{"schemaVersion":1,"slug":"microgrid-synchronising-close-permissive-block","name":"Microgrid synchronising close-permissive block","kind":"symbol","abbreviation":"MSCB","aliases":["Microgrid synchronising interfaces","microgrids Microgrid synchronising interfaces","microgrids","Microgrids","Synchronising checks","PCC close permission"],"category":"microgrid-systems","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Combines the specified synchronising conditions into the assigned breaker-closing permission.","description":["Combines the specified synchronising conditions into the assigned breaker-closing permission. Synchronising control compares two AC systems before their assigned connecting breaker closes. Voltage magnitude, frequency, phase relationship, breaker readiness and command authority are separate inputs to the closing decision.","In a microgrid reconnecting at its point of common coupling, a synchroniser can adjust the island reference while a separate permissive confirms the permitted relationship across the open breaker. For this reference, the drawing identifies “Synchronising checks” at the input and “PCC close permission” at the output. The permissive is not the final coil output.","Identify the two measurement sides and the equipment receiving any adjustment request. Closing limits, breaker timing and loss-of-measurement behavior require the approved synchronising design. 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: Synchronising checks. Identify its source device or document and the state represented on the drawing.","Follow the named output: PCC close permission. Cross-reference its destination and separate the command from confirmation that the equipment responded.","The permissive is not the final coil output.","Identify the two measurement sides and the equipment receiving any adjustment request. Closing limits, breaker timing and loss-of-measurement behavior require the approved synchronising design."],"drawingChecklist":["Label the source and connection reference for synchronising checks.","Identify the destination and defined state of pcc close permission.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: The permissive is not the final coil output."],"distinction":"The permissive is not the final coil output. 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":"Microgrids"},{"label":"Input / boundary","value":"Synchronising checks"},{"label":"Output / connection","value":"PCC close permission"},{"label":"Lookup label","value":"MSCB is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"pi26-mg-design","relevance":"Public technical context for microgrid synchronising interfaces. Microgrid power and control interfaces, synchronisation and source coordination. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["25-synchronism-check","synchronoscope","microgrid-breaker-closing-time-compensation"],"artwork":"pi26-microgrid-synchronising-close-permissive-block","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"microgrids","family":"microgrid-sync","input":"Synchronising checks","output":"PCC close permission"},"plainEnglish":{"title":"What this block does","introduction":"Combines the specified synchronising conditions into the assigned breaker-closing permission.","example":"In a microgrid reconnecting at its point of common coupling, a synchroniser can adjust the island reference while a separate permissive confirms the permitted relationship across the open breaker. For this reference, the drawing identifies “Synchronising checks” at the input and “PCC close permission” at the output. The permissive is not the final coil output.","drawings":"Start at the named input: Synchronising checks. Identify its source device or document and the state represented on the drawing. Follow the named output: PCC close permission. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Synchronising checks"},{"name":"Output","meaning":"PCC close permission"},{"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":["Synchronising checks","MSCB","PCC close permission"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"Microgrid Flex components and control design","url":"https://productinfo.se.com/microgrid_guide/0100db2503_ecostruxure-microgrid-flex_design-guide_iec/English/0100DB2503-Microgrid%20Flex%20Design%20Guide-IEC-Optimize%20%28bookmap%29_DD00654397.XML.xml/%24/MicrogridFlexComponents-3A7DD96C"}],"profileId":"power-installation-microgrid-sync"},"url":"https://eloragrid.ai/symbols/microgrid-synchronising-close-permissive-block","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/microgrid-synchronising-close-permissive-block.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pi26-mg-design","publisher":"Schneider Electric","title":"Microgrid Flex components and control design","url":"https://productinfo.se.com/microgrid_guide/0100db2503_ecostruxure-microgrid-flex_design-guide_iec/English/0100DB2503-Microgrid%20Flex%20Design%20Guide-IEC-Optimize%20%28bookmap%29_DD00654397.XML.xml/%24/MicrogridFlexComponents-3A7DD96C","scope":"Microgrid power and control interfaces, synchronisation and source coordination.","type":"manufacturer","checkedOn":"2026-11-03","reuse":"link-only","relevance":"Public technical context for microgrid synchronising interfaces. Microgrid power and control interfaces, synchronisation and source coordination. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}