IEEE C57.91-1981 - IEEE Guide for Loading Mineral-Oil-Immersed Overhead and Pad-Mounted Distribution Transformers Rated 500kVA and Less with 65 C or 55 C Average Winding Rise
Standard Details
General recommendations for loading 65 degrees Centigrade-rise mineral-oil-immersed overhead and pad-mounted distribution transformers are covered. Recommendations for 55 degrees Centigrade-rise transformers are included because a substantial percentage of these transformers are still in service. The recommendations are based on winding hottest-spot calculations only. Other factors that may limit the permissible load to lower values are listed. A method to establish winding temperature and loss of life by nomographs is given.
Sponsor Committee
Status
Superseded by
Board Approval
History
Additional Resources Details
Pars
Working Group Details
Working Group
Working Group Chair
Sponsor Committee
Society
IEEE Program Manager
Active Projects
Existing Standards