This standard describes certain electrical, mechanical, and safety requirements and conformance tests for dry-type distribution and power transformers and for auto transformers. These transformers may be either single-phase or polyphase, with ventilated, non ventilated, or scaled enclosures.
Such transformers may be remotely or integrally associated with primary or secondary switchgear or substations, or both. The range of transformers is 601 volts through 34 500 volts (either primary or secondary) in sizes of 1 kVA through 2 500 kVA. Such transformers are intended to be installed in accordance with the American National Standard National Electrical Code (ANSI/NFPA 70-1987). All manufacturers seeking certification under this standard should demonstrate that performance requirements have been met by performing the tests herein, by submitting data from earlier tests, by exhibiting proof of satisfactory field service, or by an appropriate combination of these methods. Families of insulation systems may be certified on the basis of tests performed on one representative model.