{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK4320-3BQ51-0BA3","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK4320-3BQ51-0BA3","canonicalUrl":"https://aoctrl.com/siemens/3RK4320-3BQ51-0BA3","factsUrl":"https://aoctrl.com/api/mcp/products/3RK4320-3BQ51-0BA3","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RK4320-3BQ51-0BA3 motor starter MCU for AS-Interface, direct starter, 0.8 A AC-3 at 400 V, Class 10 trip, IP54, 205 x 245 x 215 mm.","salesMarkdown":"The 3RK4320-3BQ51-0BA3: It integrates motor protection, switching, and bus communication into a single unit, eliminating the need for separate contactor, overload relay, and gateway in many distributed motor control applications. Rated 0.8 A at AC-3 at 400 V, this starter is sized for small motors — fractional-horsepower pumps, fans, or conveyor drives — where the full-load current stays under that threshold. The Class 10 trip characteristic means it disconnects within 10 seconds at 600% of the set current, protecting the motor from locked-rotor events without nuisance tripping on normal starts. The unit includes a motor brake output (400 V AC) and two digital inputs, so it can handle basic local control and brake commands directly, reducing wiring back to a central panel. ## Panel fit and mounting flexibility Dimensions are 205 mm deep, 245 mm wide, and 215 mm high — a compact footprint for a combined starter-and-bus node. The enclosure is rated IP54, meaning it's protected against dust ingress and splashing water, suitable for installation in industrial environments where washdown or airborne particulates are a concern. Mounting is flexible: the unit can be rotated ±180° on a vertical surface and tilted forward or backward by ±22.5°, allowing it to fit into tight or awkward panel layouts without forcing a rework of the backplate. ## Power supply and operating conditions Short-circuit protection is provided by circuit breakers (integrated or upstream), and the unit is designed for a maximum operating frequency of 80 cycles per hour — sufficient for intermittent-duty applications like indexing conveyors or batch mixers.","metaTitle":"Siemens 3RK4320-3BQ51-0BA3 SIRIUS Motor Starter, 0.8 A AC-3","metaDescription":"Siemens SIRIUS 3RK4320-3BQ51-0BA3 motor starter MCU for AS-Interface, 0.8 A AC-3 at 400 V, Class 10 trip, IP54. Active production, quoted to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Starters"],"specifications":{"Depth":"205 mm","Width":"245 mm","title":"3RK4320-3BQ51-0BA3","Height":"215 mm","Trip Class":"CLASS 10","description":"SIRIUS MCU motor starter Enclosure degree of protection IP54 metal Communication AS-Interface electromechanically switching Short-circuit protection with circuit breaker DOL starter Brake 400 V AC (internal) Performance class 0.80 A Motor circuit breaker with bi-metal thermal Rotary operating mechanism gray/black Connection power M screw connection Standard product","Type Of Voltage":"DC","lifecycle_stage":"current","Bus Communication":"Yes","Mounting Position":"+/-180° rotation possible on vertical mounting surface; can be tilted forward and backward by +/- 22.5° on vertical mounting surface","PROFINET protocol":"No","Product Brand Name":"SIRIUS","Type Of Assignment":"1","Product Designation":"motor starter MCU for AS-Interface","protection class IP":"IP54","PROFIBUS DP protocol":"No","Design Of The Product":"direct starter","Number Of Digital Inputs":"2","Short Circuit Protection":"Yes","at AC at 400 V rated value":"0.8 A","brake control with 24 V DC":"No","Operating Frequency Minimum":"80 1/h","brake control with 180 V DC":"No","brake control with 400 V AC":"Yes","brake control with 500 V DC":"No","Type Of The Motor Protection":"bimetal","at AC-3 at 400 V rated value":"0.8 A","Operating Voltage Rated Value":"340 ... 440 V","Substance Prohibitance (Date)":"05/01/2012","Design Of The Switching Contact":"electromechanical","Operating Frequency 1 Rated Value":"50 Hz","Operating Frequency 2 Rated Value":"60 Hz","Design Of Short-Circuit Protection":"circuit-breakers","Ambient Temperature During Operation":"-25 ... +50 °C","Product Component Motor Brake Output":"Yes","Type Of Voltage Of The Supply Voltage":"DC","reference code according to IEC 81346-2":"Q","Number Of Poles For Main Current Circuit":"3","control supply voltage at DC rated value":"20.4 ... 26.4 V","with low demand rate according to SN 31920":"50 %","protocol is supported AS-Interface protocol":"Yes","with high demand rate according to SN 31920":"75 %","operating power at AC-3 at 400 V rated value":"0.2 kW","Product Extension Braking Module For Brake Control":"No","Relative Negative Tolerance Of The Operating Frequency":"-10 %","Relative Positive Tolerance Of The Operating Frequency":"10 %","Type Of Electrical Connection For Main Current Circuit":"screw-type terminals","maximum short-circuit current breaking capacity (Icu) at 400 V rated value":"50 000 A","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"0.55 ... 0.8 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/5f7f2b954889260249f11602d5ed37bf.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=222177&mlfb=3RK4320-3BQ51-0BA3"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK4320-3BQ51-0BA3","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/3RK4320-3BQ51-0BA3 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}}