NFPA 70E: Raising the standard
The latest updates to NFPA 70E require plant managers to re-examine their electrical safety programs.
Plant Engineering will present a Webcast on October 22nd that will discuss changes in NFPA 70E for next year. To register for the Webcast, click the link HERE.
Every three years, the National Fire Protection Association updates NFPA 70E: Standard for Electrical Safety in the Workplace. The intent of the standard is to reduce exposure to the hazards of shock, electrocution, arc flash, and arc blast while working on or near exposed electrical conductors or circuit parts that are or can become energized. With greater overall energy usage, higher system voltages, and higher available fault current, the risk of such exposure is on the rise, forcing plant managers to make significant changes and updates to their electrical safety policies to comply.
Failing to make the necessary changes can, and does, have dire consequences for employees and businesses. In addition to claiming one life every workday, arc flash incidents can also lead to business disruption, equipment damage, legal liability, increased insurance premiums, and regulatory fines.
For example, a recent arc flash incident in Buffalo, N.Y., caused an electric technician to suffer third-degree burns on her hand and first-degree burns on her face because her employer failed to provide proper face and hand protection. That employer faces a proposed fine of $147,000 from OSHA. In another recent incident in Florida, lax enforcement of safety policies led to the electrocution of an electrician's apprentice by more than 10,000 V. The utility company faces proposed penalties totaling $90,000. OSHA fines following arc flash incidents are just the beginning of the costs for employers, as many subsequently face expensive litigation, possible increases in insurance premiums, and likely, some equipment repair.
Clearly, failure to properly protect workers from arc flash hazards can exact a cost no plant wants to pay. The key to saving lives, preventing serious injuries, and avoiding costly business disruptions begins with understanding the latest changes and updates to NFPA 70E along with what your plant needs to do to comply. This article will review the standard's newest guidelines for identifying and assessing arc flash risks, communicating those risks, and training workers. It will also introduce best practices for creating a safe electrical work environment that is up to code.
Identifying and assessing arc flash risks through engineering analysis
OSHA has always made it the employer's responsibility to identify and share on-the-job risks and hazards with employees, including arc flash risks. To help accomplish this, NFPA requires plant managers to perform an arc flash risk assessment prior to allowing workers to perform tasks on or near energized equipment.
In the 2012 version of NFPA 70E, a major revision stated that the arc flash boundary distance must be determined for all locations where the voltage is greater than 50 V and there is a possibility of performing energized work such as maintenance, diagnostics, and testing. This requirement significantly expanded the scope of arc flash risk assessments.
Furthermore, the 2015 version of the standard limited the use of the Arc Flash PPE (personal protection equipment) Categories Method-or table method-for determining the arc flash boundary distance. Specifically, the tables supplied in the standard may only be used in situations where 1) the specific task to be performed appears in the tables, and 2) the system meets the listed criteria for short-circuit current magnitude and speed of response of circuit protection. In many cases, facility managers do not have access to the data and information needed to use the tables correctly.
As a result, most plant managers will need to use the more rigorous engineering analysis method to complete the arc flash risk assessment and calculate the arc flash boundary distance. This method involves reviewing technical data and using software to perform calculations, which is obviously more work than consulting the standard's tables.
However, while engineering analysis is more costly and likely more time-consuming to implement, it does generate site-specific results that can better protect facilities and workers, especially when considering that tables are often misused in the field. The extra effort of engineering analysis could even save a life.
Effectively communicating arc flash risks with workers
Once an arc flash risk assessment has been completed, it's up to the plant manager to share the results with workers so they can use the information to properly protect themselves on the job. To facilitate communication, both NFPA and OSHA require employers to meet with contract employees to share information about known hazards. Those meetings must now be documented to ensure compliance.
Additionally, owners of ac and dc electrical equipment are responsible for properly field labeling the equipment with arc-flash-hazard warning labels that include the results of the arc flash risk assessment. Arc flash equipment labeling first became an NFPA 70E requirement in 2002, and the requirements have been updated in 2004, 2009, 2012, and 2015. The standard now spells out the types of equipment that need to be labeled, including switchboards, switchgear, panel boards, industrial control panels, meter socket enclosures, and motor control panels-any equipment likely to require examination, adjustment, servicing, or maintenance while energized.
The new standard also makes it clear what information needs to be on field labels, including nominal system voltage and arc flash boundary, along with information employees can use to select the appropriate PPE:
- If the engineering analysis method is used to calculate the arc flash boundary, labels must include the calculated incident energy (in calories per square centimeter at working distance). Workers can then select PPE with an arc rating that meets or exceeds the incident energy value posted on the arc-flash-hazard label.
- If the table method is used to determine PPE requirements (which requires knowing the short-circuit magnitude and clearing time), then the equipment label needs to include the PPE category indicated by the tables. Workers must then consult a different table to select the right PPE.
Beyond properly labeling electrical equipment, owners of the equipment are also responsible for keeping the labels up to date. It's important to remember that even small changes to the electrical distribution system-like replacing a fuse or circuit breaker-have the potential to impact the accuracy of arc flash labels, and thus, the risk to electrical workers. To ensure compliance and keep workers safe, arc flash assessments and label reviews should be completed when any changes are made, or at least once every 5 yr.
Training workers to identify and mitigate arc flash hazards
Properly labeling electrical equipment with hazard information and providing workers with the right PPE for the job can go a long way toward keeping workers safe, but only if those workers know how to read the labels and use the PPE. NFPA 70E includes specific guidelines for properly training workers to identify and assess electrical and arc flash hazards and to select and use the right PPE.
The most recent versions of the standard include updates on when and how training should be conducted, as well as requirements for ensuring workers have the skills they need to stay safe. Since arc flash can create a blast strong enough to injure someone standing more than 10 ft from the fault source, training must be provided for employees who work around-and not just on-energized equipment. Preferably, the training should be provided via an instructor-led course as opposed to Web-based training. Workers must be retrained (not just refreshed) at least every 3 yr, and the safety policies and training program must be audited at least every 3 yr. To ensure compliance, all training activities and audits must be documented.
The 2012 version of NFPA 70E introduced the requirement for annual worker audits. These audits are intended to ensure that each employee is complying with safety-related work practices. The audits provide plant owners with the opportunity to observe and document each worker's ability to identify a risk, quantify the magnitude of the hazard, and properly use PPE in a real work environment. The audits can give invaluable insight into whether or not workers have the qualifications needed to stay safe on the job.
Working with a trusted engineering or testing partner to achieve compliance
Clearly, to comply with the latest versions of NFPA 70E, plant managers have their work cut out for them. Many will need to conduct complex engineering analyses in multiple locations, overhaul their equipment-labeling programs, update training policies, and develop worker-audit programs.
While there is no legal requirement for a registered professional engineer to perform arc flash hazard analysis, such a partner can be instrumental in ensuring the accuracy of the results, interpreting the analysis, and using the information to develop more effective safety programs for your plant. With the assistance of a well-qualified engineering or testing company, you will be well on your way to ensuring regulatory compliance and creating a safer work environment.
Wally Vahlstrom is director of technical services for Emerson Network Power's Electrical Reliability Services division. He is responsible for failure-investigation work, conformity-assessment services, power-system studies, and reliability analysis.
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