Recommendations for operation and maintenance of dry-type distribution and power transformers are provided.

This recommended practice covers general recommendations for the application, installation, operation, and maintenance of all single and polyphase ventilated, non-ventilated, and sealed dry-type distribution and power transformers or autotransformers, including those with solid-cast and/or resin encapsulated windings except as follows: a) Instrument transformers b) Step- and induction-voltage regulators c) Arc-furnace transformers d) Rectifier transformers e) Specialty and general purpose transformers f) Mine transformers g) Testing transformers h) Welding transformers

The recommended practice is intended for general use in the application, installation, operation, and maintenance of dry-type transformers manufactured in accordance with IEEE Std C57.12.01, ANSI C57.12.50 [B1], ANSI C57.12.51 [B2], and ANSI C57.12.52 [B3]. Familiarity with other standards applying to dry-type transformers and to their protection is assumed and the provisions of those standards are indicated herein only for clarity.