{"schemaVersion":1,"slug":"32u-underpower-protection","name":"Underpower protection","kind":"function","abbreviation":"32U","aliases":["low active power","active underpower","DUPPDPR","ANSI 32U","IEEE 32U"],"category":"measurement-protection","drawingTypes":["SLD","Schematic"],"referenceFamilies":["IEEE / ANSI","Manufacturer"],"summary":"Supervises active power below the documented operating criterion.","description":["Supervises active power below the documented operating criterion.","The drafting record should connect this function to the active-power measurement circuit and operating-state supervision, then trace the underpower alarm or selected protection output. 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 active-power measurement circuit and operating-state supervision.","Trace the underpower alarm or selected protection output."],"drawingChecklist":["Label the active-power measurement circuit and operating-state supervision.","Cross-reference the underpower alarm or selected protection output.","Retain the complete suffix, selected device tag and manufacturer manual revision."],"distinction":"An underpower element measures power; undercurrent 37 can respond differently when voltage or power factor changes.","facts":[{"label":"Function designation","value":"32U"},{"label":"Base function","value":"32 — Directional power"},{"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":["32-directional-power","current-transformer"],"artwork":"pub-function-box","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/protection-functions/32u-underpower-protection","illustration":{"url":"https://eloragrid.ai/library/illustrations/32u-underpower-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."}]}