{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK1323-2AS51-1AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK1323-2AS51-1AA0","canonicalUrl":"https://aoctrl.com/siemens/3RK1323-2AS51-1AA0","factsUrl":"https://aoctrl.com/api/mcp/products/3RK1323-2AS51-1AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens ECOFAST reversing starter, AS-Interface, AC-3 4 kW / 400 V, 100 kA breaking capacity, IP65, thermistor motor protection, tab terminals, 91 x 130 x 250 mm.","salesMarkdown":"The Siemens 3RK1323-2AS51-1AA0 is an ECOFAST reversing starter — a self-contained motor-starting and reversing assembly in a plastic IP65 enclosure, rated for AC-3 duty up to 4 kW at 400 V. It integrates a mechanical switching contact, thermistor-based motor protection, and AS-Interface bus communication into one field-mounted unit, eliminating the separate contactor, overload relay, and enclosure that a conventional reversing starter would need. The 4 kW AC-3 rating at 400 V tells you this starter is sized for a standard 4-pole induction motor up to that power on a 400 V three-phase line — common for small conveyors, pumps, or reversing drives. Motor protection is via a thermistor input (PTC sensor embedded in the motor windings), not a bimetallic overload. That gives better thermal replication of the motor's actual temperature, especially under frequent starting or reversing duty where a standard thermal overload might nuisance-trip or fail to protect. The reversing function is built in — two mechanically interlocked contactors inside the same housing prevent simultaneous closure. ## AS-Interface integration and fieldbus constraints This starter communicates via AS-Interface (AS-i), not PROFIBUS DP. That means it connects to an AS-i master (typically a gateway to a higher-level PLC or fieldbus) using a two-wire flat cable that carries both power and data. The AS-i protocol is deterministic at 167 kHz and supports up to 62 slaves per segment — adequate for distributed motor control on a single machine or small line. No PROFIBUS DP interface is present, so if your control architecture uses PROFIBUS, you need an AS-i/PROFIBUS gateway. The enclosure dimensions — 130 mm wide, 250 mm high, 91 mm deep — are compact for a reversing starter with integrated bus and protection. It mounts directly to a machine frame or wall plate via the plastic housing's mounting lugs; no DIN rail is specified. The 10-pole motor outgoing feeder and 9-pole power connection are pre-wired to the tab terminals inside.","metaTitle":"Siemens 3RK1323-2AS51-1AA0 ECOFAST Reversing Starter, 4 kW A","metaDescription":"Siemens ECOFAST reversing starter, AS-Interface, 4 kW at 400 V AC-3, 100 kA breaking capacity, IP65, thermistor motor protection. Current lifecycle. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Remote I/O & Fieldbus Modules"],"specifications":{"Depth":"91 mm","Width":"130 mm","Height":"250 mm","Maximum":"500 V","Minimum":"400 V","Initial Value":"0.3 A","Type of voltage":"DC","lifecycle_stage":"current","Full-scale value":"9 A","Type of assignment":"1","Protection class IP":"IP65","PROFIBUS DP protocol":"No","AS-interface protocol":"Yes","Design of the product":"reversing starter","Type of the motor protection":"thermistor","Design of the switching contact":"mechanical","Design of short-circuit protection":"fuse","Product function Bus communication":"Yes","Ambient temperature during operation":"-20 ... +40 °C","Product component Motor brake output":"No","Equipment marking acc. to DIN EN 61346-2":"Q","Operating power at AC-3 at 400 V rated value":"4 000 W","Type of electrical connection for main current circuit":"tab terminals","Maximum short-circuit current breaking capacity (Icu) at 400 V rated value":"100 kA"}},"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=274239&mlfb=3RK1323-2AS51-1AA0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RK1323-2AS51-1AA0/alternatives.json"},"ai":{"faq":[{"question":"What are the key ratings for this reversing starter?","answer":"It is rated for AC-3 duty up to 4 kW at 400 V, with a short-circuit breaking capacity of 100 kA at 400 V. The enclosure is IP65, and motor protection is via thermistor input. Communication is AS-Interface only."},{"question":"What are the physical dimensions of the 3RK1323-2AS51-1AA0?","answer":"The enclosure measures 130 mm wide, 250 mm high, and 91 mm deep."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK1323-2AS51-1AA0","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/3RK1323-2AS51-1AA0 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}}