{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1934-5BG42","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1934-5BG42","canonicalUrl":"https://aoctrl.com/siemens/3RT1934-5BG42","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1934-5BG42","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS, magnet coil for Size S2 contactors, 3RT1934-5BG42, 125 V DC, spring-loaded connection technology.","salesMarkdown":"The Siemens 3RT1934-5BG42 is a SIRIUS magnet coil designed for Size S2 contactors. It operates on a 125 V DC control supply voltage and terminates via spring-loaded connections — a push-in style that eliminates screw torqueing and speeds up panel wiring. This coil is a phased-out product. The manufacturer lists the successor as the SIRIUS 3RT2 series. No official cross-reference to a direct drop-in replacement is provided beyond the series-level successor. ## What the 125 V DC rating means for fit The 125 V DC coil voltage is the key fit parameter. If your existing panel supplies 125 V DC control power — common in North American industrial installations with battery-backed DC buses — this coil pulls in and holds the contactor without a dropping resistor or separate DC-DC converter.","metaTitle":"Siemens 3RT1934-5BG42 SIRIUS Magnet Coil, 125 V DC, Size S2","metaDescription":"Siemens SIRIUS 3RT1934-5BG42 magnet coil for Size S2 contactors. 125 V DC, spring-loaded terminals. Phased-out; successor is SIRIUS 3RT2 series. Sourced to order against RFQ.","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":"125 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=126721&mlfb=3RT1934-5BG42","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1934-5BG42/alternatives.json"},"ai":{"faq":[{"question":"What replaces 3RT1934-5BG42?","answer":"The official successor is the SIRIUS 3RT2 series. A direct order-code cross-reference is not provided; the replacement must be selected based on Size S2 contactor frame and 125 V DC coil voltage."},{"question":"How do I source this part?","answer":"As a phased-out product, 3RT1934-5BG42 is sourced through surplus or independent distributor channels. Submit an RFQ for current availability and pricing."},{"question":"What brand and series is this coil from?","answer":"It is a Siemens SIRIUS magnet coil, Size S2, with spring-loaded connection technology."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1934-5BG42","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/3RT1934-5BG42 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}}