The Value of an Arc Flash Study

In Depth, From the Inside Out

Ed McConnell, SSOE Group

Today’s bids are becoming more competitive and owners are increasingly asking for arc flash studies to be included in the bid, rather than outsourced.  This creates a challenge for the firms doing the bidding, as it can take a significant effort to price out a bid for arc flash.

Sometimes the owner views arc flash as an add-on, believing as a result that the update shouldn’t take much more effort. However, the update cannot always be considered an add-on or compartmentalized into a small part of the plant; a small change can have a large impact across the system.

Because it can be unpredictable, bid packages must provide clear details so clients understand what it entails and what costs are involved.

In this way, firms and clients can go into the process with a full awareness of the costs and effort required for arc flash and there are fewer surprises.

This search for a helpful solution is important because people have routinely put off such activities in the past until they reach a crisis point.  Even as they are beginning to recognize the importance, the industry standards are becoming stricter.

Growing awareness is driving many companies to prioritize, a topic that isn’t new but is suddenly coming to the forefront.

The Process

Leaders who are still growing in their understanding of the process, from start to finish, may think that if they present files and drawings to the design team, it is just a matter of data entry and calculation, but there is much more to it than that.

Every change must be field verified, which is a time-consuming process, with field verifications for installed equipment including breaker settings, name plate ratings, feeder length, electrode type, enclosure size, and cable type—all required pieces of information that take special expertise to obtain.

Far beyond data entry, teams aim to understand the specifics of the electrical system and incorporate that into the model, as they enter detailed information that will contribute to a complete picture.

 After the field verification and data entry, iterative calculations create system output for analysis.  This analysis considers the available fault and current, the time to interrupt the fault, and the resultant incident energy and arc flash boundary. At this point, many of the variables are set by the system, but the time to interrupt the fault may be able to be impacted. Project teams coordinate the various overcurrent protection devices used to mitigate the effects of a potential fault on system performance so that those devices closest to the fault open fastest.

Communicating the equipment data is important. Printing labels for each piece of equipment is essential for keeping a record of the data analysis and communicating the hazard risk at the equipment.  Information from these labels can also be entered into 3D models so the electronic record matches what is installed.  Teams use the software capabilities available to them to get the most accurate information for safety requirements, such as PPE requirements and hazard notifications for protecting users.

This level of safety due diligence can be a part of normal operations, but often projects focus on meeting code in the most cost-effective way first. In fact, having the safest and most reliable information to protect staff, visitors, and contractors on site is well worth the additional investment. 

An emphasis on safety can even be a key selling point for owners if the project team is known for going above and beyond.


An arc flash study is an important part of the owner’s safety program. The intricacies of the process require a certain level of competence to get the job done right, which can be impacted by following issues.

Although most companies avoid implementation of new processes as long as possible, a routine audit or other review may bring an important issue to the forefront.  At that point, stakeholders need sound data for an informative and smooth transition process.  They may have little to no experience and need to determine where they are at present and what they need to reach their goals, as well as what potential caveats there may be, all in accordance with the schedule for ongoing projects.

One of the challenges is bringing in unfamiliar contractors and subcontractors when work load is high.  In those situations, a project team mentality is vitally important and team members aim for transparency and collaboration in resolving any problem that emerges.

However, unfamiliar contractors and their subcontractors haven’t been brought up in the same culture, so their attention to safety protocols, procedures, and mindset could be different from the core team’s.  In a true team atmosphere, no one has neither hesitation nor reservations about asking questions to move the entire effort forward more quickly and effectively—and safely.

It can be challenging to advise corporate and/or division managers of the impact of safety issues because every situation has a unique set of competing priorities and pressures from different sources.  If the goals and desires of stakeholders exceed their comfort zone or the guaranteed maximum price for the project, they will be forced to revisit their priority list.

Decision makers can increase their flexibility by re-evaluating their positions on certain matters.  For example, a leader that had historically rejected aluminum conductors for the electrical system in their building was convinced to reconsider when they analyzed the cost difference between copper and aluminum, which was close to $750,000 for a new project.

On the other hand, cost-saving decisions like this can impact the safety of the design because going from copper to aluminum conductors changes the way the electrical current is conveyed through the system, which could raise arc flash incident energy.

Surprises can emerge in many projects. They can flourish especially when dealing with projects and installations that take place in foreign countries. No matter what, project teams must coordinate engineering support for each new utility service.  A good working relationship with the local electrical power provider needs to be established early, with a chain of communication set up and the channel kept open to reduce delays.


Municipalities are there to help and communication is key: designating an account manager to get the required information to them in the timely manner helps the process run smoothly.

Project teams that are helping stakeholders navigate the process should be abreast of any changes that take place in the industry.  For example, IEEE1584 was recently updated with new calculations, so associated projects are integrating the changes into the calculations for updates every 5 years or so.  The calculation method has changed drastically based on how cables enter and terminate at the equipment and the results generated are much different.

Because it has become more complex, the process to complete a study also takes longer and costs more.  Most leaders need some education and even those who do understand and have the means to perform the tasks in-house often subcontract it for the sake of time.

Even the savviest decision makers may budget for what they know from the past and find that the cost is higher in today’s marketplace so they must plan accordingly.
Purchasing power has become paramount for decision makers and they need solid data to make clear cost comparisons amidst competitive bidding. In these situations, trust is crucial for successful partnerships.  Established relationships held over from previous projects can form the basis for future partnerships, especially in unfamiliar territory.

It is challenging to sell a whole new set of skills to a new client with no relationship or trust, so finding the common ground and building from there is critical.
One way stakeholders can save money is by tailoring the level of service to meet, but not exceed, the project’s needs.

For example, a project that involves a full-blown 2,000 page booklet and updated one-lines for a 15-floor hospital is vastly different from a manufacturing client who already has files that were updated 5 years ago and wants to check those for updates, calculation, and input to see if it is necessary to revise the labels on equipment.  Experienced project teams know what questions to ask leaders to right-size the project to their needs.

To determine the level of need, project teams can ask decision makers what brought the reevaluation to their attention in the first place.  Sometimes the impetus sheds light on the true need: was the idea brought to them by an inspection on a small renovation or are they addressing a significant addition?

Leaders can tend to feel apprehensive about spending money on something that wasn’t in the initial budget to rectify something an inspector pointed out, so teams who are brought in can show interest and a desire to help by asking questions to determine root cause.  In this way, they can also get an idea of the project scope and assure the stakeholders they will stay within the boundaries set forth by the initial project plan.

Corporate decision makers often are included at the decision point to give their approval and it helps to have a clear report or executive summary that can be passed up to management to have the expense justified.

Ideally project team leaders will act as a commodity service offering a service bundle, but it is also good to provide individualized options for those instances where decision makers are better off choosing from a list of available options so they only get what is necessary.

Secure and Confident

While this creates some extra initiatives for leaders, ultimately it will mean vast improvements for the industry as a whole by reducing death and injuries related to electrical shock and arc flash hazards.

These are rare but when they do happen, people are directly impacted, and safety rises to the top of the priority list industry-wide and companies are reminded of the virtues of a proactive approach versus a reactive one.

Building a foundation of guidance, and delivery of all the relevant information in a timely fashion will help clients feel secure and confident as they implement new initiatives.

About the Author

Ed McConnell, PE, is a master engineer and senior associate at SSOE Group, a global project delivery firm for architecture, engineering, and construction management. With over 40 years of experience, Ed specializes in facility electrical power distribution, large motor starting, lighting, electrical systems grounding, building grounding, building utilities electrical power and control, substations, security systems, communication systems, and fire detection and alarm systems. His experience includes electrical power system analysis (Arc Flash) and design in hazardous areas such as Class I and Class II environments. He can be reached at

Subscribe to Machinery Lubrication

About the Author