{"schemaVersion":1,"slug":"phase-loss-monitoring-relay","name":"Phase-loss monitoring relay","kind":"symbol","abbreviation":"PH LOSS","aliases":["HCR1F42","VCR1F42"],"category":"measurement-protection","drawingTypes":["SLD","Schematic"],"referenceFamilies":["Manufacturer"],"summary":"A phase-loss relay supervises the presence of the specified phases in a three-phase system.","description":["A phase-loss relay supervises the presence of the specified phases in a three-phase system. The drawing identifies the monitored source and output used by control or protection logic."],"readingNotes":["Check whether phase sequence or voltage unbalance is also configured in the selected device.","The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation."],"drawingChecklist":["Show phase measurement inputs","State enabled functions","Reference output logic"],"distinction":"Phase loss is different from phase reversal or current unbalance.","facts":[{"label":"Drawing role","value":"Monitoring element"},{"label":"Representation scope","value":"Functional concept; not an official standard graphic or a product footprint"},{"label":"Public vendor block reference","value":"HCR1F42, VCR1F42 (Autodesk identifiers; not IEC symbol numbers)"},{"label":"Identifier status","value":"The short label is a functional lookup label, not an assigned IEC or IEEE symbol number. Any separately listed Autodesk code is a verified vendor block name."}],"references":[{"sourceId":"pub-symbol-monitoring-relays","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}],"related":["current-transformer","relay-coil"],"artwork":"edu-phase-loss-monitoring-relay","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/phase-loss-monitoring-relay","illustration":{"url":"https://eloragrid.ai/library/illustrations/phase-loss-monitoring-relay.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pub-symbol-monitoring-relays","title":"AutoCAD Electrical: Miscellaneous monitoring relays","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-31F4CF79-F8E0-4E5A-8C51-4D71640ACDB8.htm","type":"cad-reference","scope":"Public vendor catalogue naming and functional variants. Vendor block names are not IEC identifiers. Linked for reference; no graphics or CAD files are redistributed.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}]}