Errors identified in IEEE Std C57.91-1995 are addressed in this corrigendum.
- Sponsor Committee
- PE/TR - Transformers
Learn More - Status
- Superseded Standard
- PAR Approval
- 2000-03-30
- Board Approval
- 2002-12-11
- History
-
- Published:
- 2003-06-12
- Reaffirmed:
- 2004-06-24
Working Group Details
- Society
- IEEE Power and Energy Society
Learn More - Sponsor Committee
- PE/TR - Transformers
Learn More - Working Group
-
InsLife-WGC57.91 - Insulating Life - Loading Guide Working Group
Learn More - IEEE Program Manager
- Malia Zaman
Contact - Working Group Chair
- David Wallach
PC57.91
Guide for Loading Mineral-Oil-Immersed Transformers and Step-Voltage Regulators
This guide provides recommendations for loading mineral-oil-immersed transformers and step-voltage regulators with insulation systems rated for a 65 u00b0C 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 u00b0C average winding temperature rise at rated load are still in service, recommendations that are specific to this equipment are also included.
No Active Standards
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.
C57.91-1995
IEEE Guide for Loading Mineral-Oil-Immersed Transformers
General recommendations for loading 65 C rise mineral-oil-immersed distribution and power transformers are covered.
No Inactive-Withdrawn Standards
C57.91-2011
IEEE Guide for Loading Mineral-Oil-Immersed Transformers and Step-Voltage Regulators
This guide provides recommendations for loading mineral-oil-immersed transformers and step-voltage regulators with insulation systems rated for a 65 u00b0C average winding temperature rise at rated load. This guide applies to transformers manufactured in accordance with IEEE Std C57.12.001 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 u00b0C average winding temperature rise at rated load are still in service, recommendations that are specific to this equipment are also included.