{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RV1421-0KA10-ZX95","brand":"Siemens","brandSlug":"siemens","productSlug":"3RV1421-0KA10-ZX95","canonicalUrl":"https://aoctrl.com/siemens/3RV1421-0KA10-ZX95","factsUrl":"https://aoctrl.com/api/mcp/products/3RV1421-0KA10-ZX95","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RV1421-0KA10-ZX95, circuit breaker for transformer protection, 1.25 A continuous, 3-pole, Class 10, 100 kA at 400 V AC, screw terminals, IP20, DIN rail mount.","salesMarkdown":"## Transformer Protection Circuit Breaker, 1.25 A, Class 10 The Siemens SIRIUS 3RV1421-0KA10-ZX95 is a 3-pole circuit breaker designed specifically for transformer protection, rated at 1.25 A continuous current with a Class 10 trip characteristic. This means it coordinates with transformer inrush — the magnetic trip element allows the brief high magnetizing current on energization while the thermal bimetal protects against sustained overloads. That figure holds across the full voltage range up to 690 V AC, so this breaker can be placed upstream in a high-fault-current sub-distribution without worrying about cascading failure. Zero clearance needed at the sides or rear — 0 mm backwards and 0 mm at the side — so it packs tight in a crowded enclosure. The IP20 finger-safe front protection means you can reach into the panel without de-energizing the bus for routine visual checks. Main circuit terminals are screw-type, accepting 2x (1... 2.5 mm²) solid or 2x (2.5... 6 mm²) solid, and the same ranges for stranded wire. For AWG, that translates to 2x (14... 10) on the main contacts. The auxiliary and control circuit uses the same screw-terminal style, so you don't need a second tool or separate terminal block for the aux switch wiring. Power dissipation is 7.25 W total in hot operating state, or 2.4 W per pole. That's low enough to skip forced ventilation in a standard IP20 enclosure as long as the ambient stays under 60 °C.","metaTitle":"Siemens 3RV1421-0KA10-ZX95 SIRIUS Circuit Breaker, 1.25 A, C","metaDescription":"Siemens SIRIUS 3RV1421-0KA10-ZX95 circuit breaker for transformer protection. Rated 1.25 A continuous, Class 10 trip, 100 kA breaking capacity at 400 V AC. IP20 front, DIN rail mou","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Protection Circuit Breakers (MPCB)"],"specifications":{"Depth":"96 mm","Solid":"2x (1 ... 2.5 mm²), 2x (2.5 ... 6 mm²)","Width":"45 mm","Height":"97 mm","Stranded":"2x (1 ... 2.5 mm²), 2x (2.5 ... 6 mm²)","Backwards":"0 mm","Trip Class":"CLASS 10","At The Side":"0 mm","Rated Value":"690 V","During Storage":"-50 ... +80 °C","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-50 ... +80 °C","Fastening Method":"screw and snap-on mounting onto 35 mm standard mounting rail according to DIN EN 50022","Shock Resistance":"25g / 11 ms","Mounting Position":"any","Product Brand Name":"SIRIUS","Product Designation":"circuit breaker","Design Of The Product":"for transformer protection","Ground Fault Detection":"No","Phase Failure Detection":"Yes","For Main Current Circuit":"screw-type terminals","at AC at 240 V rated value":"100 kA","at AC at 400 V rated value":"100 kA","at AC at 500 V rated value":"100 kA","at AC at 690 V rated value":"100 kA","at AC-3 rated value maximum":"690 V","at AC in hot operating state":"7.25 W","Substance Prohibitance (Date)":"01.05.2012","Continuous Current Rated Value":"1.25 A","at AWG cables for main contacts":"2x (14 ... 10)","protection class IP on the front":"IP20","For Auxiliary And Control Circuit":"screw-type terminals","Product Extension Auxiliary Switch":"Yes","operating frequency at AC-3 maximum":"15 1/h","Surge Voltage Resistance Rated Value":"6 000 V","at AC in hot operating state per pole":"2.4 W","Finely Stranded With Core End Processing":"2x (1 ... 2.5 mm²), 2x (2.5 ... 6 mm²)","Number Of Poles For Main Current Circuit":"3","Touch Protection Against Electrical Shock":"finger-safe","number of CO contacts for auxiliary contacts":"0","operational current at AC-3 at 400 V rated value":"1.25 A","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Design Of The Overcurrent Release And Short-Circuit Release":"thermomagnetic","Arrangement Of Electrical Connectors For Main Current Circuit":"front side","Product Component Removable Terminal For Auxiliary And Control Circuit":"No","Mechanical Service Life (Switching Cycles) Of The Main Contacts Typical":"100 000","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"0.9 ... 1.25 A"}},"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=221901&mlfb=3RV1421-0KA10-ZX95","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RV1421-0KA10-ZX95/alternatives.json"},"ai":{"faq":[{"question":"What is 3RV1421-0KA10-ZX95's depth?","answer":"The depth is 96 mm, with a width of 45 mm and height of 97 mm."},{"question":"What wire sizes does the 3RV1421-0KA10-ZX95 accept?","answer":"Solid wire: 2x (1... 2.5 mm²) and 2x (2.5... 6 mm²). Stranded: same ranges. AWG main contacts: 2x (14... 10)."},{"question":"What compliance documentation does this SIRIUS breaker carry?","answer":"RoHS compliance date is 01.05.2012. The product is finger-safe (IP20 front) and mounts on DIN rail per DIN EN 50022. Touch protection against electrical shock is finger-safe."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RV1421-0KA10-ZX95","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/3RV1421-0KA10-ZX95 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}}