3/21/2024 0 Comments Arc flash boundary detailsEntering the Limited Approach Boundary:.Where one or more unqualified persons are working at or close to the limited approach boundary, the alerting methods shall be applied to advise the unqualified persons of the electrical hazard and warn him or her to stay outside of the limited approach boundary. Working at or Close to the Limited Approach Boundary:.No unqualified person shall be permitted to approach nearer than the limited approach boundary of energized conductors and circuit parts. Nominal system voltage is recorded in Volts and can be displayed as V, VAC or VDC (VAC = volts alternating current, VDC = volts direct current). Leather footwear 6.Shock Hazard Voltage.Arc-rated gloves or rubber insulating gloves with leather protectors (Selection Required)Īrc-Rated Clothing Selected, So That the System Arc Rating Meets the Required Minimum Arc Rating of 40 Cal/cm2 (167.5 J/cm2).Arc-rated Arc Flash suit pants (As Required).Arc-rated Arc Flash suit jacket (As Required).Arc-rated long-sleeve shirt (As Required).Heavy-duty leather gloves, arc-rated gloves, or rubber insulating gloves with leather protectors (SelectionĪrc-Rated Clothing Selected, So That the System Arc Rating Meets the Required Minimum Arc Rating of 25 Cal/cm2 (104.7 J/cm2).Arc-rated jacket, parka, high-visibility apparel, rainwear, or hard hat liner (As Needed).Arc-rated flash suit hood or arc-rated face shield and arc-rated balaclava.Heavy-duty leather gloves, arc-rated gloves, or rubber insulating gloves with leather protectors (Selection Required)Īrc-Rated Clothing, Minimum Arc Rating of 8 Cal/cm2 (33.5 J/cm2).Safety glasses or safety goggles (Selection Required).Arc-rated jacket, parka, high-visibility apparel, rainwear, or hard hat liner.Arc-rated face shield or Arc Flash suit hood.Arc-rated long-sleeve shirt and pants or arc-rated coverall.PPE categories range from 1 to 4 (with four having the highest incident energy rating and requiring the most protective gear).Īrc-Rated Clothing, Minimum Arc Rating of 4 Cal/cm2(16.75 J/cm2) The Arc Flash Personal Protective Equipment (PPE) Category is determined by consulting the PPE tables in article 130.7 of the NFPA 70E standard. The incident energy is reduced as the working distance is increased. Because the worker is closer to the possible arc point, reducing this working distance increases incident energy. The computation is based on the working distance, and if you work from a different working distance, the incident energy values will change. The arc source is usually energized parts within an equipment enclosure or exposed energized parts in open air. Parts of the body closer to the potential arc source other than the face and chest receive a greater incident energy. It is the distance between the potential arc source and the face and chest of the worker performing the task. Workers must wear PPE’s based on categories which are mentioned in Arc Flash label. The units used to measure incident energy are joules per square centimeter (J/cm2) or calories per square centimeter (Cal/cm2). Incident energy increases as the working distance from the potential arc source decreases, and the incident energy decreases as the distance increases. The incident energy is calculated at the working distance. The amount of thermal energy impressed on a surface, a certain distance from the source, generated during an electric arc event. Workers inside the Arc Flash boundary must have to wear with proper PPE Mentioned in the Arc Flash Label for Arc Flash protection. Arc Flash BoundaryĪ distance from a prospective arc source at which the incident energy is calculated to be 5.0J/cm2(1.2cal/cm2). It’s a warning intended to get your attention and alert you to potential dangers. It is important to understand the information given on the label to protect yourself and others Sample Arc Flash LabelĪ warning label appears at the top of the label. Arc Flash labelling requirements are defined by the newly updated NFPA 70E 2021 standard. National Fire Protection Association (NFPA) was developed at Occupational Safety and Health Administration’s (OSHA) request and sets the standards for electrical safety in the workplace. Arc Flash/shock hazard warning labels are specifically designed to help protect qualified workers who are doing live maintenance in the Switch gear, MCCs, PCCs and DBs have to examine, adjust, service or maintain electrical equipment while energized.
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