Electrical, mechanical, and safety requirements are set forth for liquid-immersed distribution and power transformers, and auto transformers and regulating transformers; single and polyphase, with voltages of 601 V or higher in the highest voltage winding. This standard is a basis for the establishment of performance, limited electrical and mechanical interchangeability, and safety requirements of equipment described; and for assistance in the proper selection of such equipment. The requirements in this standard apply to all liquid-immersed distribution, power, and regulating transformers except the following: instrument transformers, step-voltage and induction voltage regulators, arc furnace transformers, rectifier transformers, specialty transformers, grounding transformers, mobile transformers, and mine transformers.

This standard is a basis for the establishment of performance, limited electrical and mechanical interchangeability, and safety requirements of equipment described; and for assistance in the proper selection of such equipment. This standard describes electrical, mechanical, and safety requirements of liquid immersed distribution and power transformers, and auto transformers and regulating transformers; single and polyphase, with voltage 601 V or higher in the highest voltage winding. This standard applies to all liquid-immersed distribution, power, and regulating transformers except as indicated below: (1) Instrument transformers (2) Step-voltage and induction voltage regulators (3) Arc furnace transformers (4) Rectifier transformers (5) Specialty transformers (6) Grounding transformers (7) Mobile transformers (8) Mine transformers When this standard is used on a mandatory basis, the words shall and must indicate mandatory requirements; and the words should and may refer to matters that are recommended or permissive, but not mandatory.