Do I Need an Arc Flash Study?


This is a common question to ask yourself when considering electrical hazards in the workplace. Power system studies, commonly referred to as “arc flash studies” are paramount to the safety of electrically qualified workers. Proper PPE selection and job safety planning rely on the results of such a study, which when paired with proper training to recognize and address the hazards can help avoid potential injuries before they happen.

In fact, OSHA requires that employers assess the workplace for hazards and can continue to levy fines against companies that have failed “to provide a workplace free from hazards that could seriously harm workers,” or where inspections reveal that workers have not had adequate training. OSHA 1910.331 and 1910.332 address the requirements for workers who are employed near electrical hazards, in addition to the training required to stay safe on the job.

Excel Engineering has a dedicated team of experts ready to help you assess the proper actions needed to keep your workers safe and your business in compliance with industry standards. Here, we take a look at whether or not you’re required to have an arc flash study, what it entails, and the benefits and costs of doing so.

Am I Required to Have an Arc Flash Study?

OSHA addresses the requirements for workers who are employed near electrical hazards and the training required to work safely on the job.

Per OSHA’s standards:

  • 132(d)(1): The employer shall assess the workplace to determine if hazards are present, or are likely to be present, which necessitate the use of personal protective equipment (PPE). If such hazards are present, or likely to be present, the employer shall:
    • 132(d)(1)(i): Select, and have each affected employee use, the types of PPE that will protect the affected employee from the hazards identified in the hazard assessment.
    • 132(d)(1)(ii): Communicate selection decisions to each affected employee; and,
    • 132(d)(1)(iii): Select PPE that properly fits each affected employee.
  • 335(b)(1): Safety signs and tags. Safety signs, safety symbols, or accident prevention tags shall be used where necessary to warn employees about electrical hazards which may endanger them, as required by § 1910.145.
  • Specific to Electric Arcs:
    • 269(l)(8)(i): The employer shall assess the workplace to identify employees exposed to hazards from flames or from electric arcs.
    • 269(l)(8)(ii): For each employee exposed to hazards from electric arcs, the employer shall make a reasonable estimate of the incident heat energy to which the employee would be exposed.

Note 1 to paragraph (l)(8)(ii): Appendix E to this section provides guidance on estimating available heat energy. OSHA deems employers following the guidance in Appendix E to this section to be in compliance with paragraph (l)(8)(ii) of this section. An employer may choose a method of calculating incident heat energy not included in Appendix E to this section if the chosen method reasonably predicts the incident energy to which the employee would be exposed.

Note 2 to paragraph (l)(8)(ii): This paragraph does not require the employer to estimate the incident heat energy exposure for every job task performed by each employee. The employer may make broad estimates that cover multiple system areas provided the employer uses reasonable assumptions about the energy-exposure distribution throughout the system and provided the estimates represent the maximum employee exposure for those areas. For example, the employer could estimate the heat energy just outside a substation feeding a radial distribution system and use that estimate for all jobs performed on that radial system.


OSHA enforces its own standards that relate to electrical hazards. OSHA may, however, use
NFPA 70E to support citations for violations relating to certain OSHA standards, such as the general requirements for personal protective equipment found in 29 CFR 1910.335.

OSHA views NFPA 70E as the primary consensus standard for addressing electrical hazards associated with electrical utilization systems.

NFPA 70E (2021) 130.5(G) states that the incident energy analysis shall be updated when changes occur in the electrical distribution system that could affect the results of the analysis. The incident energy analysis shall also be reviewed for accuracy at intervals not to exceed five years.

IEEE-1584 (2018) defines the methods by which hazard levels are determined, providing techniques for designers and facility operators to apply in determining the arc flash hazard distance and the incident energy to which employees could be exposed during their work on or near electrical equipment.

Arc flash studies can vary in scope depending on who is performing the work. Some consultants may only provide enough information to label equipment. While this may satisfy regulatory requirements, there are more facets to a study that can provide crucial data on your electrical system and that can help prevent costly downtime.

Excel Engineering’s Power Systems Group has performed thousands of arc flash studies all over the U.S. for large and small facilities alike. Our team of engineers can provide your staff with cost-effective, accurate, and concise information that will assist you in developing a safer, more efficient, and more reliable electrical distribution system. We also help uncover valuable information for your workers’ safety.

What Are the Benefits of an Arc Flash Study?

The benefits of performing an arc flash study are multi-faceted. In addition to helping workers exposed to electrical hazards properly address the hazards and select proper PPE, the analysis of your electrical system can also yield several other advantages.

Many distribution systems can harbor unforeseen deficiencies that may impact proper selection of required PPE, such as underrated short circuit overcurrent protective devices and mis-coordinated overcurrent protective schemes.

Correcting these issues before they happen can prevent undue interruptions in power, and potentially devastating injuries and possibly equipment damage. The arc flash study can identify these issues and allow you to be proactive in preventing system failures.

Updated and current facility single diagrams also are updated during an arc flash study, and these documents play a vital role in the routine maintenance and design of the facility electrical power distribution system. 2021 NFPA 70E 205.2 requires that a single line diagram, where provided for the electrical system, shall be maintained in a legible condition and kept current.

Excel Engineering’s experienced staff can tailor our arc flash study services to be a cost-effective tool. The study can reveal potential deficiencies such as underrated overcurrent protective devices and mis-coordinated overcurrent devices, which could lead to unnecessary downtime, or worse: workers who are unprepared for potential electrical hazards.

What Does an Arc Flash Study Entail?

In general, a consulting firm performing an arc flash study will examine and document the electrical distribution system in your facility. This can take anywhere from 1-2 days to upwards of 3 weeks depending on the size of the facility. In some situations, equipment may need to be de-energized to safely gather the necessary information. Typically, the data gathering process does not interrupt integral facility processes.

An arc flash study typically includes:

  • Gathering information about system, utility, main switchgear, breakers, and conductors.
  • Developing a model using software developed for analysis.
  • Performing a short circuit evaluation.
  • Perform an equipment evaluation.
  • Identifying PPE levels and requirements.
  • Developing and reviewing a summary report.
  • Printing and applying labels to equipment.
  • Providing training for affected workers.

Once the data has been gathered, it should be analyzed by qualified people to develop and provide necessary and concise information in a report.  It is vital that the results of the study become integrated into the facilities’ safety policies and procedures. IEEE-1584 (2018), the “Guide for performing Arc Flash Hazard Calculations,” is the standard guiding consultants.

How Much Does an Arc Flash Study Cost?

The cost of an arc flash study can vary widely based on the scope of work and the size and location of the facility. For large facilities, studies can be done in phases. Typical costs can be anywhere in the range of $5,000-$100,000.

Excel Engineering’s staff can provide you with summarized information to aid in crucial facility decisions about maintaining the safety and reliability of the electrical distribution system, in addition to providing training to your workers. Our training offerings center around and focus on the most current OSHA and NFPA 70E requirements. Safe work practices and policies can prevent accidents and ensure workers are protected from the potential deadly nature of electrical hazards. We’re here to assist your workers in understanding and recognizing the hazards they face when working with energized equipment.

Contact us today to learn more.

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