1.1 These requirements cover single-phase or three-phase, dry-type, distribution transformers, including solid cast and resin encapsulated transformers. The transformers are provided with either ventilated or non-ventilated enclosures and are rated for a primary or secondary voltage from 601 to 35000 V.

1.2 These transformers are intended for installation in accordance with the National Electrical Code, ANSI/NFPA 70.

1.3 These requirements do not cover the following transformers:

1. a) Instrument transformers

2. b) Step-voltage and induction voltage regulators

3. c) Current regulators

4. d) Arc furnace transformers

5. e) Rectifier transformers

6. f) Specialty transformers (such as rectifier, ignition, gas tube sign transformers, and the like)

7. g) Mining transformers

8. h) Motor-starting reactors and transformers

1.4 These requirements do not cover transformers under the exclusive control of electrical utilities utilized for communication, metering, generation, control, transformation, transmission, and distribution of electric energy regardless of whether such transformers are located indoors, in buildings and rooms used exclusively by utilities for such purposes; or outdoors on property owned, leased, established rights on private property or on public rights of way (highways, streets, roads, and the like).