Arc Flash Standards
Regulation for electrical safe working in both US (NFPA 70E) and Europe (EN 50110) require a risk assessment for electrical hazards including arc flash. Although the latter seems very general compared to the more detailed and specific requirements of its US counterpart, the possible methods for assessing and controlling arc flash risk are similar for both.
An overview of the main standards and how they relate to arc flash risk:
IEEE 1584
IEEE 1584 Guide for Performing Arc-Flash Hazard Calculations provides a method for calculating arc flash hazard for electrical distribution systems.
NFPA 70E
NFPA 70E: Standard for Electrical Safety In the Workplace is a standard intended for use by employers and employees to comply with OSHA requirements for electrical safety.
EN 50110
EN 50110 Operation of Electrical Installations is a European Standard that sets requirements for the safe operation of and work performed on electrical installations in CENELEC countries.
BGI/GUV-I 5188 E
BGI/GUV-I 5188 EThermal Hazards from Electric Fault Arc is a document provides guidance on how to select class 1 or 2 arc flash PPE tested with the box method.
This document provides guidance on how to select PPE that has been tested against IEC 61482-1-2, also known as the box method. This method does not result in a withstand value in cal/cm², but instead classifies PPE as class 1 or 2. A direct conversion between these classes and an ATPV in cal/cm² is not possible.
The guide gives a basic calculation method for determining if class 1 or 2 protection is required. The calculation is based on electrical system properties including the fault clearing time, but arcing currents are taken as simply half the short-circuit current. From tests performed for IEEE 1584 we know that the arcing current can be much lower than half the short-circuit current. This can lead to severely underestimating fault clearing time and arc flash incident energy. It is strongly discouraged to use this method for calculating arc flash hazards.
Other Standards
ASTM F1506, F1449, F2757: Performance requirements and guides for care of arc rated textile materials.
ASTM F2178: Test method for determining arc rating of eye or face protective products.
ASTM F1891: Standard specification for arc and flame resistant rainwear.
EN 61482-1-1: Test method for arc rating of protective clothing. This test is similar to ASTM F1506 and results in an ATPV – a value in cal/cm² that can be used with IEEE 1584 hazard study results.
EN 61482-1-2: Alternative test method called the box test that assigns class 1 or 2 to protective clothing. BGI/GUV-I 5188 E gives guidance on selecting protective clothing with this designation.
