This IEEE Standards product is part of the C57 Family on Power Distribution and Regulating Transformers.

This standard covers certain electrical, dimensional, and mechanical characteristics and takes into consideration certain safety features of 60-Hz, two-winding, liquid-immersed transformers rated as follows, and used for step-down or step-up purposes: a) 833/958 through 8333/10 417 kVA, single-phase; 750/862 through 10 000/12 500 kVA, three-phase; high voltage, 2400 through 138 000 volts; low-voltage, 480 through 36 230 volts—without load tap changing; b) 12 000/16 000/20 000 through 60 000/80 000/100 000 kVA, three-phase; high voltage, 23 000 through 230 000 volts; low voltage, 4800 through 36 230 volts—without load tap changing; c) 3750/4687 through 10 000/12 500 kVA, three-phase; high voltage, 6900 through 138 000; low voltage, 2400 through 36 230 volts—with load tap changing; d) 12 000/16 000/20 000 through 60 000/80 000/100 000 kVA, three-phase; high voltage, 23 000 through 230 000 volts; low voltage, 4800 through 36 230 volts—with load tap changing. It is not intended that this standard apply to dry-type, regulating, pad-mounted, secondary-network, furnace, rectifier, or mine transformers.

The purpose of this project is to update C57.12.10 and to remove any reference to distribution transformers which will be covered in a new stand alone standard, C57.12.36.