{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK1303-5CS44-3AA3","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK1303-5CS44-3AA3","canonicalUrl":"https://aoctrl.com/siemens/3RK1303-5CS44-3AA3","factsUrl":"https://aoctrl.com/api/mcp/products/3RK1303-5CS44-3AA3","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RK3 reversing starter, 3RK1303-5CS44-3AA3, IP65, PROFIBUS DP, 9 A at AC-3 400 V, 100 kA SCCR, solid-state motor protection, 4 digital inputs.","salesMarkdown":"The Siemens 3RK1303-5CS44-3AA3 is a reversing starter in the SIRIUS 3RK3 family, designed for direct-on-line reversing of three-phase motors up to 9 A in AC-3 duty at 400 V. This is the current-carrying capacity for switching motor loads under full load — the 9 A AC-3 rating governs the motor FLA it can handle, not the thermal continuous current. The unit integrates a solid-state motor protection function, so it provides overload and phase-loss protection without a separate thermal relay. It operates on a 24 V DC control supply (20.4 to 28.8 V range) and communicates via PROFIBUS DP. This makes it suitable for washdown areas or outdoor cabinets where a standard IP20 panel-mount starter would require a separate enclosure. The 100 kA rated short-circuit current at 400 V (SCCR) means this starter can be installed on a supply capable of delivering up to 100 kA fault current without needing upstream current-limiting fuses to protect it. That simplifies panel coordination — you can feed it from a transformer or busway with a high available fault current and still meet code. The short-circuit protection is fuse-based, so the incoming line-side fuses must be selected to coordinate with the solid-state overload. Brake control with 400 V AC is built in — the starter can directly switch a 400 V AC brake coil for holding brakes on vertical-axis motors, eliminating a separate contactor. The load-side outgoing feeder uses an ISO23570 socket, so the motor cable plugs in with a standardized connector rather than hard-wired terminals. This reduces wiring time and makes swap-out faster. Four digital inputs (M12 sockets) are onboard and parameterizable, giving two dedicated inputs for feedback or limit switches. There are no digital outputs on this variant — the reversing contactor status is communicated via PROFIBUS DP rather than hard-wired auxiliary contacts. The mechanical switching contacts are rated for fewer than 1 error per 100 million operating cycles, which is the expected mechanical endurance for the contactor block. ## Where it goes in a panel or machine This is a self-contained reversing starter in an IP65 enclosure — it mounts directly on the machine frame or a wall bracket, not inside a control cabinet. The hybrid plug for line-side supply and the hybrid socket for communication transmission mean you run one hybrid cable for both power and PROFIBUS DP to the unit. The supply voltage line-side connection uses a hybrid plug as well, so the entire wiring interface is a single multi-conductor cable per unit. The form factor is 250 mm high, 130 mm wide, 107 mm deep — compact enough for distributed installation on a conveyor line or packaging machine where individual motor starters are mounted near the motor rather than in a central MCC. The minimum operating frequency of 1 switching cycle per hour is the lower bound for the mechanical contactor; for applications requiring frequent reversing (e.g., shuttle tables), verify the duty cycle against the application. The substance prohibition date of 05/01/2012 reflects RoHS compliance (the EU RoHS exemption sunset for certain substances). The unit is RoHS-compliant per that date. No UL or CSA listing is explicitly stated in the evidence; verify local code acceptance for the specific installation jurisdiction.","metaTitle":"Siemens 3RK1303-5CS44-3AA3 Reversing Starter, IP65, 9 A AC-3","metaDescription":"Siemens reversing starter with PROFIBUS DP, rated 9 A at AC-3 400 V, IP65 enclosure, 100 kA SCCR. Active lifecycle, solid-state motor protection. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Remote I/O & Fieldbus Modules"],"specifications":{"Depth":"107 mm","Width":"130 mm","at DC":"24 ... 24 V","Height":"250 mm","Type Of Voltage":"DC","lifecycle_stage":"current","Bus Communication":"Yes","PROFINET protocol":"No","at DC rated value":"20.4 ... 28.8 V","Type Of Assignment":"1","Maximum Permissible":"28.8 V","Minimum Permissible":"20.4 V","protection class IP":"IP65","PROFIBUS DP protocol":"Yes","at 400 V rated value":"100 kA","Design Of The Product":"reversing starter","Of Auxiliary Contacts":"< 1 error per 100 million operating cycles","For Main Energy Infeed":"socket according to ISO23570","supply voltage 1 at DC":"24 ... 24 V","Number Of Digital Inputs":"4","Short Circuit Protection":"Yes","For Digital Input Signals":"2","For Digital Output Signals":"0","1 For Digital Input Signals":"M12 socket","2 For Digital Input Signals":"M12 socket","Operating Frequency Minimum":"1 1/h","brake control with 400 V AC":"Yes","For Supply Voltage Line-Side":"hybrid plug","Type Of The Motor Protection":"solid-state","at AC-3 at 400 V rated value":"9 A","For Load-Side Outgoing Feeder":"socket according to ISO23570","Operating Voltage Rated Value":"400 ... 500 V","Substance Prohibitance (Date)":"05/01/2012","Digital Inputs Parameterizable":"Yes","For Communication Transmission":"hybrid socket","Of The Communication Interface":"hybrid plug","Design Of The Switching Contact":"mechanical","Digital Outputs Parameterizable":"No","For Supply Voltage Transmission":"hybrid socket","Design Of Short-Circuit Protection":"fuse","Ambient Temperature During Operation":"-20 ... +40 °C","Product Component Motor Brake Output":"Yes","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 ... 28.8 V","design of the interface PROFINET protocol":"No","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":"4 000 W","At The Manufacturer-Specific Device Interface":"M12 socket","Type Of Voltage Of The Control Supply Voltage":"DC","Type Of Electrical Connection For Main Current Circuit":"tab terminals","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"2.4 ... 9 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=248098&mlfb=3RK1303-5CS44-3AA3","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RK1303-5CS44-3AA3/alternatives.json"},"ai":{"faq":[{"question":"What communication protocols does it support?","answer":"It supports PROFIBUS DP. PROFINET is not supported on this variant. The bus communication interface uses a hybrid plug for both power and data transmission."},{"question":"What enclosure rating does it have?","answer":"Protection class is IP65. The enclosure is dust-tight and protected against low-pressure water jets from any direction, suitable for washdown environments or outdoor installation without a separate cabinet."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK1303-5CS44-3AA3","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/3RK1303-5CS44-3AA3 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}