{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK4320-3CQ51-0BA3","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK4320-3CQ51-0BA3","canonicalUrl":"https://aoctrl.com/siemens/3RK4320-3CQ51-0BA3","factsUrl":"https://aoctrl.com/api/mcp/products/3RK4320-3CQ51-0BA3","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RK4320-3CQ51-0BA3 motor starter MCU for AS-Interface, direct starter, 1 A at AC-3 400 V, Class 10, IP54, 205×245×215 mm.","salesMarkdown":"## AS-Interface bus integration and motor protection The 3RK4320-3CQ51-0BA3: This is a direct starter (non-reversing) with electromechanical switching contacts and bimetal motor protection rated Class 10 — the standard trip class for general-purpose motor starting, protecting against overload without nuisance tripping on normal start-up inrush. It communicates over AS-Interface protocol (not PROFINET or PROFIBUS), so it drops into an AS-i network without a gateway for the motor starter itself. The control supply is 20.4–26.4 V DC, which matches the AS-Interface bus power voltage range. Rated 1 A at AC-3 400 V — this is the motor switching current, not a resistive load rating. The AC-3 duty covers starting and switching off squirrel-cage motors during running; the 1 A figure limits the connected motor size to roughly 0.37–0.55 kW at 400 V three-phase. ## Panel fit and mounting flexibility Dimensions are 205 mm deep, 245 mm wide, 215 mm high — plan for a back-panel footprint of about 245×215 mm plus clearance for cabling and heat dissipation. The enclosure rating is IP54, so it is dust-protected and splash-resistant, suitable for control cabinets or light industrial floors. Two digital inputs are available for local feedback or auxiliary signals; the unit also includes a motor brake output (400 V AC) and short-circuit protection via circuit-breakers.","metaTitle":"Siemens 3RK4320-3CQ51-0BA3 SIRIUS Motor Starter","metaDescription":"Siemens 3RK4320-3CQ51-0BA3 SIRIUS motor starter MCU for AS-Interface, direct starter, 1 A at AC-3 400 V, Class 10, 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":"3RK4320-3CQ51-0BA3","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 1.00 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":"1 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":"1 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":"0.3 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":"0.7 ... 1 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/fcfbb9576e17a55b55db2c2fa7c34b5a.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=134221&mlfb=3RK4320-3CQ51-0BA3"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK4320-3CQ51-0BA3","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/3RK4320-3CQ51-0BA3 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}}