Thanks for the followup, SJT. On occasion, with a 2-wire primary, some forget that a 3-wire 1ø secondary cannot rely solely on the primary-overcurrent device for secondary overcurrent protection.
Also, if the proposed 15kVA unit was delta-wye or delta-delta powered only on two primary phases, weird voltages may have been present on the resulting 120/208Y 3-wire or 120/240 3-wire circuit, particularly with increasing load.
