Arc flash

Arc flash function allows users to calculate arc flash incident energy, flash boundary, both arc and fault currents, safe working distance. EA-PSM Electric calculations are validated in accordance with IEEE 1584 standard. It is possible to choose from different equipment types and calculate incident energy at any selected distance. Arc flash calculation results of EA-PSM Electric can be used to optimize protection devices and improve employees working conditions by minimizing arc flash hazard exposed energy and estimating safe working distance.

Arc flash is a release of the energy caused by an electric arc. It usually creates dangerous conditions for human personnel and equipment around the arc flash location, due to drastically increased temperature and pressure through the least resistance path in the air. Arc flash occurs during system faults, like short circuits, therefore, it is essential to disconnect the fault location from the voltage source in a timely manner before the short circuit develops into arc flash conditions. Because of this, arc flash hazards should be estimated when protection devices are coordinated.

Related safety recommendations as well as simple arc flash boundary calculation method is provided in NFPA 70E standard, while more accurate estimation of electric hazards are described in IEEE 1584.

Flash hazard analysis starts from data collection about the facility’s power distribution system configuration like parameters of cables, transformers, generators and other equipment, just like for the short circuit study. Then three-phase short circuit current is calculated as this type of short circuit represents the highest current. According to the calculated short circuit and NFPA 70E or IEEE 1584 recommendations, necessary flash protection boundary distance and incident energy to determine the minimum personal protective equipment (PPE) requirements are estimated.

It should be noted that arc fault current is less than the bolted fault current, therefore, improperly coordinate overcurrent protection devices possibly will not trip in case arc flash will occur. This is estimated in IEEE 1584 standard.