The Wye service transformer has three 120-V windings, which are 120 degrees apart. The names come from the secondary winding configuration, which looks like a “Y” or three-sided star (Figure 1). For ...

Section 450.3(B) covers the protection of the transformer windings, not the conductors supplying or leaving the transformer. For currents of 9A or more, Sec. 450.3(B), Note 1 applies. Where 125% of ...