{"schemaVersion":1,"slug":"transformer-winding-thermal-trip-interface","name":"Transformer winding thermal trip interface","kind":"symbol","abbreviation":"TWTTI","aliases":["Transformer protection and monitoring interfaces","substations Transformer protection and monitoring interfaces","substations","Substations","Winding thermal estimate","Winding-temperature trip initiation"],"category":"measurement-protection","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Carries the selected winding thermal protection result to the assigned trip logic.","description":["Carries the selected winding thermal protection result to the assigned trip logic. Transformer monitoring interfaces connect physical sensors and protection calculations to the station's alarms and trip logic. Temperature, oil, gas, pressure and electrical measurements indicate different conditions and require separate interpretation.","In a substation transformer bay, a protection panel receives winding-current measurements and equipment alarm contacts. An operator can then distinguish an electrical protection operation from a cooling-system or physical-condition alarm. For this reference, the drawing identifies “Winding thermal estimate” at the input and “Winding-temperature trip initiation” at the output. The thermal model requires transformer-specific data.","Identify the sensor or calculation, its monitored zone and its assigned response. Alarm and trip thresholds, sensor fitting and protection settings belong to the selected transformer documentation and the approved protection design. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation."],"readingNotes":["Start at the named input: Winding thermal estimate. Identify its source device or document and the state represented on the drawing.","Follow the named output: Winding-temperature trip initiation. Cross-reference its destination and separate the command from confirmation that the equipment responded.","The thermal model requires transformer-specific data.","Identify the sensor or calculation, its monitored zone and its assigned response. Alarm and trip thresholds, sensor fitting and protection settings belong to the selected transformer documentation and the approved protection design."],"drawingChecklist":["Label the source and connection reference for winding thermal estimate.","Identify the destination and defined state of winding-temperature trip initiation.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: The thermal model requires transformer-specific data."],"distinction":"The thermal model requires transformer-specific data. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.","facts":[{"label":"Representation","value":"Functional block"},{"label":"Installation focus","value":"Substations"},{"label":"Input / boundary","value":"Winding thermal estimate"},{"label":"Output / connection","value":"Winding-temperature trip initiation"},{"label":"Lookup label","value":"TWTTI is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"pi26-transformer-relay","relevance":"Public technical context for transformer protection and monitoring interfaces. Transformer protection, monitoring and measurement interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["power-transformer","87t-transformer-differential-protection","transformer-cooler-common-failure-alarm"],"artwork":"pi26-transformer-winding-thermal-trip-interface","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"substations","family":"transformer-monitoring","input":"Winding thermal estimate","output":"Winding-temperature trip initiation"},"plainEnglish":{"title":"What this block does","introduction":"Carries the selected winding thermal protection result to the assigned trip logic.","example":"In a substation transformer bay, a protection panel receives winding-current measurements and equipment alarm contacts. An operator can then distinguish an electrical protection operation from a cooling-system or physical-condition alarm. For this reference, the drawing identifies “Winding thermal estimate” at the input and “Winding-temperature trip initiation” at the output. The thermal model requires transformer-specific data.","drawings":"Start at the named input: Winding thermal estimate. Identify its source device or document and the state represented on the drawing. Follow the named output: Winding-temperature trip initiation. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Winding thermal estimate"},{"name":"Output","meaning":"Winding-temperature trip initiation"},{"name":"Application reference","meaning":"An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections."}],"diagram":"flow","steps":["Winding thermal estimate","TWTTI","Winding-temperature trip initiation"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"SEL-487E transformer protection relay","url":"https://selinc.com/products/487E/"}],"profileId":"power-installation-transformer-monitoring"},"url":"https://eloragrid.ai/symbols/transformer-winding-thermal-trip-interface","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/transformer-winding-thermal-trip-interface.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pi26-transformer-relay","publisher":"SEL","title":"SEL-487E transformer protection relay","url":"https://selinc.com/products/487E/","scope":"Transformer protection, monitoring and measurement interfaces.","type":"manufacturer","checkedOn":"2026-11-03","reuse":"link-only","relevance":"Public technical context for transformer protection and monitoring interfaces. Transformer protection, monitoring and measurement interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}