{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RV2421-0FA10","brand":"Siemens","brandSlug":"siemens","productSlug":"3RV2421-0FA10","canonicalUrl":"https://aoctrl.com/siemens/3RV2421-0FA10","factsUrl":"https://aoctrl.com/api/mcp/products/3RV2421-0FA10","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS circuit breaker, 3RV2421-0FA10, Size S0, for transformer protection, 100 kA breaking capacity at 400 V AC, Trip Class 10, screw and snap-on mounting onto 35 mm DIN rail.","salesMarkdown":"It carries a 100 kA breaking capacity at 400 V AC (and at 240 V, 500 V, and 690 V AC as well), so it can interrupt severe faults without upstream fuses needing to clear first. Mounts on a 35 mm DIN rail (DIN EN 60715) with a screw-and-snap-on mechanism — no tools needed for the snap, but the screw terminal connections for the main circuit take an M4 screw and accept 2×(1...2.5 mm²) or 2×(2.5...10 mm²) solid or stranded wire. The S0 frame size keeps the footprint tight at 97 mm deep, 45 mm wide, 97 mm tall, with 50 mm clearance needed above and below for arc venting, and 30 mm at the sides. The 100 kA breaking capacity at 400 V AC (and at 240 V, 500 V, and 690 V AC) means this breaker can safely interrupt a fault current up to 100,000 amps without the arc escaping or the device rupturing — that's high enough for most industrial transformer secondary circuits fed from a large distribution transformer. The gL/gG fuse backup rating at 690 V is 4 A, which tells you the maximum fuse size that can be used upstream for coordination.","metaTitle":"Siemens 3RV2421-0FA10 SIRIUS Circuit Breaker, 100 kA, Size S","metaDescription":"Siemens 3RV2421-0FA10 SIRIUS circuit breaker for transformer protection. 100 kA breaking capacity at 400 V, Trip Class 10, Size S0, screw and snap-on DIN rail mount. Available to o","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":"3RV2421-0FA10","Height":"97 mm","Upwards":"50 mm","Forwards":"0 mm","at 690 V":"gL/gG 4 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 A-release 0.35...0.5 A Short-circuit release 10 A Screw 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 standard mounting rail according to DIN EN 60715","For Main Contacts":"M4","Mounting Position":"any","Solid Or Stranded":"2x (1 ... 2.5 mm²), 2x (2.5 ... 10 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Circuit breaker","at 230 V rated value":"0.1 kW","at 240 V rated value":"100 kA","at 400 V rated value":"100 kA","at 480 V rated value":"0.5 A","at 500 V rated value":"100 kA","at 600 V rated value":"0.5 A","at 690 V rated value":"100 kA","Design Of The Product":"For transformer protection","Ground Fault Detection":"No","Phase Failure Detection":"Yes","For Main Current Circuit":"screw-type terminals","Temperature Compensation":"-20 ... +60 °C","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","Design Of Screwdriver Shaft":"Diameter 5 to 6 mm","Size Of The Circuit-Breaker":"S0","Size Of The Screwdriver Tip":"Pozidriv size 2","at AC-3 rated value maximum":"690 V","Of The Main Contacts Typical":"100 000","at AC in hot operating state":"5.5 W","at AC-3 at 400 V rated value":"0.5 A","Of Auxiliary Contacts Typical":"100 000","Substance Prohibitance (Date)":"10/01/2009","Design Of The Overload Release":"thermal","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"0.5 A","at AWG cables for main contacts":"2x (16 ... 12), 2x (14 ... 8)","Design Of The Short-Circuit Trip":"magnetic","Between Main And Auxiliary Circuit":"400 V","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":"1.8 W","reference code according to IEC 81346-2":"Q","Finely Stranded With Core End Processing":"2x (1 ... 2.5 mm²), 2x (2.5 ... 6 mm²), 1x 10 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","For Main Contacts With Screw-Type Terminals":"2 ... 2.5 N·m","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","Electrical Endurance (Switching 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":"10 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Product Component Removable Terminal For Auxiliary And Control Circuit":"No","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"0.35 ... 0.5 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/d3f8a987cba0dc2bafa9d92608b3e79f.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1135045&mlfb=3RV2421-0FA10"},"ai":{"faq":[{"question":"Where can I buy the 3RV2421-0FA10?","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 closest functional second-source for the 3RV2421-0FA10?","answer":"The 3RV2011-0AA10 is a smaller-frame SIRIUS circuit breaker but it is a general-purpose motor-protective breaker, not a transformer-protection design. It will not drop into the same panel without rewiring because the terminal arrangements and frame size differ. For a direct transformer-protection replacement, stay within the 3RV24 family."},{"question":"Will the 3RV2421-0FA10 drop into a panel specified around the 3RV2011-0AA10?","answer":"No — the 3RV2421-0FA10 uses a Size S0 frame (45 mm wide) while the 3RV2011-0AA10 uses a smaller frame. The mounting hole pattern and terminal layout differ, so rewiring and possibly re-drilling the mounting plate would be required."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RV2421-0FA10","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/3RV2421-0FA10 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}}