IEEE C57.154-2012 pdf download IEEE Standard for the Design, Testing, and Application of Liquid-Immersed Distribution, Power, and Regulating Transformers Using High-Temperature Insulation Systems and Operating at Elevated Temperatures
3.Definitions
For the purposes of this document, the following terms and definitions apply. For other terms, the standardtransformer terminology in IEEE Std C57.12.80 shall apply. Other electrical terms are defined in the IEEEStandards Dictionarv Online
conventional: A description applied to temperature-rise limits, insulation materials or insulation systemsoperating at temperatures within the normal thermal limits ofIEEE Std C57.12.00.
NOTE–The thermal limits for the winding are defined as 65 °C average temperature rise, 80 °C hottest spottemperature rise, and 110 °C hottest spot temperature. The thermal limits for the insulating liquid are defined as 65 °top oil temperature rise.
conventional insulation system: Solid insulation materials used throughout the transformer and insulatingliquid, operating at temperatures within the normal thermal limits of IEEE Std C57.12.00.
NOTE–The thermal limits for the winding are defined as 65 °C average temperature rise, 80 C hottest spottemperature rise, and 110 °C hottest spot temperature. The thermal limits for the insulating liquid are defined as 65 top oil temperature rise.
full hybrid insulation winding: A winding composed of conventional solid insulation with hightemperature solid insulation used in areas in contact with the winding conductor to allow higher tharconventional average winding and hottest spot temperature rises
high-temperature: A description applied to temperature-rise limits,insulation materials or insulationsystems operating at higher temperatures than conventional.
high-temperature insulation svstem: High-temerature insulation used throughout the transformerexcept for some minor insulation components in lower temperature areas, together with high-temperatureinsulating liquid operating at higher than conventional top liquid, average winding and hottest spottemperature rises.
high-temperature insulation winding: A winding composed of high-temperature insulation usedthroughout the winding to allow higher than conventional average winding and hottest spot temperaturerises.
hybrid insulation system: High-temperature solid insulation operating above conventional temperaturescombined with conventional solid insulation and an insulating liquid operating at conventionaltemperatures
mixed hybrid insulation winding: A winding composed of conventional solid insulation with hightemperature solid insulation used only selectively to allow higher than conventional hottest spottemperatures, while operating at conventional average winding temperature rises
reference temperature: The standard temperature to which calculations and measurement are referredshall be defined as 20 °C plus the base rated average winding rise. For multiple winding transformers thathave more than one base rated average winding rise, the highest average winding rise shall be used todetermine the reference temperature.