{"schemaVersion":1,"slug":"optical-current-measurement-processing-interface","name":"Optical current measurement processing interface","kind":"symbol","abbreviation":"OCMPI","aliases":["Current-transformer secondary arrangements","substations Current-transformer secondary arrangements","substations","Substations","Optical sensing information","Processed current measurement"],"category":"measurement-protection","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Shows the processing boundary between an optical current sensor and its downstream measurement output.","description":["Shows the processing boundary between an optical current sensor and its downstream measurement output. A current-transformer secondary arrangement carries a measuring current from a defined primary location to metering or protection inputs. Core identity, polarity and the connected circuit determine the measurement's meaning.","In a substation protection panel, separate CT cores can supply metering and protection circuits with different duties. A test boundary must preserve the secondary arrangement required by the selected CT and test device. For this reference, the drawing identifies “Optical sensing information” at the input and “Processed current measurement” at the output. Output format depends on the selected sensing system.","Trace every secondary connection and the assigned earthing point against the actual connection diagram. These illustrations explain circuit roles and never prescribe a live CT switching or disconnection procedure. 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: Optical sensing information. Identify its source device or document and the state represented on the drawing.","Follow the named output: Processed current measurement. Cross-reference its destination and separate the command from confirmation that the equipment responded.","Output format depends on the selected sensing system.","Trace every secondary connection and the assigned earthing point against the actual connection diagram. These illustrations explain circuit roles and never prescribe a live CT switching or disconnection procedure."],"drawingChecklist":["Label the source and connection reference for optical sensing information.","Identify the destination and defined state of processed current measurement.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: Output format depends on the selected sensing system."],"distinction":"Output format depends on the selected sensing system. 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":"Optical sensing information"},{"label":"Output / connection","value":"Processed current measurement"},{"label":"Lookup label","value":"OCMPI is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"instrument-transformers","relevance":"Public technical context for current-transformer secondary arrangements. Current and voltage measurement transformers and their secondary interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["current-transformer","ct-test-terminal","protection-core-ct-secondary-circuit"],"artwork":"pi26-optical-current-measurement-processing-interface","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"substations","family":"ct-secondary","input":"Optical sensing information","output":"Processed current measurement"},"plainEnglish":{"title":"What this block does","introduction":"Shows the processing boundary between an optical current sensor and its downstream measurement output.","example":"In a substation protection panel, separate CT cores can supply metering and protection circuits with different duties. A test boundary must preserve the secondary arrangement required by the selected CT and test device. For this reference, the drawing identifies “Optical sensing information” at the input and “Processed current measurement” at the output. Output format depends on the selected sensing system.","drawings":"Start at the named input: Optical sensing information. Identify its source device or document and the state represented on the drawing. Follow the named output: Processed current measurement. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Optical sensing information"},{"name":"Output","meaning":"Processed current measurement"},{"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":["Optical sensing information","OCMPI","Processed current measurement"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"Indoor current and voltage transformers","url":"https://www.abb.com/gb/en/areas/electrification/medium-voltage/grid-components/core-components/indoor-instrument-transformers"}],"profileId":"power-installation-ct-secondary"},"url":"https://eloragrid.ai/symbols/optical-current-measurement-processing-interface","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/optical-current-measurement-processing-interface.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"instrument-transformers","title":"Indoor current and voltage transformers","publisher":"ABB","url":"https://www.abb.com/gb/en/areas/electrification/medium-voltage/grid-components/core-components/indoor-instrument-transformers","type":"manufacturer","scope":"Public current- and voltage-transformer product families. Ratings, terminals and dimensions depend on the model.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public technical context for current-transformer secondary arrangements. Current and voltage measurement transformers and their secondary interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}