chapter  14
Loading and Thermal Performance
Pages 12

ANSI standards collection for the C57 series sets forth the general requirements for the design of power

transformers. With respect to loading, the requirements of concern are those that define the transfor-

mer’s thermal characteristics. The average ambient temperature of the air in contact with the cooling

equipment for a 24-hr period shall not exceed 308C, and the maximum shall not exceed 408C (IEEE,

1994). For example, a day with a high temperature of 358C and a low of 258C has an approximate

average ambient temperature of 308C.