IEEE C57.12.00-2021

This standard describes electrical and mechanical requirements of liquid-immersed distribution and power transformers, and autotransformers and regulating transformers, single-phase and polyphase, with voltages of 601 V or higher in the highest voltage winding. This standard applies to all liquid-immersed distribution, power, and regulating transformers that do not belong to the following types of apparatus: a) Instrument transformers; b) Step voltage and induction voltage regulators; c) Arc furnace transformers; d) Rectifier transformers; e) Specialty transformers; f) Grounding transformers; g) Mobile transformers; h) Mine transformers