IEEE C57.12.51-2008

This standard is intended to set forth characteristics relating to performance, limited electrical and mechanical interchangeability, as well as safety of the equipment described, and to assist in the proper selection of such equipment. Specific rating combinations are described in the range from 750/1000 kVA to 7500/10 000 kVA inclusive, with high-voltage 601 V to 34 500 V inclusive and low-voltage 208Y/120 V to 4160 V inclusive. This standard does not apply to other types of transformers such as specialty, ventilated dry-type 500 kVA and smaller, sealed dry-type, pad-mounted dry-type, liquid immersed, instrument, regulating, furnace, mine, and rectifier transformers. Transformers with high voltage 600 V or less are excluded. This standard describes certain electrical and mechanical characteristics and takes into consideration certain safety features of 60 Hz, two-winding, three-phase, ventilated dry-type transformers with self-cooled ratings 501 kVA and larger, which are generally used for step-down purposes. Forced-air-cooled ratings for certain sizes are listed in Clause 9. New IEEE Standard - Superseded. This standard is intended to set forth characteristics relating to performance, limited electrical and mechanical interchangeability, and safety of the equipment described, and to assist in the proper selection of such equipment. Specific rating combinations are described in the range from 750/1000 to 7500/10 000 kVA inclusive, with high-voltage 601 to 34 500 volts inclusive and low-voltage 208Y/120 to 4160 volts inclusive. Part I of this standard describes certain electrical and mechanical requirements and takes into consideration certain safety features of 60-Hz, two-winding, three-phase, ventilated dry-type transformers with self-cooled ratings 501 kVA and larger, generally used for step-down purposes. Part Il describes other requirements or alternatives which may be specified for some applications and lists forced-air-cooled ratings for certain sizes.