Arc Flash is the result of a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, neutral or a ground. During an arc fault the air is the conductor. Arc faults are generally limited to systems where the bus voltage is in excess of 120 volts.
- Data is collected about the facility’s power distribution system. The data includes the arrangement of components on a one-line drawing with nameplate specifications of every device.
- Also required are details of the lengths and cross section area of all cables.
- The utility company is also contacted for information pertaining the minimum and maximum fault currents that can be expected at the entrance to the facility.
Once the data has been collected, a short circuit analysis followed by a coordination study should be performed. The resultant data is then fed into the equations described by either NFPA 70E-2000 or IEEE Standard 1584-2002.
These equations will produce the necessary flash protection boundary distances and incident energy to determine the minimum PPE requirement.