{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK4340-3MR51-1BA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK4340-3MR51-1BA0","canonicalUrl":"https://aoctrl.com/siemens/3RK4340-3MR51-1BA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RK4340-3MR51-1BA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS motor starter MCU, reversing starter, 8 A at AC-3 400 V, CLASS 10, IP55, 340–440 V operating voltage, 20.4–26.4 V DC control supply.","salesMarkdown":"## Reversing Starter with Bimetal Protection It carries an AC-3 rating of 8 A at 400 V, which is the motor-switching duty that governs real-world induction-motor loads; the CLASS 10 trip class means it will disconnect within 10 seconds under locked-rotor conditions, protecting the motor from overheating during a stall or hard start. Motor protection uses a bimetal overload relay integrated into the starter. Operating voltage is 340 to 440 V AC; control supply is 20.4 to 26.4 V DC. ## Enclosure and Mounting Flexibility Rated IP55, this starter is sealed against dust jets and low-pressure water — suitable for washdown areas or outdoor enclosures where a standard IP20 contactor would need a separate enclosure. Dimensions are 145 mm deep, 182 mm wide, and 220 mm high — a compact footprint for a reversing starter with integrated overload.","metaTitle":"Siemens 3RK4340-3MR51-1BA0 Motor Starter, CLASS 10, 8 A AC-3","metaDescription":"Siemens 3RK4340-3MR51-1BA0 SIRIUS motor starter MCU, reversing starter, 8 A at AC-3 400 V, CLASS 10, IP55, current lifecycle stage. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Starters"],"specifications":{"Depth":"145 mm","Width":"182 mm","title":"3RK4340-3MR51-1BA0","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 Reversing starter Brake without Performance class 8.00 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":"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":"reversing starter","Number Of Digital Inputs":"0","Short Circuit Protection":"Yes","at AC at 400 V rated value":"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":"No","brake control with 500 V DC":"No","Type Of The Motor Protection":"bimetal","at AC-3 at 400 V rated value":"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 ... +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":"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":"5.5 ... 8 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/ac46db5e218f4bcc0f590b11409925b5.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=229121&mlfb=3RK4340-3MR51-1BA0"},"ai":{"faq":[{"question":"Can 3RK4340-3MR51-1BA0 be used as a reversing starter?","answer":"Yes, its product design is explicitly a reversing starter, meaning it integrates the contactors and interlocking to reverse a three-phase motor's direction in a single housing."},{"question":"Where can I buy Siemens 3RK4340-3MR51-1BA0?","answer":"This part is sourced to order. 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/3RK4340-3MR51-1BA0","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/3RK4340-3MR51-1BA0 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}}