{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK4340-3LR51-0BA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK4340-3LR51-0BA0","canonicalUrl":"https://aoctrl.com/siemens/3RK4340-3LR51-0BA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RK4340-3LR51-0BA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RK4340-3LR51-0BA0 motor starter MCU, I/O controlled, direct starter, 6.3 A at 400 V AC-3, 3-pole, IP55, Trip Class 10, 145 x 182 x 220 mm.","salesMarkdown":"## Motor starting duty and protection profile The 3RK4340-3LR51-0BA0: Short-circuit protection is handled by upstream circuit breakers, not integrated fuses. The unit is rated for up to 80 operating cycles per hour, which suits intermittent-duty conveyors, pumps, and fans rather than high-speed indexing applications. ## Control voltage and I/O requirements Control supply is 20.4–26.4 V DC — a standard 24 V DC panel rail is fine as long as it stays within that window under load. The starter has no digital inputs onboard (0 digital inputs), so all I/O control is handled externally via the I/O-controlled interface designation. No PROFIBUS DP, PROFINET, or AS-Interface protocol support is built in. Communication is handled through the I/O-controlled interface; the unit itself is a non-bus device. Brake control outputs for DC or AC brake coils are not included — this is a motor-start-only variant. ## Physical integration and mounting constraints Dimensions are 145 mm deep, 182 mm wide, 220 mm high — this is a compact footprint for a direct starter with integrated overload. The IP55 enclosure rating means the housing is dust-protected and water-jet resistant, suitable for installation in washdown zones or dusty panel environments without a secondary enclosure. This flexibility helps when the starter must fit into a crowded backplate or align with cable entry points, but the tilt limits should be respected to keep the bimetal trip calibration within spec. ## Lifecycle and compliance documentation No UL or CSA listing is explicitly stated in the available records, but the part carries the Siemens SIRIUS brand designation which typically includes CE and UKCA marking for European markets. The IEC 81346-2 reference code Q confirms its function as a motor starter in the equipment hierarchy.","metaTitle":"Siemens 3RK4340-3LR51-0BA0 SIRIUS Motor Starter, 6.3 A AC-3","metaDescription":"Siemens SIRIUS 3RK4340-3LR51-0BA0 motor starter MCU, 6.3 A at 400 V AC-3, IP55, Trip Class 10. Active production; sourced to order. Request a quote.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Starters"],"specifications":{"Depth":"145 mm","Width":"182 mm","title":"3RK4340-3LR51-0BA0","Height":"220 mm","Trip Class":"CLASS 10","description":"SIRIUS MCU motor starter Enclosure degree of protection IP55 plastic Communication without electromechanically switching Short-circuit protection with circuit breaker DOL starter Brake without Performance class 6.30 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":"No","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, I/O controlled","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":"6.3 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":"6.3 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":"No","with high demand rate according to SN 31920":"75 %","operating power at AC-3 at 400 V rated value":"2.2 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","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":"4.5 ... 6.3 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/0a967de1f38fa0db9b381cd0d339cc67.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=272658&mlfb=3RK4340-3LR51-0BA0"},"ai":{"faq":[{"question":"What is the AC-3 rated current of 3RK4340-3LR51-0BA0 at 400 V?","answer":"This is the value to use when sizing the starter for a motor load."},{"question":"Can 3RK4340-3LR51-0BA0 replace a 3RT2028-1BB40 contactor in an existing panel?","answer":"No — this is an integrated motor starter MCU with bimetal overload protection and I/O control, not a bare contactor. The 3RT2028-1BB40 is a separate contactor without integrated overload or the same mounting footprint. Panel rewiring and a different control scheme would be required."},{"question":"What compliance documentation is available for 3RK4340-3LR51-0BA0?","answer":"As a Siemens SIRIUS product it typically includes CE marking for the European market. Specific UL or CSA documentation is not confirmed in the available records."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK4340-3LR51-0BA0","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/3RK4340-3LR51-0BA0 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}}