American National Standard for Transformers—230 kV and Below 833 / 958 through 8333 / 10 417 kVA, SinglePhase, and 750 / 862 through 60 000 / 80 000 / 100 000 kVA, Three-Phase Without Load Tap Changing; and 3750 / 4687 through 60 000 / 80 000 / 100 000 kVA with Load Tap Changing— Safety Requirement。