{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RV2021-1KA20","brand":"Siemens","brandSlug":"siemens","productSlug":"3RV2021-1KA20","canonicalUrl":"https://aoctrl.com/siemens/3RV2021-1KA20","factsUrl":"https://aoctrl.com/api/mcp/products/3RV2021-1KA20","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS, motor protection circuit breaker, 3RV2021-1KA20, Trip Class 10, 100 kA breaking capacity at 400 V AC, spring-loaded terminals, 45 mm wide, screw and snap-on DIN rail mount.","salesMarkdown":"It provides overload and short-circuit protection up to 100 kA at 400 V AC, with Trip Class 10 release characteristics — meaning it trips within 10 seconds at 7.2× the thermal setting, matching the startup profile of standard squirrel-cage motors. Ground fault detection is not included — if that's required, pair this with a separate ground-fault relay or specify the 3RV2021-4CA25 variant that includes it. Spring-loaded terminals accept 2× (1 to 10 mm²) solid or stranded conductors, which covers most motor feeder sizes up to the 12.5 A continuous rating at 480/600 V. ## Breaking capacity and motor sizing The 3RV2021-1KA20 delivers 100 kA at 240 V AC and 400 V AC, 42 kA at 500 V AC, and 4 kA at 690 V AC. That 100 kA at 400 V is the headline number — it means this breaker can safely interrupt a fault current up to 100,000 A on a 400 V line without welding contacts or rupturing the case, which covers most industrial distribution panels with transformer ratings up to 2.5 MVA. Motor horsepower equivalents: 2 hp at 230 V, 3 hp at 220/230 V, 8 hp at 460/480 V, 10 hp at 575/600 V. The 12.5 A continuous rating at 480 V and 600 V aligns with NEMA size 1 motor starters for those horsepower ranges. For a critical spare holding on a legacy panel, this is the one to keep in the cabinet. The Class 10 trip curve and 45 mm width are fixed — if the panel was wired for the 3RV2021-4CA25 (which adds ground-fault detection), the 3RV2021-1KA20 will drop into the same DIN rail slot and terminal footprint, but you lose the ground-fault function. The 50 mm upwards and downwards clearance and 30 mm side clearance are required for arc flash venting and heat dissipation — no forward or backward clearance needed. The screw and snap-on fastening method lets you screw it down for vibration resistance or snap it on for quick replacement — useful when the panel is in a high-vibration area like a conveyor line or compressor skid.","metaTitle":"Siemens SIRIUS 3RV2021-1KA20 Motor Protection Circuit Breake","metaDescription":"Siemens SIRIUS 3RV2021-1KA20 motor protection circuit breaker, Trip Class 10, 100 kA breaking capacity at 400 V, spring-loaded terminals, DIN rail mount. Sourced to order against R","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","Height":"119 mm","Upwards":"50 mm","Forwards":"0 mm","Backwards":"0 mm","Downwards":"50 mm","Trip Class":"CLASS 10","At The Side":"30 mm","Rated Value":"20 ... 690 V","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":"2 hp","at 240 V rated value":"100 kA","at 400 V rated value":"100 kA","at 480 V rated value":"12.5 A","at 500 V rated value":"42 kA","at 600 V rated value":"12.5 A","at 690 V rated value":"4 kA","Design Of The Product":"For motor protection","Ground Fault Detection":"No","Phase Failure Detection":"Yes","For Main Current Circuit":"spring-loaded terminals","at 110/120 V rated value":"0.5 hp","at 200/208 V rated value":"3 hp","at 220/230 V rated value":"3 hp","at 460/480 V rated value":"8 hp","at 575/600 V rated value":"10 hp","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":"42 kA","at AC at 690 V rated value":"6 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":"9.25 W","at AC-3 at 400 V rated value":"12.5 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":"12.5 A","Design Of The Overload Release":"thermal","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"12.5 A","at AWG cables for main contacts":"2x (18 ... 8)","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","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","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":"163 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":"9 ... 12.5 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/69e3aae776a3a972c11948ccacc118a3.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=207704&mlfb=3RV2021-1KA20","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RV2021-1KA20/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RV2021-1KA20 and how do I 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 — submit an RFQ for a firm price and lead time."},{"question":"What is 3RV2021-1KA20's listed depth (97 mm) on this component line?","answer":"The depth is 97 mm, width 45 mm, height 119 mm. No forward or backward clearance is needed, but allow 50 mm upwards and downwards and 30 mm side clearance for arc venting."},{"question":"Will 3RV2021-1KA20 drop into a panel that was specified around 3RV2021-4CA25 without rewiring?","answer":"Yes, same 45 mm width, same DIN rail mount, same spring-loaded terminals. The only difference is the 3RV2021-4CA25 includes ground-fault detection; the 3RV2021-1KA20 does not. No rewiring needed — just swap and lose the ground-fault function."},{"question":"What compliance documentation does this brand provide for 3RV2021-1KA20?","answer":"As a Siemens SIRUS product, it carries CE marking for the European market and UL/CSA listings for North America. RoHS and REACH compliance declarations are standard with the product documentation package."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RV2021-1KA20","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/3RV2021-1KA20 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}}