How has NFPA 70E 2024 changed voltage verification for electrical safety?
Overview
The electrical isolation of workspaces is crucial for preventing electric shock and hazards, thereby creating safe working conditions. NFPA 70E Section 120.6 outlines seven steps for establishing an electrically safe work condition, including identifying sources, opening disconnects, removing stored electrical and non-electrical energies from equipment, applying lockout and tag-outs as necessary, and verifying the absence of voltage. However, earlier versions lacked specificity regarding voltage verification locations, creating the risk of workers being shocked by hidden voltages. The 2024 version now mandates verifying the absence of voltage around the specific work area, thus enhancing end-user safety when dealing with electrical circuits.
Applying the 2024 Code
Electrically isolating the workspace is a fundamental safety measure to prevent electric shock and other electrical hazards. This procedure involves physically disconnecting the equipment from its power source and fully isolating it from any potential electrical energy. This isolation process establishes a safe working environment for personnel to conduct maintenance, repairs, or inspections without the risk of exposure to electrical hazards.
NFPA 70E Section 120.5 outlined the eight critical steps for establishing and confirming an electrically safe work condition. These steps include identifying all potential sources of electrical supply, opening disconnecting devices, visually verifying all blades are fully open, releasing stored electrical energy, blocking or relieving stored non-electrical energy, applying lockout/tagout devices, and verifying the absence of voltage on each phase conductor or circuit part of the equipment using a portable voltage measurement device. However, the specific locations for verifying the absence of voltage were not specified. Consequently, many workers took voltage readings in relatively accessible spots on the equipment circuits, which did not always reveal hidden voltages within the internal circuitry. This created the risk of workers being shocked by stray voltages in the work circuits. The 2024 version of NFPA 70E , now requiring the absence of voltage to be verified on and around the specific part of the circuit where the work is to be performed. This requirement aims to enhance end-user safety when interacting with electrical circuits.
What’s New for the 2024 NFPA 70E?
The table below presents a comparison between the 2021 NFPA 70E and the 2024 NFPA 70E regarding Section 120.6.
2021 NFPA 70E |
2024 NFPA 70E |
| 120.5 Process for Establishing and Verifying an Electrically Safe Work Condition
Establishing and verifying an electrically safe work condition shall include all of the following steps, which shall be performed in the order presented, if feasible: (1) Determine all possible sources of electrical supply to the specific equipment. Check applicable up-to-date drawings, diagrams, and identification tags. (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 draw out-type circuit breakers are withdrawn to the test or fully disconnected position. (4) Release stored electrical energy. (5) Block or relieve stored nonelectrical energy in devices to the extent the circuit parts cannot be unintentionally energized by such devices. (6) Apply lockout/tagout devices in accordance with a documented and established procedure. (7) Use an adequately rated portable test instrument to test each phase conductor or circuit part to test for the absence of voltage. 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. (8) Where the possibility of induced voltages or stored electrical energy exists, ground all circuit conductors and circuit parts before touching them. Where it could be reasonably anticipated that the conductors or circuit parts being de-energized could contact other exposed energized conductors or circuit parts, apply temporary protective grounding equipment in accordance with the following: a. Placement. Temporary protective grounding equipment shall be placed at such locations and arranged in such a manner as to prevent each employee from being exposed to a shock hazard (i.e., hazardous differences in electrical potential). The location, sizing, and application of temporary protective grounding equipment shall be identified as part of the employer’s job planning. b. Capacity. Temporary protective grounding equipment shall be capable of conducting the maximum fault current that could flow at the point of grounding for the time necessary to clear the fault. c. Impedance. Temporary protective grounding equipment and connections shall have an impedance low enough to cause immediate operation of protective devices in case of unintentional energizing of the electric conductors or circuit parts.
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120.6 Process for Establishing and Verifying an Electrically Safe Work Condition
Establishing and verifying an electrically safe work condition shall include all of the following steps, which shall be performed in the order presented, if feasible: (1) Determine all possible sources of electrical supply to the specific equipment. Check applicable up-to-date drawings, diagrams, and identification tags. (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 draw out-type circuit breakers are withdrawn to the test or fully disconnected position. (4) Release stored electrical energy. (5) Block or relieve stored nonelectrical energy in devices to the extent the circuit parts cannot be unintentionally energized by such devices. (6) Apply lockout/tagout devices in accordance with a documented and established procedure. (7) Use an adequately rated portable test instrument to test each phase conductor or circuit part at each point of work to test for the absence of voltage. 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. (8) Where the possibility of induced voltages or stored electrical energy exists, ground all circuit conductors and circuit parts before touching them. Where it could be reasonably anticipated that the conductors or circuit parts being de-energized could contact other exposed energized conductors or circuit parts, apply temporary protective grounding equipment in accordance with the following: a. Placement. Temporary protective grounding equipment shall be placed at such locations and arranged in such a manner as to prevent each employee from being exposed to a shock hazard (i.e., hazardous differences in electrical potential). The location, sizing, and application of temporary protective grounding equipment shall be identified as part of the employer’s job planning. b. Capacity. Temporary protective grounding equipment shall be capable of conducting the maximum fault current that could flow at the point of grounding for the time necessary to clear the fault. c. Impedance. Temporary protective grounding equipment and connections shall have an impedance low enough to cause immediate operation of protective devices in case of unintentional energizing of the electric conductors or circuit parts.
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They modified this section.
In earlier versions, this section was designated as 120.5. However, after revisions in the 2024 version, it has been renumbered to 120.6.
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