Calculating transformer OCPD over 1000v primary

[Jpflex]

My company has a delta delta 300 KVA 4800 Volt primary 480 Volt secondary 3 phase transformer with an impedance of 4.3%

I noticed in NEC table 450.3 A, that when sizing OCPD for primary conductors it seems to matter where this transformer is located.

If located at any location a circuit breaker at 600% of transformer rated current

Or if located in a supervised location a circuit breaker at 300% of transformer rated current could be used

BUT WHO OR WHAT CODE determines where the transformer is to be located? Our business is going to have this installed in the open on company private property without fencing as far as I know?

Also I can’t find a specific NEC CODE dictating how the primary conductors must be sized at or calculated but only OCPD. I hate assuming and just sizing breakers to match OCPD or coming up with something else

 

[Jpflex]

Also the book says OCPD is to be installed in series with each Primary phase conductor, so is this referring to the utility cutouts?

I haven’t before seen any device or panel preceding transformer primary connections where such fuses can be installed?

How do you go about this? Thanks