Good day all

In some cases, an arc flash study may need to be performed on some systems with generator supply.

I am curious how do you handle this , bearing in mind that the generator fault contribution happens over transient , sub-transient and steady states.

Higher fault currents (sub-transient) result in shorter tripping times hence lower incident energy values while lower fault currents (transient states) have longer trip times results in high incident energy values.

What is your approach when dealing with synchronous machine (generator supplies) with regards to arc flash studies ?

I would run both case scenarios and consider the worst case scenario for PPE selection and labeling. Please note that contrary to common belief and so called "scientific consensus", the highest incident energy does not necessarily mean the highest hazard. Please google "Evaluation of Onset to Second Degree Burn Energy in Arc Flash" for more information.