10.1.1 – Incident Energy vs Table Method

There are two primary methods that can be used when determining the Arc Flash Boundary:

a) The Incident Energy Analysis Method – this formulae for arc in open air:

Taken from Annex D 3.1.2 equation D1.

alternatively, IEEE 1584 calculations can be used

• The incident energy analysis shall take into consideration the characteristics of the overcurrent protective device and its fault clearing time, including its condition of maintenance.

• The incident energy analysis shall be updated when changes occur in the electrical distribution system that could affect the results of the analysis. The incident energy analysis shall also be reviewed for accuracy at intervals not to exceed 5 years.

The Incident Energy Analysis Method is used by Master Electricians and Electrical Engineers in determining the values for Arc Flash stickers to go on the equipment.

b) The Arc Flash PPE Selectin Table Method

When the arc flash PPE selection method is used for the selection of PPE for ac systems in lieu of the incident energy analysis method specified in Clause 4.3.5.6.2, Table V.1 or Table V.2 shall be used to determine the arc flash PPE minimum arc rating.

Table V.1 – Alternating current equipment types, voltage classifications, and parameters are listed in Table V.1 and the associated notes. Table V.1 shall not be used where the listed parameters are exceeded or for equipment types and classifications that are not listed.