{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK4320-3CR51-0BA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK4320-3CR51-0BA0","canonicalUrl":"https://aoctrl.com/siemens/3RK4320-3CR51-0BA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RK4320-3CR51-0BA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS motor starter MCU for AS-Interface, 3RK4320-3CR51-0BA0, direct starter design, 1 A rated at AC-3 400 V, IP55, Trip Class 10, 340-440 V operating voltage.","salesMarkdown":"The operating voltage range is 340 to 440 V, with the control supply running on 20.4 to 26.4 V DC. The bimetal motor protection element handles the thermal model directly. IP55 enclosure means it handles dust ingress and water jets from any direction, suitable for installation in industrial environments where occasional washdown or hose-down cleaning occurs, though not rated for full immersion or high-pressure spray. ## Fieldbus and integration This starter communicates via AS-Interface protocol — no PROFINET or PROFIBUS DP on board. The AS-Interface bus carries both the control commands and the status feedback over a single two-wire cable, simplifying wiring in distributed I/O architectures. For plants already running AS-i, this drops straight into the network segment. The three-pole main current circuit handles the motor load. Short-circuit protection is provided by upstream circuit breakers.","metaTitle":"Siemens 3RK4320-3CR51-0BA0 SIRIUS Motor Starter","metaDescription":"Siemens SIRIUS 3RK4320-3CR51-0BA0 motor starter for AS-Interface. Direct starter, 1 A at AC-3 400 V, IP55, Trip Class 10.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Starters"],"specifications":{"Depth":"145 mm","Width":"182 mm","title":"3RK4320-3CR51-0BA0","Height":"220 mm","Trip Class":"CLASS 10","description":"SIRIUS MCU motor starter Enclosure degree of protection IP55 plastic Communication AS-Interface electromechanically switching Short-circuit protection with circuit breaker DOL starter Brake without Performance class 1.00 A Motor circuit breaker with bi-metal thermal Manual operation without 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":"IP55","PROFIBUS DP protocol":"No","Design Of The Product":"direct starter","Number Of Digital Inputs":"0","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":"No","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 ... +35 °C","Product Component Motor Brake Output":"No","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/335f9572f437350869b2063025005e45.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=90315&mlfb=3RK4320-3CR51-0BA0"},"ai":{"faq":[{"question":"Is the Siemens 3RK4320-3CR51-0BA0 a direct starter or a reversing starter?","answer":"It is a direct starter. The product design is explicitly listed as a direct starter, not a reversing or star-delta configuration. For reversing applications, you would need a second contactor and mechanical interlock."},{"question":"What voltage does 3RK4320-3CR51-0BA0 operate on?","answer":"The main circuit operating voltage is 340 to 440 V AC at 50/60 Hz. The control supply voltage is 20.4 to 26.4 V DC. The AS-Interface bus also provides power for the electronics."},{"question":"Does the 3RK4320-3CR51-0BA0 support PROFINET or PROFIBUS?","answer":"No. This motor starter supports AS-Interface protocol only. It does not support PROFINET or PROFIBUS DP. For PROFINET or PROFIBUS connectivity, a gateway or a different SIRIUS variant with the appropriate communication module would be needed."},{"question":"What is the mounting orientation for SIRIUS MCU starter 3RK4320?","answer":"The mounting position allows ±180° rotation on a vertical mounting surface and ±22.5° tilt forward or backward on a vertical surface. This flexibility helps fit the starter into confined cabinet spaces or align cable entries."},{"question":"Where can I buy the Siemens 3RK4320-3CR51-0BA0 motor starter?","answer":"This part is sourced to order against an RFQ. Availability and pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK4320-3CR51-0BA0","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/3RK4320-3CR51-0BA0 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}}