{"schemaVersion":1,"slug":"vt-measurement-ratio-scaling-block","name":"VT measurement ratio scaling block","kind":"symbol","abbreviation":"VMRSB","aliases":["Voltage-transformer secondary arrangements","substations Voltage-transformer secondary arrangements","substations","Substations","Measured voltage and ratio","Primary-basis voltage quantity"],"category":"measurement-protection","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Scales the secondary measurement to the assigned primary-voltage basis.","description":["Scales the secondary measurement to the assigned primary-voltage basis. A voltage-transformer secondary arrangement connects a defined primary voltage measurement to protection, metering or control inputs. Winding identity, fuse protection and the voltage reference must remain visible across the drawing.","In a substation bay, one voltage circuit can feed protection while a separately identified winding supplies metering. A voltage-selection circuit must make clear which bus or line measurement is being used. For this reference, the drawing identifies “Measured voltage and ratio” at the input and “Primary-basis voltage quantity” at the output. Scaling does not correct a wiring error.","Show the primary measurement point, secondary connection, protective devices and relay reference. A missing measurement can resemble a real system disturbance unless the voltage-circuit health is supervised appropriately. 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: Measured voltage and ratio. Identify its source device or document and the state represented on the drawing.","Follow the named output: Primary-basis voltage quantity. Cross-reference its destination and separate the command from confirmation that the equipment responded.","Scaling does not correct a wiring error.","Show the primary measurement point, secondary connection, protective devices and relay reference. A missing measurement can resemble a real system disturbance unless the voltage-circuit health is supervised appropriately."],"drawingChecklist":["Label the source and connection reference for measured voltage and ratio.","Identify the destination and defined state of primary-basis voltage quantity.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: Scaling does not correct a wiring error."],"distinction":"Scaling does not correct a wiring error. 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":"Measured voltage and ratio"},{"label":"Output / connection","value":"Primary-basis voltage quantity"},{"label":"Lookup label","value":"VMRSB is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"instrument-transformers","relevance":"Public technical context for voltage-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":["voltage-transformer","potential-test-switch","vt-secondary-star-point-identification"],"artwork":"pi26-vt-measurement-ratio-scaling-block","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"substations","family":"vt-secondary","input":"Measured voltage and ratio","output":"Primary-basis voltage quantity"},"plainEnglish":{"title":"What this block does","introduction":"Scales the secondary measurement to the assigned primary-voltage basis.","example":"In a substation bay, one voltage circuit can feed protection while a separately identified winding supplies metering. A voltage-selection circuit must make clear which bus or line measurement is being used. For this reference, the drawing identifies “Measured voltage and ratio” at the input and “Primary-basis voltage quantity” at the output. Scaling does not correct a wiring error.","drawings":"Start at the named input: Measured voltage and ratio. Identify its source device or document and the state represented on the drawing. Follow the named output: Primary-basis voltage quantity. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Measured voltage and ratio"},{"name":"Output","meaning":"Primary-basis voltage quantity"},{"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":["Measured voltage and ratio","VMRSB","Primary-basis voltage quantity"],"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-vt-secondary"},"url":"https://eloragrid.ai/symbols/vt-measurement-ratio-scaling-block","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/vt-measurement-ratio-scaling-block.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 voltage-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."}]}