{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3VA9978-0BB11","brand":"Siemens","brandSlug":"siemens","productSlug":"3VA9978-0BB11","canonicalUrl":"https://aoctrl.com/siemens/3VA9978-0BB11","factsUrl":"https://aoctrl.com/api/mcp/products/3VA9978-0BB11","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 3VA9978-0BB11 undervoltage release, 24V DC, for 3VA4/5/6 molded-case circuit breakers, 3 slots, 2.5 W max DC consumption.","salesMarkdown":"The Siemens SENTRON 3VA9978-0BB11 is an undervoltage release accessory for the 3VA4, 3VA5, and 3VA6 series of molded-case circuit breakers. The release draws 2.5 W maximum at DC — negligible for the control transformer budget, but verify your 24 V DC supply can handle the inrush when multiple releases trip simultaneously. Dimensions are 25.7 mm wide, 65.1 mm high, and 28.8 mm deep — it mounts inside the breaker's accessory bay, not on the DIN rail, so no additional panel width is consumed. Wire connection for the auxiliary circuit accepts AWG 18 up to 750 mm length; strip 10 mm (0.4 in) for a secure termination.","metaTitle":"Siemens SENTRON 3VA9978-0BB11 Undervoltage Release, 24V DC","metaDescription":"Siemens SENTRON 3VA9978-0BB11 undervoltage release, 24V DC, for 3VA4/5/6 breakers. Active production. Rated surge 4 kV, pollution degree 3. Available to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Breaker Accessories"],"specifications":{"Depth":"28.8 mm","Width":"25.7 mm","title":"3VA9978-0BB11","Height":"65.1 mm","Accessories":"Auxiliary release","description":"undervoltage release 24V DC accessory for: 3VA4/5/6","Number Of Slots":"3","Stripped Length":"10 mm","lifecycle_stage":"current","Product Brand Name":"SENTRON","Degree Of Pollution":"3","Product Designation":"Accessories","Overvoltage Category":"III","Stripped Length [In]":"0.4 in","Design Of The Product":"Auxiliary release","Surge Voltage Resistance":"4 kV","consumed active power / at DC / maximum":"2.5 W","Type Of Electrical Connection / For Auxiliary Circuit":"AWG18 / 750 mm"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/9ef77c2f37888b97a9e6d284b6510a80.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=650520&mlfb=3VA9978-0BB11"},"ai":{"faq":[{"question":"What is 3VA9978-0BB11 used for?","answer":"It is an undervoltage release for Siemens SENTRON 3VA4, 3VA5, and 3VA6 molded-case circuit breakers — it trips the breaker when the control voltage drops below the dropout threshold, protecting downstream equipment from brownout or phase-loss conditions."},{"question":"Will 3VA9978-0BB11 drop into a panel specified around 5SY4140-7?","answer":"No — the 5SY4140-7 is a miniature circuit breaker, not a 3VA series MCCB. The 3VA9978-0BB11 is an internal accessory for the 3VA4/5/6 breaker family and does not fit the 5SY platform."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3VA9978-0BB11","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/siemens/3VA9978-0BB11 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}