Page 18 - Occupational Health & Safety, April 2019

ELECTRICAL SAFETY
Listing Requirements Help Absence-of-Voltage Testers Become a Better Way to Prevent Workplace Injuries
AVTs improve worker safety by automating and simplifying the process of verifying the absence of voltage.
BY RACHEL BUGARIS The importance of creating a safe workplace can’t be understated. When it comes to elec- trical hazards, a comprehensive approach to risk control that includes not only policies and procedures, but also reducing exposure through design and use of the latest technology, is crucial. There’s a lot to account for, but there’s a lot at stake, and the rigorous monitoring of industry best practices can go a long way when it comes to providing workers the safe working environment they need and deserve.
Finding a Better Way to Verify
the Absence of Voltage
Performing work without turning off power and veri- fying that a de-energized condition exists is a leading cause of electrical injuries. A study1 on common prac- tices with voltage test instruments found that, during a five-year period, 18.3 percent of facilities surveyed had a personal injury occur when using handheld voltage-test instruments, and 11.7 percent of them experienced a plant operation interruption because of voltage testing incidents.
According to Electrical Safety Foundation Inter- national statistics,2 there were 2,210 nonfatal electrical injuries in 2017, an increase of 35 percent over 2016. Shocks accounted for 1,330 nonfatal electrical inju- ries, while burns accounted for 900. A study3 of the U.S. Occupational Safety and Health Administration (OSHA) injury database found that about 60 percent of incidents with key words “electric arc” and “burn” occurred at low voltages (<1,000 V), with the majority of these on three-phase systems. A common reaction to these data is to propose more safety training, but training alone is not sufficient. In a study4 of electri- cal burn patients, researchers found that none of the patients followed all appropriate safety measures. It has been estimated that finding a better way to verify the absence of voltage on low-voltage systems could lead to as much as a 20 percent reduction of electrical injuries in the workplace, which equates to 10 fewer injuries per week in the United States alone.
Looking at the hierarchy of controls, the most ef- fective measures to control risk include elimination, substitution, and the introduction of engineering controls to equipment, processes, and tools. Reduc- ing exposure to hazards via design choices should be the first choice whenever possible, rather than relying solely on administrative policies and procedures or
PPE. Absence-of-voltage testers (AVTs) are perma- nently mounted testing devices specifically designed with this in mind. Alternatively, an AVT determines whether a circuit part is de-energized prior to open- ing panels or removing covers to access and maintain electrical equipment. Panduit introduced the first absence-of-voltage tester, the VeriSafeTM AVT.
AVTs take a Prevention through Design approach to electrical safety and are an ideal option for per- sonnel tasked with verifying the absence of voltage, whether it be for performing electrical work, me- chanical maintenance or other tasks requiring LOTO, or cleaning equipment. Before the introduction of the AVT, verifying that equipment was de-energized tra- ditionally relied on a portable handheld voltage tester. This method placed electrical workers at risk for ex- posure to electrical hazards while performing the test and verifying that the tester was functional, whereas the AVT allows the same test to be performed before the equipment is accessed. At the same time, AVTs help reduce human error. AVTs use an automated process and single step activation, standardizing the process to avoid missteps in execution and sequence, and they are designed to be robust and fail-safe, with numerous reliability features. The AVT enables em- ployees to verify the absence of voltage in a fraction of the time compared to handheld portable test instru- ments, and employees can move from job to job and task to task with confidence in their own safety.
Requirements for AVTs were added to UL 1436, Standard for Outlet Circuit Testers, in September 2016. This standard includes a comprehensive set of performance, functional safety, and listing require- ments for AVTs. UL 1436 references construction requirements in UL 61010 (Parts -1 and -2-030), the same standards that contains listing requirements for digital multimeters. Therefore, AVTs are evaluated to the same electrical construction requirements as your handheld tester, plus meeting additional requirements for permanently mounted equipment.
User-Initiated Test
UL 1436 requires that the user initiate the test for ab- sence of voltage with an AVT. This is intended to help ensure that performing the step is a conscious effort and that the test occurs at the point of use, reducing the likelihood of errors due to mislabeled or look- alike equipment.
14 Occupational Health & Safety | APRIL 2019
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