{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RV2421-4BA10-ZX95","brand":"Siemens","brandSlug":"siemens","productSlug":"3RV2421-4BA10-ZX95","canonicalUrl":"https://aoctrl.com/siemens/3RV2421-4BA10-ZX95","factsUrl":"https://aoctrl.com/api/mcp/products/3RV2421-4BA10-ZX95","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS circuit breaker for transformer protection, 3RV2421-4BA10-ZX95, CLASS 10 trip, 25 kA breaking capacity at 400 V, 45 mm wide, screw and snap-on DIN-rail mount.","salesMarkdown":"## Transformer-protection breaker with 25 kA interrupting capacity That distinction matters: the trip curve and short-circuit ratings are tuned for inrush-heavy transformer loads rather than motor starting profiles. The 25 kA at 400 V is the SCCR (short-circuit current rating) that governs whether this breaker coordinates with upstream protective devices in a panel. If your transformer secondary fault current exceeds 25 kA at 400 V, this breaker won't safely interrupt — you'd need a higher-rated device or current-limiting fuses ahead of it. At 240 V the rating jumps to 100 kA, so on 240 V secondaries it's very robust. The gL/gG fuse coordination values (63 A at 400 V, 50 A at 500 V and 690 V) tell you the maximum upstream fuse that still allows the breaker to clear a fault without the fuse blowing first — critical for selective coordination studies. The 45 mm width means it takes one standard 45 mm module slot — no surprise when panel-building. Terminal screws are M4 for the main contacts, accepting 2x (1 to 2.5 mm²) or 2x (2.5 to 10 mm²) solid or stranded copper. Clearance requirements: 50 mm upwards and downwards, 30 mm at the sides, 0 mm forwards and backwards — tight on the backplane, but leave breathing room above and below for arc quenching.","metaTitle":"Siemens 3RV2421-4BA10-ZX95 SIRIUS Circuit Breaker, 25 kA at","metaDescription":"Siemens 3RV2421-4BA10-ZX95 SIRIUS circuit breaker for transformer protection. CLASS 10 trip, 25 kA at 400 V, 100 kA at 240 V. DIN-rail mount, phase failure detection. Sourced to or","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":"3RV2421-4BA10-ZX95","Height":"97 mm","Upwards":"50 mm","Forwards":"0 mm","at 400 V":"gL/gG 63 A","at 500 V":"gL/gG 50 A","at 690 V":"gL/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 SZ S0, FOR TRANSFORMER PROT. A-RELEASE 13...20A, N-RELEASE 325A, SCREW CONNECTION, STANDARD SW. 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","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":"3 hp","at 240 V rated value":"100 kA","at 400 V rated value":"25 kA","at 480 V rated value":"20 A","at 500 V rated value":"5 kA","at 600 V rated value":"20 A","at 690 V rated value":"2 kA","Design Of The Product":"For transformer protection","Ground Fault Detection":"No","Phase Failure Detection":"Yes","For Main Current Circuit":"screw-type terminals","at 110/120 V rated value":"1.5 hp","at 200/208 V rated value":"7.5 hp","at 220/230 V rated value":"5 hp","at 460/480 V rated value":"10 hp","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 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":"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","for AWG cables for main contacts":"2x (16 ... 12), 2x (14 ... 8)","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 ... 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 (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/226b2996537df4fe714581908e8b8416.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=1091497&mlfb=3RV2421-4BA10-ZX95"},"ai":{"faq":[{"question":"What is the breaking capacity of 3RV2421-4BA10-ZX95 at 400 V?","answer":"25 kA at 400 V, with 100 kA at 240 V and 5 kA at 500 V. The 400 V rating is the one that governs most industrial panel coordination studies."},{"question":"Will 3RV2421-4BA10-ZX95 drop into a panel specified for 3RV2023-4DA10?","answer":"Both are 45 mm wide SIRIUS breakers on the same DIN-rail footprint, so mechanical fit is the same. However, 3RV2421-4BA10-ZX95 is designed for transformer protection while the 3RV2023-4DA10 is a motor-protection variant — the trip curves differ. Verify the coordination study before swapping; the physical swap is fine, the protection coordination may not be."},{"question":"Where can I buy 3RV2421-4BA10-ZX95 and how is it quoted?","answer":"Sourced through independent industrial-automation distribution. Quoted to order against an RFQ — availability and current pricing are confirmed at quote time, not on a public listing."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RV2421-4BA10-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/3RV2421-4BA10-ZX95 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}}