Power and Current Transformers. 9 questions
Power and Current Transformers. IEEE Standard C57.91-1995 (R2004), “Guide for Loading Mineral-Oil-Immersed Transformers” [Reference 3] recommends using “average daily temperatures” for the month involved in determining normal ratings and “average of maximum daily temperatures” for the month involved for emergency ratings. The Guide also recommends the use of a 5C adder to be conservative. The ambient temperatures indicated in Table A1 are consistent with the recommendations for determining ambient temperatures set forth in the C57.91 including the recommended 5C adder as based on the data of Table A2.
