{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1935-5AG21","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1935-5AG21","canonicalUrl":"https://aoctrl.com/siemens/3RT1935-5AG21","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1935-5AG21","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS, magnet coil, 3RT1935-5AG21, 110 V AC, 50/60 Hz, for Size S2 contactors, screw terminal.","salesMarkdown":"The Siemens 3RT1935-5AG21 is a SIRIUS-brand magnet coil designed to power the electromagnetic actuator on Size S2 contactors. It's the replacement coil you'd pull when the original burns out or the control voltage changes — not a standalone contactor, just the coil assembly. The coil draws a holding power in the range of 0.8 to 1.1 VA at 50 Hz — that's the steady-state power it pulls once the contactor is sealed in. This is a phased-out product per Siemens. The official successor is the SIRIUS 3RT2 series coil. If you're maintaining a panel that was originally built with this part, you'll want to quote the 3RT1935-5AG21 against an RFQ — we source it through independent distribution channels. ## Deployment context The screw terminal connections match the standard panel wiring practice — spring-cage or screw-clamp depending on the contactor variant. Out here in the grease, if you're swapping a coil on a conveyor starter, make sure the panel power is locked out before you pull the old one; the coil terminals are live whenever the control transformer is hot.","metaTitle":"Siemens 3RT1935-5AG21 SIRIUS Magnet Coil, 110V AC, Size S2","metaDescription":"Siemens SIRIUS 3RT1935-5AG21 magnet coil for Size S2 contactors, 110V AC 50/60Hz. Phased-out product; successor is SIRIUS 3RT2. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"at 50 Hz":"0.8 ... 1.1","lifecycle_stage":"current","Product Brand Name":"SIRIUS","Product Designation":"Magnet coil","at 50 Hz rated value":"110 V","at 60 Hz rated value":"110 V","Type Of Voltage Of The Control Supply Voltage":"AC"}},"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=312679&mlfb=3RT1935-5AG21","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1935-5AG21/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RT1935-5AG21 and how do I get a price?","answer":"This part is sourced and quoted to order against an RFQ. Availability and current pricing are confirmed at quote time through our independent distribution channels."},{"question":"What is 3RT1935-5AG21's rated coil voltage and frequency?","answer":"Rated 110 V AC at both 50 Hz and 60 Hz. The holding power at 50 Hz is in the range of 0.8 to 1.1 VA."},{"question":"What contactor frame size does this coil fit?","answer":"It fits Siemens SIRIUS Size S2 contactors. The coil assembly mounts into the contactor frame with screw terminals for the control wiring."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1935-5AG21","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/3RT1935-5AG21 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}}