{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RV6321-4BC10","brand":"Siemens","brandSlug":"siemens","productSlug":"3RV6321-4BC10","canonicalUrl":"https://aoctrl.com/siemens/3RV6321-4BC10","factsUrl":"https://aoctrl.com/api/mcp/products/3RV6321-4BC10","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RV6321-4BC10, size S0 circuit breaker for starter combinations, 3-pole, 20 A AC-3 at 400 V, 690 V rated, screw terminals, 260 A instantaneous magnetic trip.","salesMarkdown":"## What this breaker does on the line The Siemens SIRIUS 3RV6321-4BC10 is a three-pole circuit breaker built for starter combinations — meaning it lives right ahead of a contactor in a motor branch circuit. It gives you both overload and short-circuit protection in one package, and the magnetic instantaneous trip is set at 260 A, so it clears a fault fast before the contactor takes damage. Rated operational current is 20 A in AC-3 duty at 400 V, which covers a fair range of small-to-mid motor loads on a 50/60 Hz line. This is a size S0 frame, which is the compact workhorse form factor in the SIRIUS line — 45 mm wide, 97 mm tall, 96 mm deep. Power loss is 8 W typical, so it won't cook the enclosure if you've got a row of them. ## Mounting and wiring in the panel Clearance requirements: 50 mm above and below, 30 mm to the sides, zero forward or backward — so you can butt it against a backplane or gland plate without extra breathing room. Terminals are screw-type on top and bottom, accepting 2x (1 to 2.5 mm²) solid/stranded or 2x (2.5 to 10 mm²). Torque to 2 to 2.5 N·m on the main contacts. AWG equivalents are 2x (16 to 12) and 2x (14 to 8). RoHS compliance date is noted as May 1, 2012, which covers the EU RoHS directive. Relative humidity tolerance is 10 to 95% during operation. Shock resistance per IEC 60068-2-27 is 25 g for 11 ms. Installation altitude max is 2000 m above sea level.","metaTitle":"Siemens 3RV6321-4BC10 SIRIUS Circuit Breaker, 20 A AC-3, 690","metaDescription":"Siemens SIRIUS 3RV6321-4BC10 circuit breaker for starter combinations. 20 A AC-3 at 400 V, 690 V rated, 260 A instantaneous trip. Screw terminals, size S0. Available to order, quot","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Protection Circuit Breakers (MPCB)"],"specifications":{"Depth":"96 mm","Width":"45 mm","Height":"97 mm","Upwards":"50 mm","Forwards":"0 mm","Backwards":"0 mm","Downwards":"50 mm","At The Side":"30 mm","Rated Value":"690 V","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","Mounting Position":"any","Solid Or Stranded":"2x (1 ... 2.5 mm²), 2x (2.5 ... 10 mm²)","Product Brand Name":"SIRIUS","Product Designation":"Circuit breaker","Design Of The Product":"for starter combinations","For Main Current Circuit":"screw-type terminals","Size Of The Circuit-Breaker":"S0","at AC-3 rated value maximum":"690 V","power loss [W] total typical":"8 W","Substance Prohibitance (Date)":"05/01/2012","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"20 A","at AWG cables for main contacts":"2x (16 ... 12), 2x (14 ... 8)","Design Of The Short-Circuit Trip":"magnetic","Relative Humidity During Operation":"10 ... 95 %","operating frequency at AC-3 maximum":"15 1/h","Surge Voltage Resistance Rated Value":"6 kV","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","For Main Contacts With Screw-Type Terminals":"2 ... 2.5 N·m","shock resistance according to IEC 60068-2-27":"25g / 11 ms","operational current at AC-3 at 400 V rated value":"20 A","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":"260 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V","breaking capacity maximum short-circuit current (Icu) at AC at 400 V rated value":"55 kA","breaking capacity operating short-circuit current (Ics) at AC at 400 V rated value":"25 kA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/a14fa4add315801bb944a6300267c375.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=621314&mlfb=3RV6321-4BC10","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RV6321-4BC10/alternatives.json"},"ai":{"faq":[{"question":"What are the key ratings for 3RV6321-4BC10?","answer":"Rated operational current 20 A at AC-3, 400 V; insulation voltage 690 V; instantaneous short-circuit trip set at 260 A; rated impulse withstand voltage 6 kV; operating frequency 50/60 Hz."},{"question":"What compliance documentation does this breaker carry?","answer":"RoHS compliance dated May 1, 2012. Shock tested per IEC 60068-2-27 at 25 g / 11 ms. Operating temperature range -20 to +60 °C."},{"question":"Where can I buy 3RV6321-4BC10 and how is it quoted?","answer":"Sourced through independent industrial-automation distribution. Quoted to order against an RFQ; availability and current pricing confirmed at the time of quote."},{"question":"Will 3RV6321-4BC10 drop into a panel wired for 3RV6021-4DA10?","answer":"Both are size S0 frames on 35 mm DIN rail, same mounting footprint. The 3RV6321-4BC10 carries a 20 A AC-3 rating versus the peer's rating; verify the trip curve and instantaneous setting match your motor FLA before swapping. Wiring terminals are the same screw-type arrangement."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RV6321-4BC10","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/3RV6321-4BC10 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}}