{"schemaVersion":1,"slug":"49m-motor-thermal-model-protection","name":"Motor thermal-model protection","kind":"function","abbreviation":"49M","aliases":["motor thermal overload","MPTTR","ANSI 49M","IEEE 49M"],"category":"measurement-protection","drawingTypes":["SLD","Schematic"],"referenceFamilies":["IEEE / ANSI","Manufacturer"],"summary":"Estimates motor thermal duty using the selected relay's motor thermal model.","description":["Estimates motor thermal duty using the selected relay's motor thermal model.","The drafting record should connect this function to the motor current measurements and thermal-model data reference, then trace the thermal overload trip and restart permission. Keep the complete designation and equipment tag together so that the SLD, relay logic and terminal schedule describe the same implementation.","The cited mapping is a public manufacturer example (ABB Relion 620 function mapping). Suffixes are not universal equivalences across products, and this reference supplies neither a protection setting nor certification of the selected scheme."],"readingNotes":["Identify the motor current measurements and thermal-model data reference.","Trace the thermal overload trip and restart permission."],"drawingChecklist":["Label the motor current measurements and thermal-model data reference.","Cross-reference the thermal overload trip and restart permission.","Retain the complete suffix, selected device tag and manufacturer manual revision."],"distinction":"A motor thermal model is distinct from a winding thermostat or an RTD alarm channel; both can coexist.","facts":[{"label":"Function designation","value":"49M"},{"label":"Base function","value":"49 — Thermal protection"},{"label":"Published mapping","value":"ABB Relion 620 function mapping"},{"label":"Suffix scope","value":"Application or manufacturer specific; check the complete drawing legend and selected device manual."}],"references":[{"sourceId":"pub-function-abb-mappings","relevance":"Public primary-source function or application mapping used to identify this designation; wording and drafting notes are original."},{"sourceId":"ieee-functions","relevance":"Device-number and suffix convention. This page is not a reproduction of the full licensed standard."}],"related":["49-thermal-protection","current-transformer"],"artwork":"pub-function-box","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/protection-functions/49m-motor-thermal-model-protection","illustration":{"url":"https://eloragrid.ai/library/illustrations/49m-motor-thermal-model-protection.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pub-function-abb-mappings","title":"Relion 620 series: published protection function and designation mappings","publisher":"ABB","url":"https://techdoc.relays.protection-control.abb/r/620-series-IEC-60870-5-103-Point-List-Manual/2.0-FP1-IEC/en-US/Functions-codes-and-symbols","type":"manufacturer","scope":"Manufacturer mapping of function names, IEC identifiers and ANSI labels. These are examples for a documented product family, not universal equivalences between standards or products.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public primary-source function or application mapping used to identify this designation; wording and drafting notes are original."},{"id":"ieee-functions","title":"IEEE C37.2-2022: power-system device function numbers","publisher":"IEEE","url":"https://ieeexplore.ieee.org/document/9984140","type":"standard","scope":"Device function numbers, acronyms and contact designations. The full publication may require access through IEEE.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Device-number and suffix convention. This page is not a reproduction of the full licensed standard."}]}