{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1934-5BF42","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1934-5BF42","canonicalUrl":"https://aoctrl.com/siemens/3RT1934-5BF42","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1934-5BF42","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT1934-5BF42, magnet coil for Size S2 contactors, 110 V DC, spring-loaded connection technology.","salesMarkdown":"The Siemens SIRIUS 3RT1934-5BF42 is a replacement magnet coil for Size S2 contactors in the SIRIUS family, wound for 110 V DC control voltage and terminated with spring-loaded (cage-clamp) connections. Size S2 covers contactors rated for motor currents roughly in the 38–65 A AC-3 range at 400 V — think medium conveyors, pump starters, compressor duty. The coil itself is the replaceable electromagnet that pulls the contactor in; when a coil fails open or shorts, you swap this rather than the whole contactor assembly. ## Lifecycle reality — phased out, successor known If you are designing a new panel or have the flexibility to change the contactor base, the 3RT2 series is the official forward path. ## What the 110 V DC rating means for the panel The 110 V DC control supply is common in North American industrial control panels with DC control buses, and in some European process plants that run 110 V DC for reliability over long cable runs. Because this is a DC coil, the holding power is continuous; there is no AC hum or shading ring to fail. Verify your DC supply can deliver the inrush without droop — a 110 V DC coil pulling in can dip a marginal power supply below the dropout threshold of other devices on the same bus.","metaTitle":"Siemens SIRIUS 3RT1934-5BF42 Magnet Coil, 110 V DC, Size S2","metaDescription":"Siemens SIRIUS 3RT1934-5BF42 magnet coil for Size S2 contactors, 110 V DC, spring-loaded terminals. Phased-out product with successor 3RT2 series. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"lifecycle_stage":"current","Product Brand Name":"SIRIUS","1 at DC rated value":"110 V","Product Designation":"Magnet coil","Type Of Voltage Of The Control Supply Voltage":"DC"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=189174&mlfb=3RT1934-5BF42","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1934-5BF42/alternatives.json"},"ai":{"faq":[{"question":"What is the closest functional second-source — 3RT1015-1BB42?","answer":"3RT1015-1BB42 is a Size S00 power contactor with a 24 V DC coil and screw terminals — different frame size, different voltage, different termination. It is not a functional substitute for the Size S2 110 V DC coil. The correct replacement path is the 3RT2 series contactor that matches your load current and control voltage."},{"question":"Will 3RT1934-5BF42 drop into a panel specified around 3RT1015-1BB42 without rewiring?","answer":"No. 3RT1015-1BB42 is a complete Size S00 contactor (45 mm wide, screw terminals, 24 V DC coil). 3RT1934-5BF42 is a replacement coil for a Size S2 contactor (70 mm wide frame, spring-loaded terminals, 110 V DC). The mounting rail position, wiring, and control voltage are all different."},{"question":"What is the lifecycle stage of 3RT1934-5BF42?","answer":"The lifecycle stage is listed as 'current' in the spec field, but the product description explicitly states 'Phased-out product!!!' with a successor identified. This means it is at end of commercial availability — not recommended for new designs."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1934-5BF42","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/3RT1934-5BF42 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}