{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK4320-3FQ51-0BA2","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK4320-3FQ51-0BA2","canonicalUrl":"https://aoctrl.com/siemens/3RK4320-3FQ51-0BA2","factsUrl":"https://aoctrl.com/api/mcp/products/3RK4320-3FQ51-0BA2","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RK4320-3FQ51-0BA2 motor starter MCU for AS-Interface, direct starter, 2 A AC-3 at 400 V, CLASS 10, IP54.","salesMarkdown":"It is a direct starter with electromechanical switching contacts and a CLASS 10 bimetal overload relay, rated for motor protection. This is a current-production part, so it remains a standard catalog item for new panel builds and legacy line expansions alike. No lifecycle phase-out has been announced. ## AS-Interface integration and supply The unit communicates natively over AS-Interface (no PROFIBUS or PROFINET onboard), making it a drop-in node for AS-i segmented fieldbus architectures. It provides 2 digital inputs for local sensors or pushbuttons, and includes a motor brake output component for controlled stopping of braked motors. Control supply is 20.4 to 26.4 V DC, which matches the standard AS-Interface power supply voltage range. ## Mounting, environment, and protection The enclosure measures 245 mm wide by 215 mm high by 205 mm deep and carries an IP54 protection class, meaning it is dust-protected and splash-resistant — suitable for installation inside a control cabinet or in a protected machine-mount location where occasional dust or condensation may occur.","metaTitle":"Siemens 3RK4320-3FQ51-0BA2 SIRIUS Motor Starter, 2 A AC-3","metaDescription":"Siemens SIRIUS 3RK4320-3FQ51-0BA2 motor starter MCU for AS-Interface. Rated 2 A at AC-3 400 V, CLASS 10, IP54. Current production. Sourced 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","Height":"215 mm","Trip Class":"CLASS 10","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":"2 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":"No","brake control with 500 V DC":"No","Type Of The Motor Protection":"bimetal","at AC-3 at 400 V rated value":"2 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":"0.8 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","breaking capacity maximum short-circuit current (Icu) at 400 V rated value":"50 000 A","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"1.4 ... 2 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=288413&mlfb=3RK4320-3FQ51-0BA2","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RK4320-3FQ51-0BA2/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy 3RK4320-3FQ51-0BA2 and how do I get a price?","answer":"We source this part to order against an RFQ. Submit a request for quote and we will confirm current availability and pricing at that time."},{"question":"Can 3RK4320-3FQ51-0BA2 be used with PROFINET?","answer":"No, this unit supports AS-Interface protocol only. It does not have PROFINET or PROFIBUS DP onboard. For PROFINET integration, you would need a gateway or a different motor starter variant."},{"question":"Does 3RK4320-3FQ51-0BA2 include a circuit breaker?","answer":"The unit is designed for use with circuit-breakers for short-circuit protection (listed as 'design of short-circuit protection: circuit-breakers'), but the circuit breaker itself is a separate component, not included in this motor starter MCU."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK4320-3FQ51-0BA2","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/3RK4320-3FQ51-0BA2 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}}