This standard is intended to set forth characteristics relating
to performance, limited electrical and mechanical
interchangeability, and safety of the equipment described herein,
and to assist in the proper selection of such equipment.
This standard describes certain electrical and mechanical
characteristics and takes into consideration certain safety
features of three-phase, 60-Hz, two-winding, ventilated dry-type
network transformers generally used for step-down purposes,
high-voltage 34 500 volts and below; low-voltage 216Y/125 and
480Y/277 volts with self-cooled ratings 2500 kVA and smaller.
Forced-air ratings are listed in Part II.
This standard does not apply to other types of transformers,
such as specialty, sealed dry-type, pad-mounted dry-type,
liquid-immersed, instrument, regulating, furnace, mine, and
rectifier transformers. Transformers with high voltage 600 volts or
less are excluded.
As used in this standard, the word ?shall? indicates mandatory
requirements, and the words ?should? and ?may? refer to matters
that are recommended and permissive, respectively, but not
NOTE - The Foreword of this standard describes the circumstances
under which the document may be used on a mandatory basis.
Part I of this standard describes electrical and mechanical
requirements. Part II describes other requirements or alternatives
that may be specified.