{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3VA9978-0BB16","brand":"Siemens","brandSlug":"siemens","productSlug":"3VA9978-0BB16","canonicalUrl":"https://aoctrl.com/siemens/3VA9978-0BB16","factsUrl":"https://aoctrl.com/api/mcp/products/3VA9978-0BB16","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON accessories, undervoltage release, 250 VDC, 3 slots, 4 kV surge, 690 V rated insulation, 28.8 mm depth.","salesMarkdown":"The Siemens SENTRON 3VA9978-0BB16 is an undervoltage release accessory designed for the 3VA4, 3VA5, and 3VA6 molded-case breaker families. That puts it solidly inside industrial panel environments where transient spikes from motor starts or nearby lightning are a real concern. The 2.5 W DC maximum active power draw tells you the coil dissipation is low enough that it won't cook adjacent components in a crowded enclosure. The 250 VDC operating voltage is specific to the release coil — make sure your control supply matches; this is not a universal AC/DC coil. Three slots (Number of slots = 3) means it occupies three modular width units in the breaker's accessory bay. That's standard for a shunt or undervoltage release in the 3VA platform — no surprises on fit. ## Panel integration Wire stripping length is 10 mm (0.4 in), and the connection accepts AWG18 up to 750 mm² — that's fine for standard control wiring in a panel. The 28.8 mm depth means it sits flush with the breaker body; no extra clearance needed behind the DIN rail.","metaTitle":"3VA9978-0BB16 SENTRON undervoltage release, 250 VDC, 3 slots","metaDescription":"Siemens SENTRON 3VA9978-0BB16 undervoltage release for 3VA4/5/6 breakers. 690 V rated insulation, 4 kV surge, 2.5 W DC. Active lifecycle, sourced 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":"3VA9978-0BB16","Height":"65.1 mm","Accessories":"Auxiliary release","description":"undervoltage release 250V DC accessory for: 3VA4/5/6","Number of slots":"3","Product version":"Auxiliary release","lifecycle_stage":"current","Product brand name":"SENTRON","Degree of pollution":"3","Product designation":"Accessories","Overvoltage category":"III","Wire stripping length":"10 mm","Surge voltage resistance":"4 kV","Wire stripping length [in]":"0.4 in","Rated insulation voltage Ui":"690 V","Type of auxiliary circuit connection":"AWG18 / 750 mm","Consumed active power / at DC / maximum":"2.5 W"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/dc91df574c71d342380e0db5b8e39a89.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=650523&mlfb=3VA9978-0BB16"},"ai":{"faq":[{"question":"What is 3VA9978-0BB16 used for?","answer":"It's an undervoltage release accessory for Siemens SENTRON 3VA4, 3VA5, and 3VA6 molded-case circuit breakers. It trips the breaker when the control voltage drops, preventing automatic restart after a power sag."},{"question":"What compliance documentation does Siemens provide for 3VA9978-0BB16?","answer":"The part carries Overvoltage Category III and Pollution Degree 3 ratings per IEC standards. Specific RoHS, REACH, and UL documentation is available from the manufacturer upon request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3VA9978-0BB16","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/3VA9978-0BB16 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}}