Arc Flash Consulting Services

An arc flash study is a detailed engineering analysis of an electrical power distribution system that evaluates the potential arc flash hazard associated with energized electrical equipment. The study includes collecting system data, developing or validating a power system model, calculating available fault currents, evaluating protective devices, determining incident energy levels, establishing arc flash boundaries, identifying PPE requirements, and developing equipment labeling recommendations. The results help improve worker safety, support compliance with NFPA 70E requirements, and identify opportunities to reduce arc flash hazards through engineering controls and protective device setting changes.

An arc flash study should be performed by qualified electrical power system engineers with experience in power system modeling, short-circuit analysis, protective device evaluation, and arc flash hazard assessments.

NFPA 70E Article 130.5 requires that an arc flash risk assessment be reviewed at intervals not to exceed five years. An update should also be performed whenever a major modification or renovation is made to the electrical distribution system that could affect arc flash hazards. Examples include:

• Service Upgrades
• Changes to Utility Fault Current
• Addition of Generators
• Installation of New Switchgear or MCCs
• Protective Device Setting Changes
• Significant Facility Expansions
• Addition or Removal of Large Motors

Arc flash studies are performed using industry-recognized standards and methodologies, including:

• IEEE 1584 - Guide for Performing Arc Flash Hazard Calculations
• NFPA 70E - Standard for Electrical Safety in the Workplace
• OSHA Electrical Safety Requirements
• National Electrical Code (NEC) Labeling Requirements

Arc flash calculations are typically performed using the current edition of IEEE 1584 and are used to support compliance with NFPA 70E electrical safety requirements, equipment labeling, and safe work practices.

The cost of an arc flash study depends on the size and complexity of your electrical distribution system. To develop an accurate estimate, we typically begin by reviewing your electrical one-line diagram. Factors that affect project cost include:

• Number of Substations, Switchboards, MCCs, and Electrical Panels
• Presence of Emergency or Standby Generators
• Availability and Accuracy of Existing Electrical Drawings
• Amount of Field Data Collection and Verification Required
• Inclusion of coordination studies, protective device setting reviews, or acr flash mitigation recommendations.

Facilities with accurate and up-to-date one-line diagrams generally require less field effort, which can help reduce project costs and schedule. After reviewing your one-line diagram, our engineers can provide a detailed scope and budget tailored to your facility.

Nee a budgetary estimate? Send us your current one-line diagram and our engineers will review your electrical distribution system to develop a scope, schedule, and budget tailored to your facility. If one-line drawings are unavailable or outdated, we can also discuss field verification options to support the study.

An arc flash study not only identifies hazards within your electrical distribution system, but can also uncover opportunities to reduce incident energy levels and improve worker safety. The most effective mitigation strategy depends on the specific configuration of your electrical system and the causes of the elevated arc flash hazard.

Common arc flash mitigation methods include:

• Adjusting protective device settings to reduce fault clearing times
• Replacing or upgrading obsolete breaks and protection devices
• Improving protective device coordination
• Installing zone selective interlocking (ZSI)
• Adding differential relaying or arc-resistant switchgear
• Implementing maintenance switches or energy-reducing active arc flash mitigation systems
• Modifying system configurations or operating modes
• Replacing underrated equipment identified during the study.
• Improving electrical equipment maintenance practices
• Establishing safer work procedures and employee training programs

Many arc flash hazards are directly related to how long it takes a protective device to clear a fault. Our reports include breaker setting recommendations that could lower incident energy levels and improve coordination without major equipment replacement. In other cases, equipment replacement or additional engineering analysis may be required to achieve meaningful reductions in arc flash exposure.

An arc flash study is only the first step in improving electrical safety. Once an arc flash study has been completed and equipment has been labeled, employees must be trained to understand and apply the results in the field. The study provides critical information such as incident energy levels, arc flash boundaries, available fault current, and PPE requirements, but employees need training to safely use that information during maintenance, troubleshooting, and electrical work. 

We recommend NFPA 70E Training immediately following an arc flash study

NFPA 70E electrical safety training teaches employees how to recognize electrical hazards, interpret arc flash labels, understand shock and arc flash boundaries, perform risk assessments, and select the appropriate personal protective equipment (PPE) based on incident energy levels or PPE categories. Training also covers safe work practices, lockout/tagout procedures, electrically safe work conditions, and the responsibilities of qualified electrical workers.  Employees who work on or near energized electrical equipment should receive NFPA 70E training that specifically addresses how to use arc flash study results, including reading equipment labels, understanding arc flash boundaries, determining PPE requirements, and following established electrical safety procedures. Workers must also understand the relationship between electrical hazards and potential injuries so they can make informed safety decisions in the field.  Organizations should also ensure that their electrical safety program, procedures, and employee training align with the findings of the arc flash study. This helps employees consistently apply the study results and maintain compliance with electrical safety requirements. 

One of the most common questions when planning an arc flash study is determining where to draw the line. Evaluating every piece of electrical equipment in a facility is possible, but it may not always be practical or cost-effective

One of the most common questions when planning an arc flash study is determining where to draw the line. Evaluating every piece of electrical equipment in a facility is possible, but it may not always be practical or cost-effective

The appropriate study scope depends on your facility, equipment, operating practices, and safety objectives. According to NFPA 70E, arc flash labels are required on equipment that is likely to require examination, adjustment, servicing, or maintenance while energized. As a result, the most important consideration is identifying the equipment your personnel may interact with while energized.

Common arc flash study scopes include:

• Distribution equipment only (switchgear, switchboards, MCCs, major distribution panels, and substations)
• Equipment fed from 40 amp or larger protective devices
• All equipment likely to require an energized work or troubleshooting
• Facility-wide studies that include distribution and utilization equipment

Our experience has shown that evaluating equipment fed from 40 amp or larger protective devices captures nearly all equipment that may present a meaningful arc flash hazard while maintaining a reasonable project budget. It is very uncommon for equipment below the 40-amp threshold to exceed 1.2 cal/cm², which is the incident energy level commonly associated with the onset of an arc flash hazard requiring arc-rated PPE.

However, there is no universal cutoff that applies to every facility. Factors such as available fault current, transformer size, conductor lengths, and protective device characteristics can affect incident energy levels. For that reason, facilities with unique electrical systems, high available fault current, or specific client standards may benefit from a broader scope of work.