Zero Energy Verification An Alternative Approach. Timothy Snow CESCP Electrical Safety Officer

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1 Zero Energy Verification An Alternative Approach Timothy Snow CESCP Electrical Safety Officer

2 Hierarchy of Risk Control Methods In Order from Safest to Least Safe Elimination Substitution Minimizes Human Error Engineering Controls Awareness Administrative Controls Personal Protective Equipment NREL 2

3 Establishing An Electrically Safe Work Condition NFPA 70E 2018 Article ) Determine all possible sources of electrical supply to the specific equipment. 2) After properly interrupting the load current, open the disconnecting device(s) for each source. 3) Wherever possible, visually verify that all blades of the disconnecting devices are fully open or that drawout-type circuit breakers are withdrawn to the fully disconnected position. 4) Release stored electrical energy. 5) Release or block stored mechanical energy. 6) Apply lockout/tagout devices in accordance with a documented and established procedure. Steps 1 through 6 are Administrative NREL 3

4 Establishing An Electrically Safe Work Condition Zero Energy Verification 7) Use an adequately rated portable test instrument to test each phase conductor or circuit part to verify it is deenergized. Test each phase conductor or circuit part both phase-to-phase and phase-to-ground. Before and after each test, determine that the test instrument is operating satisfactorily through verification on any known voltage source. Step 7 is Energized Work exposing the worker to potential shock and arc-flash hazards. NFPA 70E 2018 Article NREL 4

5 Establishing An Electrically Safe Work Condition 120.5(7) Zero Energy Verification Exception No. 1: An adequately rated permanently mounted test device shall be permitted to be used to verify the absence of voltage of the conductors or circuit parts at the work location, provided it meets the all following requirements: (1) It is permanently mounted and installed in accordance with the manufacturer s instructions and tests the conductors and circuit parts at the point of work; (2) It is listed and labeled for the purpose of verifying the absence of voltage; (3) It tests each phase conductor or circuit part both phase-to-phase and phase-to-ground; (4) The test device is verified as operating satisfactorily on any known voltage source before and after verifying the absence of voltage. **If Exception 1 is implemented the Zero Energy Verification is not Energized Work. Risk is Minimized Chance of Human Error is Minimized NFPA 70E 2018 Article NREL 5

6 PANDUIT VeriSafe Absence of Voltage Tester (AVT) Panduit Corporation The first commercially available device that meets the criteria for 120.5(7) Exception 1. NREL 6

7 VeriSafe Highlights Can be used with circuits up to 600 Volts AC or DC Works with: 120 VAC Single Phase Three Phase Absence of Voltage Threshold 3V Capacitors DC Rated Category III at 600V, Category IV at 300V NREL 7

8 Sample One-Line of a VeriSafe Installation NREL 8

9 Operation Above Energized Circuit Upper Right De-Energized Circuit Lower Right Successfully Completed Absence of Energy NREL 9

10 Installation Example Installation using Piercing Taps on 600 MCM 480V-3PH-800A Incident Energy 3.3 Cal/cm 2 NREL 10

11 Cleanroom Installation Installation in NREL s Clean Room 480V-3PH-50A No Arc Flash NREL 11

12 Installation Using Crimp-Style Connectors 208V 110A Incident Energy 3.1 Cal/cm 2 NREL 12

13 Questions? NREL 13

Thank you www.nrel.gov This work was authored by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No.

14 Thank you This work was authored by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO Funding provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes.

15 NREL 15

Electrical Safety and Overcurrent Protection

Electrical Safety and Overcurrent Protection Dave Vallier DSE Bussmann division Contact info: Phone: 586-201-1348 Email: Davemvallier@eaton.com Agenda 1. Electrical hazards overview 2. The role of the