A disconenct is never required by code for the secondary of a transformer. The transformer secondary and/or the secondary conductors may require overcurrent protection.
Don
Both Charlie and Don are correct ... it is semantics, a play on the language used.
If I can take a little liberty here, what I believe charlie meant is that based on table 450.3(B), you may have a disconnect on the secondary side of the transformer.
What Don meant is that the secondary of a transformer itself never has a disconnect.
Pierre,
You are exactly correct. I didn't know what the real question in the original post was asking. Charlie answered based on overcurrent protection and I answered based on a disconnet switch.
don