{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3VA9978-0BB10","brand":"Siemens","brandSlug":"siemens","productSlug":"3VA9978-0BB10","canonicalUrl":"https://aoctrl.com/siemens/3VA9978-0BB10","factsUrl":"https://aoctrl.com/api/mcp/products/3VA9978-0BB10","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SENTRON 3VA9978-0BB10 undervoltage release, 12V DC, 2.5 W, 4 kV surge, Pollution Degree 3, for 3VA4/5/6 breakers.","salesMarkdown":"The Siemens SENTRON 3VA9978-0BB10 is a 12V DC undervoltage release designed as an auxiliary release for the 3VA4, 3VA5, and 3VA6 molded-case circuit breaker families. Rated for 12V DC at 2.5 W maximum power consumption, so it's a straight DC coil — no AC rectifier inside. That 2.5 W is the holding power once the coil is energized; inrush is higher for the pickup transient, so size your control transformer or DC supply accordingly. ## Panel integration This release snaps into the 3VA breaker's accessory slot — three slots are available on the breaker, and this occupies one. The body measures 28.8 mm deep by 25.7 mm wide by 65.1 mm tall, so it stays within the breaker's own envelope; no extra DIN-rail space needed. Wiring is via screw terminals accepting AWG 18 or up to 750 mm² (likely a typo for 0.75 mm² or 1.5 mm² — strip 10 mm / 0.4 in).","metaTitle":"Siemens 3VA9978-0BB10 SENTRON Undervoltage Release, 12V DC","metaDescription":"Siemens SENTRON 3VA9978-0BB10 undervoltage release for 3VA4/5/6 breakers. 12V DC, 2.5W, 4kV surge, Pollution Degree 3. Active production, 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":"3VA9978-0BB10","Height":"65.1 mm","Accessories":"Auxiliary release","description":"undervoltage release 12V 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/dc7b2e9d8b9e1c101a98cdc41eb2002d.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=650519&mlfb=3VA9978-0BB10"},"ai":{"faq":[{"question":"What is 3VA9978-0BB10 used for?","answer":"It's a 12V DC undervoltage release that fits the Siemens SENTRON 3VA4, 3VA5, and 3VA6 molded-case circuit breakers. It trips the breaker when control voltage drops below the release's dropout threshold, commonly used in motor control centers and safety isolation circuits."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3VA9978-0BB10","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/3VA9978-0BB10 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}}