Arc-flash incident energies and boundary distances can be calculated in a variety of ways. For example, you can use the equations from IEEE Standard 1584. The IEEE 1584 established nine-steps in the arc flash hazard analysis process, namely:
Calculations made using these guidelines are expected to be accurate because they are based on a large number of tests. However, there is no 100% accurate method for determining the degree of exposure that workers may face. The equations given in IEEE Std. 1584 are based on experimental 208V to 15kV laboratory tests. Three sets of equations are provided for the three distinct voltage ranges: 208V to 600V; 1kV to 15kV; and above 15kV. The actual radiated energy could be higher than the values yielded from the IEEE 1584 equations. The environment in which the arc takes place affects the arc-flash energy level. Factors like humidity, contaminants, temperature, enclosure type, and material consumed in the arc will affect the radiated energy level. In addition, other factors like power factor, the length and impedance of the arc, and the duration of the arc also come into play.
ARCAD's arc flash software calls for you to enter the fault level, voltage, the equipment configuration, distance from an expected arc to the worker and select upstream protection device. It then calculates the incident energy level and boundary distance for this specific location on the system. You would use this data to create the labels required to be placed on the electrical equipment.
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