Transformer Secondary

[cwhite6]

We have a 225kVA, 34.5kv/480V 3 phase delta-Wye transformer in a substation we are building. The transformer is fused on the high side at 150% per table 450.3(A) in the 2014 NEC. We used the "Any" row for the impedance. The secondary conductors go to feed a building outside of the substation fence. At the building, the conductors enter a wall mounted 600V disconnect that has 250 amp fuses. The cable is sized appropriately per the code. Do we need secondary fuses at the transformer?

 

[cwhite6]

As more info to above, Per 240.21 (C) 4, it appears I do not need these fuses. The secondary cable is installed in schedule 80 PVC underground from the transformer to the mentioned wall mounted disconnect. The only load it feeds is the building. There are no taps.

 

[charlie b]

I agree. No fuses are needed at the secondary of the transformer.

Welcome to the forum.

 

[cwhite6]

Thanks Charlie!!