Arc Flash in National and International Standards and Rules

The electrical arc flash hazard is increasingly recognised in industry standards and rules. Whilst overarching health and safety legislation (such as the Electricity at Work Regulations 1989 in the UK or OSHA 29 CFR 1910 Subpart S in the USA) tend to cover the hazard of arc flash in a non-prescriptive way, industry standards and rules are often much more specific about how to address the hazard posed by arc flash. This page gives a summary of standards and rules that we have come across with a brief description of how they cover arc flash and what the requirements are.

If you have any other examples of arc flash appearing in national or international standards or similar documents please get in touch with us so that we can add it to this page.

Onshore

NFPA 70E

Standard for Electrical Safety in the Workplace

This American standard covers electrical safety in industry but excluding certain sectors such as marine and utilities.

In Section 130.5 (A) General it calls for an arc flash risk assessment to be performed to "identify arc flash hazards", estimate the likelihood and severity of an incident and "determine if additional protection measures are required, including PPE".

In subsequent parts (B) through (H) it contains more detailed information on selection of PPE, labelling and calls for the Incident Energy analysis and the data supporting the labelling to be "reviewed for accuracy at intervals not to exceed 5 years".

The Informative Annex D discusses several Incident Energy and Arc Flash Boundary Calculation Methods which may be used: the the Ralph Lee Method, the Doughty Neal Method, the IEEE 1584 Method and the Direct Current Method. Equations, examples and data are provided throughout.

Offshore

IEC 61892-2

Mobile and Fixed Offshore Units - Electrical Installations - Part 2: System Design

This IEC standard, which is implemented in various countries (e.g. in the UK as British Standard BS IEC 61892-2), is intended to "enable safety in the design of electrical equipment for the generation, storage, distribution and utilisation of electrical energy for all purposes in offshore units, which are being used for the purpose of exploration or exploitation of petroleum resources".

Section 9.1 General Requirements for System Study and Calculations states that: "flash hazard risk assessment should be considered for switchboards".

It goes on to say that "Arc-flash calculations and tagging should be perfomed as described in IEEE 1584, or in corresponding IEC Standards". It has notes for various mitigation measures that could be used to reduce the arc flash hazard including minimising fault currents, minimising fault durations, considering remote operation and providing specific input information to incorporate arc flash into operation risk assessments.

It says that NFPA 70E may be consulted for determining requires for PPE and also states that the arc incident energy exposure for "electrical systems where people are performing maintenance/repair work or operating electrical equipment should be limited to 8 cal/cm²."

Marine

Lloyd's Register

Rules and Regulations for the Classification of Ships (July 2021)

These rules are very clear about the requirement to assess electrical equipment for arc flash hazards with Part 6, Chapter 2, Section 8 Protection from electric arc hazards within electrical equipment covering this topic in detail.

In summary, this Section requires that the arc flash hazard be identified and assessed in accordance with an acceptable standard (e.g. IEEE 1584) for all electrical equipment within which an arcing fault could occur, including motor starter panels, switchboards and transformers. The consequences should be determined and it must be demonstrated that adequate measures have been taken to reduce the risk of injury to personnel. To support this work, calculations to determine maximum fault current, Incident Energy and the Arc Flash Boundary should be completed and submitted.

American Bureau of Shipping

Rules for Building and Classing Mobile Offshore Units (2022)

Part 6, Chapter 1, Section 7 covers arc flash requirements with respect to Switchgear and Control-gear Assemblies operating at voltages >1000V:

15.3.2(f) covers Arc Flash and Associated Installation Requirements with (ii) detailing a requirement for calaculations in accordance with applicable parts of Standard IEEE 1584 to establish the maximum current that can flow in the case of an arc fault, the maximum time and current that could flow if arc protection techniques are adopted, and the distance from the location of the arc flash at which the arc flash energy would be 1.2 calories per cm² if the enclosure is open.

In (iii) it also adds that arc flash data consistent with the Design Operating Philosophy and the required PPE is to be indicated at each location where work on the HV equipment could be conducted.

PPE Standards

Number	Title	Last Updated
ANSI/ISEA Z89.1-2014	American National Standard For Industrial Head Protection	2014
ANSI/ISEA Z87.1-2015	American National Standard For Occupational And Educational Personal Eye And Face Protection Devices	2015
ASTM F2178-12	Standard Test Method for Determining the Arc Rating and Standard Specification for Eye or Face Protective Products	2012