{"schemaVersion":1,"slug":"mechanism-maintenance-alarm-interface","name":"Mechanism maintenance-alarm interface","kind":"symbol","abbreviation":"MMI","aliases":["Stored-energy mechanism supervision","switchgear Stored-energy mechanism supervision","switchgear","Switchgear","Mechanism monitoring output","Maintenance alarm"],"category":"control-circuits","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Brings a documented mechanism maintenance indication into the station alarm system.","description":["Brings a documented mechanism maintenance indication into the station alarm system. A stored-energy breaker mechanism has charging, release, indication and supervision functions. Motor supply, stored spring energy and the ability to complete an opening operation are separate drawing concerns.","In a switchgear panel, a charging motor replenishes the mechanism after an operation. Supervisory contacts let the controller report an incomplete charge or repeated charging demand before an operator requests another operation. For this reference, the drawing identifies “Mechanism monitoring output” at the input and “Maintenance alarm” at the output. An alarm is a maintenance input rather than a diagnosis.","Show the individual contacts and the relevant motor or release circuit. Supply voltage, charging time, operating duty and permissible alarms must follow the chosen mechanism documentation. 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: Mechanism monitoring output. Identify its source device or document and the state represented on the drawing.","Follow the named output: Maintenance alarm. Cross-reference its destination and separate the command from confirmation that the equipment responded.","An alarm is a maintenance input rather than a diagnosis.","Show the individual contacts and the relevant motor or release circuit. Supply voltage, charging time, operating duty and permissible alarms must follow the chosen mechanism documentation."],"drawingChecklist":["Label the source and connection reference for mechanism monitoring output.","Identify the destination and defined state of maintenance alarm.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: An alarm is a maintenance input rather than a diagnosis."],"distinction":"An alarm is a maintenance input rather than a diagnosis. 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":"Switchgear"},{"label":"Input / boundary","value":"Mechanism monitoring output"},{"label":"Output / connection","value":"Maintenance alarm"},{"label":"Lookup label","value":"MMI is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"pi26-masterclad","relevance":"Public technical context for stored-energy mechanism supervision. Breaker control, mechanism, position contacts, racking interlocks and test interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["circuit-breaker","motor","breaker-spring-charging-motor-circuit"],"artwork":"pi26-mechanism-maintenance-alarm-interface","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"switchgear","family":"mechanism","input":"Mechanism monitoring output","output":"Maintenance alarm"},"plainEnglish":{"title":"What this block does","introduction":"Brings a documented mechanism maintenance indication into the station alarm system.","example":"In a switchgear panel, a charging motor replenishes the mechanism after an operation. Supervisory contacts let the controller report an incomplete charge or repeated charging demand before an operator requests another operation. For this reference, the drawing identifies “Mechanism monitoring output” at the input and “Maintenance alarm” at the output. An alarm is a maintenance input rather than a diagnosis.","drawings":"Start at the named input: Mechanism monitoring output. Identify its source device or document and the state represented on the drawing. Follow the named output: Maintenance alarm. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Mechanism monitoring output"},{"name":"Output","meaning":"Maintenance alarm"},{"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":["Mechanism monitoring output","MMI","Maintenance alarm"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"Masterclad medium-voltage switchgear: circuit-breaker section interlocks","url":"https://productinfo.se.com/masterclad_mv_switchgear_ib/6055-30-masterclad-15kv-mv-switchgear-ib/English/6055-30%20Masterclad%20MV%20Switchgear%20Indoor%20%28bookmap%29_DD00646805.xml/%24/Section6-CircuitBreakerSectionInter-58DD6EC7"}],"profileId":"power-installation-mechanism"},"url":"https://eloragrid.ai/symbols/mechanism-maintenance-alarm-interface","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/mechanism-maintenance-alarm-interface.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pi26-masterclad","publisher":"Schneider Electric","title":"Masterclad medium-voltage switchgear: circuit-breaker section interlocks","url":"https://productinfo.se.com/masterclad_mv_switchgear_ib/6055-30-masterclad-15kv-mv-switchgear-ib/English/6055-30%20Masterclad%20MV%20Switchgear%20Indoor%20%28bookmap%29_DD00646805.xml/%24/Section6-CircuitBreakerSectionInter-58DD6EC7","scope":"Breaker control, mechanism, position contacts, racking interlocks and test interfaces.","type":"manufacturer","checkedOn":"2026-11-03","reuse":"link-only","relevance":"Public technical context for stored-energy mechanism supervision. Breaker control, mechanism, position contacts, racking interlocks and test interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}