All steps of a real-world arc flash calculation example of a low-voltage AC installation with transformer, main switchboard, and distribution boards are explained.

One of the main factors determining the severity of an arc flash injury is the proximity of the worker to the arc flash, also known as the working distance. Working distances from AS (ENA), IEEE, NFPA and DGUV Standards and Guides have been provided.

Electrical equipment operating at or above 50 V AC or 120 V DC which will not put into a deenergised state during work must be evaluated for arc flash and shock protection. Three types of activities of workers carry the highest risk of arc flash. Three main factors determine the severity of an arc flash injury.