Grounding HV Transformer

[augie47]

(From member IM)
I am just wanna be sure this 2.5MVA transformer primary terminal grounding and bonding is ok - there’s a #4/0 green grounding stubbing up into the chamber from the below ground loop which will be tied to the case on a vendor provided Nema 2-hole pad. The 15kV shields will be also bonded to pad along with the #2/0 EGC routed within the conduit.
We always focus on the secondary side but just wondering if the case should be bonded to the grid or does it even matter?

 

[ron]

The size and voltage doesn't change the basics.

The enclosure gets bonded to be part of the fault path.

 

[electrofelon]

(From member IM)
I am just wanna be sure this 2.5MVA transformer primary terminal grounding and bonding is ok - there’s a #4/0 green grounding stubbing up into the chamber from the below ground loop which will be tied to the case on a vendor provided Nema 2-hole pad. The 15kV shields will be also bonded to pad along with the #2/0 EGC routed within the conduit.
We always focus on the secondary side but just wondering if the case should be bonded to the grid or does it even matter?

The only possible concern I would have is I believe sometimes the MV shield is only connected at one end of IIRC. Whether this is done or not effects shield currents and thus the ampacity of the cable. I am not a MV guy so take this cum grano salis.