Historical
IEEE C57.109-1993 (R2008)
IEEE Guide for Liquid-Immersed Transformers Through-Fault-Current Duration
Recommendations believed essential for the application of over current protective devices applied to limit the exposure time of transformers to short-circuit current are set forth. Transformer coordination curves are presented for four categories of transformers. There is no intent to imply overload capability.
Institute of Electrical and Electronics Engineers [ieee]