Absence of Voltage Tester (AVT)

An Absence of Voltage Tester (AVT) is a permanently-mounted test device designed to verify that a circuit is de-energized prior to opening an electrical enclosure containing electrical conductors and circuit parts.


Prior to performing de-energized work on electrical equipment, NFPA 70E requires that workers verify equipment is in an electrically safe working condition. Until proven otherwise, equipment must be treated as energized and necessary precautions must be observed. One of the steps in the process of verifying that equipment is in an electrically safe state involves a test for the absence of voltage. An Absence of Voltage Tester (AVT) is a permanently-installed device on an electrical enclosure that automates and simplifies the process of absence of voltage verification testing. 

VeriSafe™ Absence of Voltage Tester by Panduit

When servicing electrical equipment, workers must comply with safety regulations that require a voltage verification test to validate the absence of voltage. This process includes a number of stages that can be complex and time-consuming when using hand-held portable test instruments. The patent-pending VeriSafe™ Absence of Voltage Tester (AVT) from Panduit simplifies this process by automating the voltage verification process. Once installed, a push of a button enables qualified electrical workers to verify the absence of voltage and see an active indication when the absence of voltage is confirmed (figure 1). 

Figure 1. An electrical worker using VeriSafe™ AVT (Photo courtesy of Panduit)

Substituting Traditional Portable Testers

Before and after testing, the functionality of the tester must be verified on a known source. When using a portable tester, this may involve exposure to electrical hazards. While these portable testers may warn of hazardous voltage, it cannot be used to confirm if equipment is de-energized. 

The VeriSafe™ AVT follows a Prevention-through-Design (PtD) concept that substitutes the use of portable testers. With a permanently-mounted device satisfying the requirements described in NFPA 70E-2021 120.5 (7) Exception 1 and installed in accordance per the manufacturer's instructions, this reduces risk to electrical hazard exposure and ensures the test process is performed in the proper sequence (figured 2). 

Figure 2. A comparison of testing methods between a portable tester and VeriSafe™ Absence of Voltage Tester. (Photo courtesy of Panduit)

VeriSafe™ AVT Use Guide

There are various indicator lights illuminated to the user. When properly installed, an illuminated red light indicates hazardous voltage is present. Though, the absence of any light on the device does not guarantee the absence of voltage. A user will then press the test button to begin the testing sequence indicated by a flashing yellow light. During this step, the device will perform the sequential process of: 1) testing the device itself, 2) verifying the installation, 3) checking for voltage, 4) verifying the installation, and 5) retesting the device itself. Once the test sequence is completed, only an illuminated green light will indicate the absence of voltage has been verified. 

For more information regarding the test sequence and product installation, please visit the manufacturer website.

Risks Addressed:

Death or serious injury can result if a worker is unexpectedly exposed to energized equipment.

How Risks are Reduced:

By substituting the use of portable testers with permanently-mounted AVT devices, an AVT can reduce the risk of exposure of electrical hazards for improved worker safety. It also supports compliance when used as part of the Lockout/Tagout process described in NFPA 70E and verifies electrical equipment is in an electrically safe working condition. 

Electrical hazard exposure is reduced for qualified electrical workers via guarding since the voltage testing equipment is installed outside of electrical enclosures and away from the shock and arc flash boundaries. Using permanently installed voltage testing equipment when verifying the absence of voltage eliminates the need to place testing leads on live parts.

Effects on Productivity:

The use of permanently installed voltage testers reduces the workers exposure to the electrical hazards via barriers. This allows qualified electrical workers to work more efficiently which increases quality, safety and productivity throughout the entire life cycle of the electrical equipment.

Additional Considerations:

As is the case with any construction tool and equipment, users should follow manufacturer safety recommendations and comply with any applicable local, state or federal regulations.


Jean Christophe Le, MPH - CPWR The Center for Construction Research and Training
Jerry Rivera - Washington, DC NECA chapter

Hazards Addressed: