from Panduit or the ChekVolt™ from Grace Technologies. Some company policies include verifying with a portable tester before touching the electrical parts after initiating one of these devices.  It is at this step where most accidents happen so make sure you are qualified to select and use the testing equipment safely. Using a device that is permanently installed is faster and safer than using a portable tester. It removes the human interaction with the hazard. Voltage rated gloves are required whenever your hands or what you’re holding enters the restricted approach boundary. See 130.7(C)(7)

Step 8: And finally, if there is the possibility of an induced voltage by induction or if capacitive charges are present, apply temporary protective grounding equipment. If properly installed and sized correctly this will also cause the immediate opening of the protective device if the circuit is unintentionally re-energized. Just one more level of safety. This is a temporary bolted-fault condition which also eliminates induced or stored energy on the conductors or circuit parts. It’s not always required but if feasible, apply the ground clusters.

In closing, you can apply all, or most, of these steps while working on energized electrical equipment. I would suggest starting a new mantra, “If the plumbers shut off their systems, why don’t we?” Why don’t you? Almost every time I worked on my client’s electrical problem the question was asked of me. “Are you going to shut of my power?” They expect us to turn off the power and be safe. NFPA 70E requires us to “eliminate” the hazard in section 110.1. So why do we think it is not important? Or maybe, there is still this sense of pride while doing it dangerously. How much pride does it take to recover from an electric shock or serious burns as a result of an arc flash?