Working Group Details
InsLife-WGC57.91 - Insulating Life - Loading Guide Working Group
|Working Group Chair||
|IEEE Program Manager|
This guide provides recommendations for loading mineral-oil-immersed transformers and step-voltage regulators with insulation systems rated for a 65 ?C average winding temperature rise at rated load. This guide applies to transformers manufactured in accordance with IEEE Std C57.12.00 and tested in accordance with IEEE Std C57.12.90, and step-voltage regulators manufactured and tested in accordance with IEEE Std C57.15. Because a substantial population of transformers and step-voltage regulators with insulation systems rated for 55 ?C average winding temperature rise at rated load are still in service, recommendations that are specific to this equipment are also included.
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
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.
General recommendations for loading 65 C rise mineral-oil-immersed distribution and power transformers are covered.
IEEE C57.91-1995/Cor 1-2002 - IEEE Guide for Loading Mineral-Oil-Immersed Transformers - Corrigendum 1
Errors identified in IEEE Std C57.91-1995 are addressed in this corrigendum.