{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RV2421-4BA20-0DA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RV2421-4BA20-0DA0","canonicalUrl":"https://aoctrl.com/siemens/3RV2421-4BA20-0DA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RV2421-4BA20-0DA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RV2421-4BA20-0DA0, circuit breaker for transformer protection, Size S0, Trip Class 10, 25 kA at 400 V, 100 kA at 240 V, screw and snap-on mounting onto 35 mm DIN rail.","salesMarkdown":"## Transformer-protection circuit breaker, SIRIUS size S0 The breaker is rated for a 5.5 kW transformer at 230 V and carries a 25 kA interrupting capacity at 400 V (55 kA AC at 400 V), with a maximum 100 kA at 240 V. It mounts on a 35 mm DIN rail per DIN EN 60715, using either screw or snap-on fastening, and accepts spring-loaded terminals for the main circuit — 2× (1 to 10 mm²) solid or stranded. The breaker occupies the S0 frame size: 45 mm wide, 119 mm tall, 97 mm deep. Clearance requirements: 50 mm upward, 50 mm downward, 30 mm to the side, zero forward or backward. These are the minimum free-air gaps for arc quenching and thermal dissipation — a panel builder must respect them, not just the DIN-rail footprint. ## Interrupting capacity and back-up fuse coordination The interrupting capacity varies by voltage: 100 kA at 240 V (AC), 55 kA at 400 V (AC), 10 kA at 500 V (AC), 4 kA at 690 V (AC). For installations where the prospective fault current exceeds these values, the breaker must be backed by upstream gG fuses: 63 A at 400 V, 50 A at 500 V, 50 A at 690 V. The maximum switching frequency is 15 operations per hour for AC-3 and AC-3e duty — this is a protection device, not a switching contactor; repeated cycling above that rate will degrade the thermal bimetal calibration.","metaTitle":"Siemens SIRIUS 3RV2421-4BA20-0DA0 Circuit Breaker, Transform","metaDescription":"Siemens SIRIUS 3RV2421-4BA20-0DA0 circuit breaker for transformer protection. Trip Class 10, 25 kA at 400 V, 100 kA at 240 V. Size S0, DIN rail mount. Current production. Available","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Protection Circuit Breakers (MPCB)"],"specifications":{"Depth":"97 mm","Width":"45 mm","title":"3RV2421-4BA20-0DA0","Height":"119 mm","Upwards":"50 mm","Forwards":"0 mm","at 400 V":"gG 63 A","at 500 V":"gG 50 A","at 690 V":"gG 50 A","Backwards":"0 mm","Downwards":"50 mm","Trip Class":"CLASS 10","At The Side":"30 mm","Rated Value":"20 ... 690 V","description":"circuit breaker size S0 for transformer protection without phase failure protection A-release 13...20 A short-circuit release 325 A spring-loaded terminal standard switching capacity","During Storage":"-50 ... +80 °C","at AC-3 maximum":"15 1/h","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-50 ... +80 °C","Fastening Method":"screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715","at AC-3e maximum":"15 1/h","Mounting Position":"any","Solid Or Stranded":"2x (1 ... 10 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Circuit breaker","at 230 V rated value":"5.5 kW","at 240 V rated value":"100 kA","at 400 V rated value":"25 kA","at 500 V rated value":"5 kA","at 690 V rated value":"2 kA","Design Of The Product":"For transformer protection","Ground Fault Detection":"No","Phase Failure Detection":"No","For Main Current Circuit":"spring-loaded terminals","at AC at 240 V rated value":"100 kA","at AC at 400 V rated value":"55 kA","at AC at 500 V rated value":"10 kA","at AC at 690 V rated value":"4 kA","Design Of Screwdriver Shaft":"Diameter 3 mm","Size Of The Circuit-Breaker":"S0","Size Of The Screwdriver Tip":"3,0 x 0,5 mm","at AC-3 rated value maximum":"690 V","Of The Main Contacts Typical":"100 000","at AC in hot operating state":"10.5 W","at AC-3 at 400 V rated value":"20 A","at AC-3e rated value maximum":"690 V","Of Auxiliary Contacts Typical":"100 000","Substance Prohibitance (Date)":"10/01/2009","at AC-3e at 400 V rated value":"20 A","Design Of The Overload Release":"thermal","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"20 A","Design Of The Short-Circuit Trip":"magnetic","Product Extension Auxiliary Switch":"Yes","Relative Humidity During Operation":"10 ... 95 %","Display Version For Switching Status":"Handle","Surge Voltage Resistance Rated Value":"6 kV","at AC in hot operating state per pole":"3.5 W","With Side-By-Side Mounting At The Side":"0 mm","reference code according to IEC 81346-2":"Q","Finely Stranded With Core End Processing":"2x (1 ... 6 mm²)","Number Of Poles For Main Current Circuit":"3","Product Function Short Circuit Protection":"Yes","with low demand rate according to SN 31920":"50 FIT","Finely Stranded Without Core End Processing":"2x (1 ... 6 mm²)","with high demand rate according to SN 31920":"50 %","number of CO contacts for auxiliary contacts":"0","number of NC contacts for auxiliary contacts":"0","number of NO contacts for auxiliary contacts":"0","shock resistance according to IEC 60068-2-27":"25g / 11 ms Sinus","Electrical Endurance (Operating Cycles) Typical":"100 000","Size Of Contactor Can Be Combined Company-Specific":"S00, S0","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Arrangement Of Electrical Connectors For Main Current Circuit":"Top and bottom","Response Value Current Of Instantaneous Short-Circuit Trip Unit":"325 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"13 ... 20 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/3a27fb79cce814e00c50ecc81daca6c9.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1497494&mlfb=3RV2421-4BA20-0DA0"},"ai":{"faq":[{"question":"Where can I buy 3RV2421-4BA20-0DA0 and get a price?","answer":"This part is sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time."},{"question":"What is the depth of 3RV2421-4BA20-0DA0?","answer":"The depth is 97 mm."},{"question":"What is the width of 3RV2421-4BA20-0DA0?","answer":"The width is 45 mm."},{"question":"What compliance documentation is available for this breaker?","answer":"The evidence does not list specific compliance documents (RoHS, REACH, UL, IEC) for this order code. The product is a Siemens SIRIUS circuit breaker, which typically carries IEC/EN 60947-2 certification and CE marking as standard for the series, but confirm the exact documentation package with your order."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RV2421-4BA20-0DA0","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/3RV2421-4BA20-0DA0 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:51:03.652Z","lastPublished":"2026-08-11T15:51:03.652Z","indexable":true}}