Re: Secondary Transformer Protection
Blackowl, there are only two conditions where the transformer secondary conductors are not required to have protection.
1. A transformer with a 2-wire primary and a 2-wire secondary, and the primary is protected the in accordance with 450.3.
2. A 3 phase, delta-delta-connected transformer having a 3-wire, single voltage secondary, provided its primary is protected in accordance to 450.3.
Since you have a delta/wye transformer you need secondary protection. Refer to 240.4(F), 240.21(C), and 450.3.... Dereck