{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK4320-3AQ51-1BA3","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK4320-3AQ51-1BA3","canonicalUrl":"https://aoctrl.com/siemens/3RK4320-3AQ51-1BA3","factsUrl":"https://aoctrl.com/api/mcp/products/3RK4320-3AQ51-1BA3","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RK4320-3AQ51-1BA3 reversing motor starter, AS-Interface bus communication, 0.63 A AC-3 at 400 V, CLASS 10 bimetal overload protection, IP54, 3-pole, DC control supply 20.4–26.4 V.","salesMarkdown":"## AS-Interface reversing starter with CLASS 10 bimetal protection The Siemens 3RK4320-3AQ51-1BA3 is a SIRIUS reversing motor starter designed for AS-Interface bus communication — it switches and protects a motor in both directions without a separate reversing contactor pair. ## Bus integration and control supply AS-Interface protocol is supported natively, so the starter connects directly to the AS-i yellow cable — no separate gateway module for the motor branch. The control supply is 20.4–26.4 V DC, drawn from the AS-Interface power supply unit. Two digital inputs are available on the unit for local pushbuttons or limit switches, reducing the need for a separate I/O block at the motor. ## Mounting, enclosure, and environmental limits IP54 protection suits installation in control cabinets or enclosed machine cells where occasional dust and splash ingress may occur. Dimensions are 245 mm wide, 215 mm high, 205 mm deep. ## Motor brake output and short-circuit protection The unit includes a motor brake output controllable with 400 V AC — for applications like conveyors or hoists that need a holding brake, the starter supplies the brake coil directly. Short-circuit protection is provided via circuit-breakers; the starter itself is not a stand-alone SC protection device, so an upstream breaker sized to the branch is required.","metaTitle":"Siemens 3RK4320-3AQ51-1BA3 SIRIUS reversing starter, 0.63 A","metaDescription":"Siemens SIRIUS 3RK4320-3AQ51-1BA3 reversing motor starter, AS-Interface, 0.63 A AC-3 at 400 V, CLASS 10 bimetal protection, IP54, active production.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Motor Starters"],"specifications":{"Depth":"205 mm","Width":"245 mm","title":"3RK4320-3AQ51-1BA3","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 Reversing starter Brake 400 V AC (internal) Performance class 0.63 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":"reversing starter","Number Of Digital Inputs":"2","Short Circuit Protection":"Yes","at AC at 400 V rated value":"0.63 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":"0.63 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":"0.2 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":"0.45 ... 0.63 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/99d315c5cf0bb3ba7e761cffe3c76174.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=254027&mlfb=3RK4320-3AQ51-1BA3"},"ai":{"faq":[{"question":"What is the motor current rating and trip class?","answer":"Rated 0.63 A at AC-3, 400 V with a CLASS 10 bimetal overload relay. The CLASS 10 trip curve provides fast disconnection on locked-rotor conditions, matching standard induction motor thermal characteristics."},{"question":"What compliance documentation does Siemens provide for this part?","answer":"The unit carries the SIRIUS brand and is designed to relevant IEC/EN standards; a declaration of conformity is available from Siemens upon request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK4320-3AQ51-1BA3","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/3RK4320-3AQ51-1BA3 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}}