{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT2637-1NB33","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT2637-1NB33","canonicalUrl":"https://aoctrl.com/siemens/3RT2637-1NB33","factsUrl":"https://aoctrl.com/api/mcp/products/3RT2637-1NB33","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RT2637-1NB33 capacitor contactor, AC-6b 75 kVAr at 400 V, 3-pole, coil 20-33 V AC/DC, integrated varistor, 1 NO + 1 NC auxiliary contacts, screw terminal, size S2.","salesMarkdown":"## Capacitor switching contactor, AC-6b rated The Siemens 3RT2637-1NB33 is a 3-pole capacitor contactor rated for AC-6b duty at 75 kVAr at 400 V. That AC-6b category is the IEC designation for switching capacitor banks — the contactor is designed to handle the high inrush current and repetitive switching of power-factor correction capacitors without welding or excessive wear. The coil accepts 20-33 V AC/DC, 50/60 Hz, with an integrated varistor for surge suppression across the coil terminals. ## Built-in varistor and auxiliary contacts An integrated varistor clamps voltage transients from the coil, which is standard practice for capacitor switching where the coil sees frequent energization. The auxiliary contact block provides 1 NO + 1 NC, wired via screw terminals. Size S2 frame means it occupies a defined DIN-rail footprint consistent with the SIRIUS 3RT2 family — panel layout stays predictable if you're replacing or expanding an existing bank.","metaTitle":"Siemens 3RT2637-1NB33 capacitor contactor, AC-6b 75 kVAr","metaDescription":"Siemens 3RT2637-1NB33 capacitor contactor, AC-6b 75 kVAr at 400 V, 3-pole, coil 20-33 V AC/DC, integrated varistor, 1NO+1NC aux, screw terminal, size S2. Lifecycle current, sourced","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"lifecycle_stage":"current"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/03b9ac415f40bdbc6a31608d15ea8281.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1687158&mlfb=3RT2637-1NB33","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT2637-1NB33/alternatives.json"},"ai":{"faq":[{"question":"What is the 3RT2637-1NB33 used for?","answer":"It is a capacitor contactor for switching power-factor correction capacitor banks under AC-6b duty, rated 75 kVAr at 400 V. The integrated varistor and AC-6b rating make it suitable for the high inrush of capacitor loads."},{"question":"What coil voltage does the 3RT2637-1NB33 accept?","answer":"The coil accepts 20-33 V AC/DC, 50/60 Hz. An integrated varistor protects the coil from voltage transients."},{"question":"Where can I buy the 3RT2637-1NB33?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT2637-1NB33","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/3RT2637-1NB33 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}}