FAQ

An arc flash study analyzes your electrical distribution system to determine the incident energy and required personal protective equipment (PPE) at each piece of equipment. It identifies the potential severity of an arc flash event so equipment can be properly labeled and personnel can work safely. OSHA requires employers to protect workers from electrical hazards, and NFPA 70E is the industry standard for meeting that obligation, making an arc flash study a practical requirement for any facility with employees working on or near energized equipment. Insurance carriers may also require a current arc flash study as part of their underwriting requirements.

A third-party review is an independent audit of engineering work performed by another firm, such as an arc flash study, short circuit analysis, or coordination study. It checks the model inputs, assumptions, calculation methods, and conclusions to confirm the work is accurate. This is commonly requested for quality control, peer review requirements, litigation support, or simply as a second opinion.

Fosco Engineering primarily serves data centers, industrial facilities, and commercial and institutional buildings. We also partner directly with electrical contractors, providing studies and calculations without requiring an in-house engineering department.

Deliverables vary depending on project needs. Often, deliverables include a full written report with action items. This report includes electrical one line diagrams, short circuit study, arc flash study, TCC curves, and recommendations for device coordination when applicable. If necessary, printed arc flash labels can be supplied.

NFPA 70E recommends reviewing arc flash studies at least every five years to account for changes in equipment and utility fault current. A study should also be updated sooner whenever there is a significant change to the electrical system such as new equipment or a change in the utility service size.

Absolutely yes. The utility transformer nameplate information (winding configuration, primary/secondary voltage, kVA/MVA, %Z impedance) are key drivers of fault current throughout the facility. Any change to the utility transformer affects everything downstream.

They often go hand-in-hand, as an arc flash study cannot be performed without a short-circuit study. A short circuit study calculates the available fault current at each point in your electrical system. This is used to verify that equipment is rated to safely interrupt or withstand a fault (kAIC rating). An arc flash study uses the calculated fault current at each piece of equipment, along with protective device coordination data, to calculate incident energy and determine the required PPE category.

Studies are performed in accordance with the most recent versions of NFPA 70E for electrical safety in the workplace, IEEE 1584 for arc flash hazard calculations, and the National Electrical Code (NEC) for system design requirements. All modeling and analysis is performed using industry-standard software like SKM and ETAP.

At minimum, we need accurate one-line diagrams, equipment nameplate data (transformers, protective devices, and cables), and utility fault current data. If as-built documentation is incomplete, we can coordinate field data collection.

This depends on each facility size and the completeness of existing documentation. Contact us with your project details for a specific estimate.

Yes. Every study includes NFPA 70E-compliant arc flash labels for each piece of equipment analyzed, ready to print and apply in the field.

Deliverables vary depending on project needs. Deliverables typically include a full written report documenting the scope of review, findings, and any inadequacies identified. Where issues are found, the report includes specific recommendations for correction. If the original study needs no correction, the report serves as independent documentation confirming its accuracy.

A third-party review makes sense any time you need independent verification of engineering work. Often, a third-party review is part of a project scope. Other instances include quality assurance or when a study is being challenged or scrutinized. It is also useful when inheriting studies performed by a previous firm.

The value of a third-party review isn't knowing in advance what we'll find — it's having someone independent verify the study before you find out the hard way. Third-party reviews commonly surface a mix of data, methodology, and formatting issues. Findings run from minor data entry errors to significant miscalculations.

We work directly with you, the client. Depending on the scope, that can include coordinating with the original engineering firm to obtain source files and clarify assumptions, but our review and findings are delivered independently to protect the integrity of the assessment.