Arc Flash Guide April 2014

ARC FLASH LABELING GUIDE A GUIDE TO PROPERLY LABELING ARC FLASH HAZARDS ACCORINDING TO NFPA 70E® OSHA requires safe work practices, but it is the National Fire Protection Association's standard NFPA 70E®: Standard for Electrical Safety in the Workplace® that specifies safe work practices when arc flash is a hazard. 2009 NFPA 70E®: Standard for Electrical Safety in the Workplace® NFPA 70E Article 130.3(C) requires arc flash warning labels to include, at a minimum, the arc flash incident energy or required level of PPE. Warning labels must be posted on each piece of electrical equipment that may be worked on while energized, or when verifying power is off. Unfortunately, putting only the minimum required information on the label can leave workers without essential information. It makes more sense to include all of the information, including incident energy, hazard risk category, required level of PPE and the specific PPE items required. In addition, it is good practice to include shock and flash protection boundaries, available fault current, voltage level and assessment date. Sample Arc Flash Hazard Label WARNING Flash Hazard Boundary Arc Flash protection boundary is an approach limit at a distance from exposed live parts within which a person could receive a second degree burn if an electric arc flash were to occur. Required PPE (Personal Protective Equipment) Employees working in areas where electrical hazards are present are to be provided with and use protective equipment that is designed and constructed for the specific part of the body to be protected and for the work to be performed. Arc Flash & Shock Hazard Appropriate PPE Required ARC FLASH PROTECTION BOUNDARY AND REQUIRED PPE Flash Hazard Boundry: Incident Energy at 18" (cal/cm2): 16.4 Incident Energy Incident Energy is a measure of thermal energy at a working distance from an arc fault (measured in cal/cm2). The working distance is the distance from where the worker stands to the flash location (commonly 18 inches). The incident energy is a function of system voltage, available short-circuit current, arc current, and the time required for circuit protective devices to open. Glove Class Electrical safety gloves are categorized by the level of voltage protection they provide and whether or not they're resistant to ozone. Voltage protection is broken down into six classes. Class 00 is the least protective, while class 4 provides the most protection. Hazard Risk Category: Class 3 Glove Class: 00 Required PPE: Cotton Underwear + FR shirt & Pants + FR Coverall Hazard Risk Category The Hazard Risk Category level is determined by ATPV (Arc Thermal Performance Value). ATPV is the measure (in cal/cm2) of how much heat can be exposed to a flame resistant garment before a second degree burn injury is expected to occur. HRC is based on specific job tasks and ranges from HRC 0 (which is low risk and allows for 100% untreated cotton), up to HRC 4 (which is high risk and requires flame resistant clothing with a minimum arc rating of 40). 89 inch SHOCK HAZARD PROTECTION BOUNDARIES Shock Hazard: 480 VAC Limited Approach: 42 inch Restricted Approach: 42 inch Equipment ID: Bus: C-H Prot: MCB C-H Prohibited Approach: 1 inch Assessment Date: 6/12/11 Shock Hazard Shock Hazard, measured in VAC, is a dangerous electrical condition associated with the possible release of energy caused by contact or approach to energized parts. Limited Approach The limited approach boundary should be entered only by qualified persons or unqualified persons that have been advised and are escorted by a qualified person. Restricted Approach The restricted approach boundary should be entered only by qualified persons. Requires the use of shock protection techniques and PPE Prohibited Approach The prohibited approach boundary should be entered only by qualified persons. Requires same protection as if in direct contact with live part. Assessment Date Arc flash hazard assessment must be reviewed at least every 5 years or when a major modification occurs. This means that the label should include a documented date. Creative Safety Supply | phone: [phone] | fax: [phone] www.creativesafetysupply.com | email: [email protected]