Please give me some insite if Cal#2 rated clothing is what we need to work on 480 volt three phase live. With covers off and live part exposed.
No idea what cal#2 means. There is HRC 2 clothing requirements Arc rated clothing is rated in cal/cm2, sounds like you have them confused.
As far as you question, no, no one can, the PPE requirements are based off the available fault current and clearing times, on 480V systems that can be anywhere between just cotton clothing to beaing so dangerous there is no PPE in the world that will protect you.
But, you cannot just work on something live because you want to, you need justfication to work energized and if you can justify it you need an Energized work permit, which requires a risk analysis.
I suggest you get some 70E training, at least start by reading the FAQ's in the safety section of this forum.