Electrical systems are constantly changing. Without a proper arc flash study, you won’t ever know the true danger level nor proper personal protective equipment (PPE) levels required to keep people safe. Quite often changes such as adding equipment to an existing system influence the arc flash energy levels, thus necessitating a study every time the system changes. Another example of changes to the system are when the utility company either changes transformers related to your facility or the closest substation undergoes changes, both of which drastically impact the arc flash energy levels.