How is incident energy calculated?

Incident energy is calculated using a combination of electrical system data and assumptions about the arc flash event. The following factors are taken into account when calculating incident energy:

1. Available fault current: This is the maximum amount of current that can flow through a circuit in the event of a fault, such as a short circuit.
2. Duration of the fault: This is the amount of time that the fault current flows before it is interrupted by a protective device, such as a circuit breaker.
3. Distance from the arc: This is the distance between the worker and the arc flash event, which affects the amount of energy that reaches the worker.
4. Arc gap: This is the distance between the conductors that create the arc, which affects the energy released during the arc flash.
5. Equipment type: Different types of equipment have different levels of resistance to electrical arcs, which affects the amount of energy released during an arc flash.

Once these factors are determined, the incident energy can be calculated using a variety of methods, including software programs, tables, and equations. The results of the incident energy calculation are then used to determine the appropriate level of PPE for workers in the area.

Related Standards/FAQ

• What is the purpose of an arc flash study?
• What is an arc flash study?
• How is incident energy calculated?
• What is incident energy?
• What is the difference between arc flash PPE levels and incident energy?
• What is the difference between arc flash PPE levels and arc flash boundaries?
• What is the difference between PPE categories and arc flash PPE levels?
• What are the NFPA 70E requirements for arc flash protection?
• What are the OSHA requirements for arc flash protection?