I had tried down load the attachment with my NEXUS7 but it failed to download and I can't see why. I'll look at it with my PC
Also, since I was and application engineer I do have some data that I put together regarding inrush. As a rule of thumb as the kva of a transformer is increased the % inrush of the FLA decreases. The inrush also varies at a given KVA depended upon the transformer efficiency, 'k' factor, and temperature rise.
I finally downloaded the schematic. In my opinion you do need secondary protection however I find that the secondary connections to the transformer very strange.
I find that should you connect X2 and X3 which is OK and the connect XI to X2/X3 it is a direct short circuit of the X1-X2 winding as well as the connection between X4 to X2/X3 we which is a direct short of the X3-X4 winding.
It is of my opinion that the connection between X-1 and X2/X3 be removed as well as the connection between X4 to X3/X3 removed also.
Then the connection between X2-X3 becomes the neutral and the point which is grounded.
The X1 is fused and X4 is fused. The voltage between X1 and X2/X3 is 120v and X4 and X2/X3 is 120v. Between X1 and X4 is 240v.
The the secondary fused are based upon 104FLA. x 125% or 130a. Because you are providing secondary protection you are allowed up to 250% of the primary 52FLA.
I see that the primary fusing is 50A and the secondary fuses 25a. Why? Am I missing something? Have I misunderstood the purpose of the secondary connection?