Arc Flash Standards
NFPA 70E is the Standard for Electrical Safety in the Workplace. This is a document that is published by the NFPA and is not an OSHA document. It is also not a part of the NEC previously mentioned, but is instead a self-contained document.
NFPA 70E 2012 Article 90.2(A) States:
Covered. This standard addresses electrical safety-related work practices for employee workplaces that are necessary for the practical safeguarding of employees relative to the hazards associated with electrical energy during activities such as the installation, inspection, operation, maintenance, and demolition of electric conductors, electric equipment, signaling and communications conductors and equipment, and raceways. This standard also includes safe work practices for employees performing other work activities that can expose them to electrical hazards as well as safe work practices for the following:
Installation of conductors and equipment that connect to the supply of electricity.
Installations used by the electric utility, such as office buildings, warehouses, garages, machine shops, and recreational buildings that are not an integral part of the generating plan, substation, or control center.
As you can see from this scope of the standard, it is much different that the NEC. This is a document that is much more concerned with protecting workers through safe work practice not necessarily just proper design and installation. The NFPA 70E clearly calls out the hazards of Shock, Electrocution, Arc Flash, and Arc Blast and gives direction on how to properly protect workers from each of these standards.
The NFPA 70E has not been formally adopted by OSHA at this time, but there is a great correlation and relationship between the standards. OSHA standards basically tell you what you must do, and the NFPA 70E tells you how to do it.
European Arc Flash Standard IEC 60298
IEC standards are used predominantly in Europe and have trickled into many other parts of the world. IEC stands for International Electrotechnical Commission (IEC). The IEC is a non-profit institution much like the NFPA and IEEE in the U.S., that is responsible for establishing electrical standards throughout the world.
IEC 60298 is the equivalent of NFPA and IEEE standards that the U.S. is familiar with, and is followed throughout Europe and much of the rest of the world. The electrical systems and design practices in Europe are so different from U.S. and North American standards, it is hard to make a direct comparison of the content. If you would like more information you can visit the IEC website directly.
Canadian Standards Association(CSA) Z462-12
The CSA Z462 is essentially a direct copy of the U.S. NFPA 70E standard with minor alterations to better reflect the Canadian workplace, and coincide better with other existing CSA electrical standards.
Clause 220.127.116.11 in Z462-12 details the arc flash equipment labeling requirements. You will notice the the Z462 standard identifies the exact requirements as the NFPA 70E but makes one addition - (d) date of the hazard analysis.
The Z462 labeling requirements are:
Electrical equipment such as switchboards, panelboards, industrial control panels, meter socket enclosures, and motor control centers (MCCs) that are in other than dwelling units and that are likely to require examination, adjustment, servicing, or maintenance while energized shall be field marked with a label containing all the following information:
- Available incident energy and the corresponding working distance
- Minimum arc rating of clothing
- Required level of PPE
- Date of the hazard analysis
- Highest Hazard/Risk category (HRC) for the equipment
- Nominal system voltage
- Arc flash boundary
The Canadian Standards Association website states that the second edition (Z462-12) provides:
- Advice on integrating electrical safety programs into OHS management systems
- Best safety practices for work on and around electrical equipment
- Guidance on due diligence in prevention of electrical injuries
- Methods for identifying electrical hazards and assessing risk
- Targets for electrical hazard awareness and training for workers CSA Z462-12 includes the following changes that are related to arc flash:
Arc Flash Boundary:
CSA Z462 re-names the "arc flash protection boundary" as the "arc flash boundary".
Z462-12 provides a definition of the "arc flash boundary" as establishing a hazard zone (a conceptual boundary) around potentially hazardous electrical equipment. It specifies that the "arc flash boundary" either be calculated or be obtained from the applicable Hazard/Risk Category Table.
PPE Tables for Use with Incident Energy Calculations
A new table is available to help employers determine what PPE should be specified on arc flash labels. The new table is designed to identify required arc flash PPE by its energy rating instead of by category number. This is being done in order to move away from using the hazard category number for determining the required PPE.
"Hazard" and "Risk" - These are now two distinct terms.
In the previous version of Z462 the terms "hazard" and "risk" were used interchangeably and were sometimes combined into a single term; "hazard/risk." CSA Z462-12 brings the use of these terms in line with how they are used in international safety standards.
Safety management systems recognize that "hazards" should be identified and eliminated whenever possible. On the other hand "risk" is to be reduced such that it is effectively controlled. This results in an elimination and control strategy for electrical safety. This change in terminology puts the focus first on eliminating or controlling hazardous energy. When that is not possible, then PPE is used to protect workers.
New Terminology: "Arc-Rated" Protective Equipment
CSA Z462-12 adds a new term: "arc-rated". This term is used to distinguish PPE that provides arc flash protection from PPE that provides flame resistance or flash-fire resistance (FR rating). CSA points out that "the arc-rating assigned to protective equipment should not be confused with the arc flash incident energy calculated or estimated for electrical equipment (circuits). The former refers to the amount of protection offered while the latter refers to the nature of the hazard".
New Worker Training Requirements
CSA Z462-12 changes the training requirement from requiring "periodic training" to a requirement for training every three years.