I take back my earlier mention of 14-100(d) for the following reason.
14-100(d) can not apply as its subrule (ii) requires that the circuit teminate at a single overcurrent device, which in this case we do not have.
So it looks like...
As per rule 26-258(2a) the minimum ampacity of the secondary conductors must be sized at 125% of the transformer's rated secondary current.
Good catch Bill, your comment made me rethink this.
