Live parts that operate at less than 50 volts to ground need not be deenergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs.(this was added)

Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations. In addressing work on electrical equipment, 1910.333(a)(1) states: The following sections of standard CFR Part 1910 promote the safety of employees working on or near electrical equipment, and clearly define employers' responsibilities:Įquipment must be deenergized before work is performed!

OSHA regulations were developed to mandate that employers provide a safe workplace for their employees. It is the end user and/or installer’s responsibility to properly specify the needed short circuit performance required. It is now clear in Article 409 and 670, that equipment installed under these sections must have a SCCR and or available fault current greater than the maximum available fault current at their location and have the equipment SCCR marked by the manufacturer. The following sections now call for proper field labeling of equipment with the maximum short circuit current available at the line terminals of that equipment: The first step in properly selecting adequate short circuit ratings is to know the available fault current. Over the past several cycles the NEC has added and modified sections to more effectively address this issue. Inadequate short circuit ratings (both AIR and SCCR) are on the list of causes of arc flash events. Section 110-16, Flash Hazard Warning, requires markings on switchboards, panelboards, industrial control panels and motor control centers to warn qualified persons of potential arc flash hazards. While the National Electrical Code (NEC) has traditionally addressed proper installation techniques intended to prevent fire, electrocution and shock hazard, it now contains requirements related to arc flash hazards. Selecting personal protective equipment (PPE) for workers.Performing electrical hazard and flash hazard analyses.Working involving electrical hazards, including:.Establishing electrically safe work conditions.A safety program with defined responsibilities.Developing safety-related work practices, including:.The Safety Related Work Practices chapter of NFPA 70E also provides guidelines for: Chapter 3: Safety Requirements for Special EquipmentĬhapter 1 outlines the requirements of employers whose employees are to work on equipment that has not been placed into an 'electrically safe work condition.' One of these requirements is to perform an arc flash risk assessment, which enables the employer to determine the magnitude of the arc flash hazard, the likelihood of injury and what protective measures are needed such as the type of PPE needed.Chapter 2: Safety Related Maintenance Requirements.Chapter 1: Safety Related Work Practices.See Ĭurrently NFPA 70E is organized into four chapters and a series of annexes designed to provide guidance on how to implement various aspects of an electrical safety program: With the inclusion of the risk control pyramid of ANSI Z10 (shown on the cover of the 2018 edition), employers are being directed to lower risks by considering options from the more effective methods at the top of the pyramid. The last two editions have significantly improved the coverage of risk management concepts. In the 1995 edition, arc flash hazards started to be addressed with addition of 'arc flash hazard boundaries.' Through extensive work, more details on protecting workers against arc flash hazards have been included in subsequent editions. The first several editions of the standard, originally titled 'Standard for Electrical Safety Requirements for Employee Workplaces,' primarily focused on the prevention of electrocution.

2018 nfpa 70e arc flash boundaries