{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RV2321-4AC20-0BA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RV2321-4AC20-0BA0","canonicalUrl":"https://aoctrl.com/siemens/3RV2321-4AC20-0BA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RV2321-4AC20-0BA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS S0 circuit breaker for starter combinations, 3RV2321-4AC20-0BA0, 55 kA breaking capacity at 400 V AC, screw and snap-on 35 mm DIN rail.","salesMarkdown":"The Siemens 3RV2321-4AC20-0BA0 is a SIRIUS S0 frame circuit breaker built for starter combinations — the kind of box that sits between a contactor and a motor in a crusher drive or conveyor panel. It screws or snaps onto a 35 mm DIN rail per DIN EN 60715, and the spring-loaded terminals on the main circuit accept 2x 1–10 mm² solid or stranded copper. That terminal pitch and the 45 mm width mean it rows up cleanly with a SIRIUS contactor on the same rail without adapters. ## Rated breaking capacity — the number that matters for fault coordination At 400 V AC this breaker clears 55 kA — that is the SCCR the panel label will carry, and it is enough to sit behind a 630 kVA transformer feeding a mill motor center. At 240 V AC it holds 100 kA, at 500 V AC 10 kA, and at 690 V AC 4 kA. The backup fuse limits are tighter: a gG 63 A fuse at 400 V, gG 50 A at 500 V, gG 40 A at 690 V. If you are coordinating with upstream fuses, those are the numbers the selectivity study will use, not the breaker's own interrupting rating. ## Clearances and panel layout The body is 97 mm deep, 45 mm wide, 119 mm tall. That zero-forward spec is unusual for an S0 frame; most need some breathing room for arc chute venting. This one does not, which simplifies layout in a tight enclosure.","metaTitle":"Siemens 3RV2321-4AC20-0BA0 SIRIUS Motor Circuit Breaker, 55","metaDescription":"Siemens 3RV2321-4AC20-0BA0 SIRIUS motor circuit breaker for starter combinations. Rated 55 kA SCCR at 400 V AC. Screw and snap-on 35 mm DIN rail. Active production. Sourced to orde","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":"3RV2321-4AC20-0BA0","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 40 A","Backwards":"0 mm","Downwards":"50 mm","At The Side":"30 mm","Rated Value":"20 ... 690 V","description":"Special type Circuit breaker size S0 for starter combination rated current 16 A N-release 208 A Spring-type terminal Standard switching capacity Ambient temperature -50 °C 500 switching cycles","During Storage":"-50 ... +80 °C","at AC-3 maximum":"15 1/h","lifecycle_stage":"current","During Operation":"-50 ... +60 °C","During Transport":"-50 ... +80 °C","Fastening Method":"screw and snap-on mounting onto 35 mm DIN rail according to DIN EN 60715","Mounting Position":"any","Solid Or Stranded":"2x (1 ... 10 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Circuit breaker","at 230 V rated value":"4 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 starter combinations","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":"500","at AC in hot operating state":"9.25 W","at AC-3 at 400 V rated value":"16 A","Of Auxiliary Contacts Typical":"500","Substance Prohibitance (Date)":"10/01/2009","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"16 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":"3.1 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","Finely Stranded Without Core End Processing":"2x (1 ... 6 mm²)","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":"500","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":"208 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/74e355f7d32444fbec0d7ddfe66590cf.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=616417&mlfb=3RV2321-4AC20-0BA0"},"ai":{"faq":[{"question":"Where can I buy the 3RV2321-4AC20-0BA0 and how is it quoted?","answer":"It is sourced through independent distribution channels and quoted to order against an RFQ. Availability and current pricing are confirmed at quote time — no stock count or price is published here."},{"question":"What is the breaking capacity of the 3RV2321-4AC20-0BA0 at 400 V?","answer":"At 400 V AC the rated breaking capacity is 55 kA. The backup fuse limit at the same voltage is gG 63 A."},{"question":"What clearance is needed above and below this circuit breaker on DIN rail?","answer":"You need 50 mm clearance upwards and 50 mm downwards. Side clearance is 30 mm. Forward and backward clearance is zero — it can sit flush against the backplane."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RV2321-4AC20-0BA0","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/3RV2321-4AC20-0BA0 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}}