How To Calculate ARC Flash

An arc flash is a dangerous burst of electricity that can occur on the job for people who work with electricity and equipment such as electrical transformers. While it is never a substitute for proper safety precautions, an arc flash calculator can help determine the size and energy of a possible arc that can occur. Based on this information, along with what you already know about the job, you can get an idea of what to watch out for and how to protect against it.

Step 1

Open an online arc flash calculator. Two free arc flash calculators are located in the Resource Section below.

Step 2

Choose the type of equipment you are using from the drop down box labeled "Equipment Type" or choose from the drop down box labeled "Equipment Class." The terms may vary depending on the calculator, but the first option will always ask you to choose the type of equipment you're working with.

Step 3

Choose the correct values for the choices given, such as "Bolted Fault" and "Clearing Time." Depending on the type calculator you are using, you may be given drop down, sliders or blank boxes to use for inputting additional information. Certain calculators offer more choices than others, depending on how complex you want your calculations to be.

Step 4

Click the "Calculate" or "Calculate Arc Flash" button once you have filled out all the requested information. Your results will be displayed either above or below the calculator. It will give information about the arc flash itself, and possibly recommend the type of safety gear needed for the given situation.