{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK1408-8KG00-0AA2","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK1408-8KG00-0AA2","canonicalUrl":"https://aoctrl.com/siemens/3RK1408-8KG00-0AA2","factsUrl":"https://aoctrl.com/api/mcp/products/3RK1408-8KG00-0AA2","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS 3RK1408-8KG00-0AA2 AS-Interface ground fault module, IP20, 22.5 mm width, spring-loaded terminals, DC-12 1 A relay output, 24 V 500 mA / 48 V 200 mA.","salesMarkdown":"## AS-Interface Ground Fault Module with Relay Output The Siemens 3RK1408-8KG00-0AA2 is an AS-Interface ground fault detection module designed for monitoring the AS-i cable for earth faults. The module's relay output is rated DC-12 at 1 A, with a mechanical endurance of 2,000,000 operating cycles. For inductive loads, the manufacturer recommends freewheel diodes across the load to extend relay life. The auxiliary supply (Uaux) should be protected by a 2 A slow-blow fuse. Switching capacity is specified at 24 V for 500 mA and 48 V for 200 mA — these are the DC-13 resistive/inductive load ratings that govern real-world contactor or indicator lamp switching. The module draws up to 40 mA from the AS-Interface bus for its own electronics. ## Ground Fault Detection Logic The module detects an earth fault when the AS-Interface cable voltage to ground (Ugnd) falls between 10% and 90% of the nominal Uas-i. It provides a remote reset input and two signaling relay outputs for fault annunciation. If repeaters are used in the network, each AS-Interface segment requires its own ground fault detection module — one per power supply unit. The module does not perform overvoltage detection and has no counter function. Its sole purpose is ground fault monitoring on the AS-i bus, making it a targeted component for maintaining bus integrity rather than a general-purpose I/O slice. ## Lifecycle Status: Not Recommended for New Designs The 3RK1408-8KG00-0AA2 carries a manufacturer lifecycle status of NRND (Not Recommended for New Designs). This means Siemens will continue to support existing installations and fulfill orders for current production runs, but the part should not be specified into new BOMs. Its 22.5 mm width matches the standard AS-interface module footprint, allowing side-by-side mounting with other SIRIUS 3RK1 devices. The spring-loaded terminals accept 2 x (0.25 – 1.5) mm² solid or stranded wire (2 x (0.25 – 1.0) mm² with end sleeves). IP20 rated — suitable for enclosed control panels only, not for washdown or outdoor locations. The rated temperature for all electrical specifications is 25 °C.","metaTitle":"Siemens 3RK1408-8KG00-0AA2 AS-i Ground Fault Module, NRND","metaDescription":"Siemens 3RK1408-8KG00-0AA2 AS-Interface ground fault module, IP20, 22.5mm wide. DC-12 1A relay output, 24V 500mA / 48V 200mA. NRND — sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"NRND","categoryPath":["Remote I/O & Fieldbus Modules"],"specifications":{"24 V":"500mA","48 V":"200mA","DC-12":"1A","Depth":"86mm","Solid":"2 x (0.25 - 1.5) mm²","Width":"22.5mm","title":"3RK1408-8KG00-0AA2","Height":"103mm","Note 1":"If repeaters are used, a ground fault detection module must be used for each AS-Interface segment (number of AS-Interface power supply units = number of ground fault detection modules)","Note 2":"Uaux should be protected by a 2 A slow fuse. The endurance of the relay can be increased if inductive loads are connected using freewheel diodes.","Counter":"No","Lin Min":"6mA","Uin min":"10V","Addressing":"the module does not need its own AS-Interface address","Earth fault":"10% Uas-i <= Ugnd <= 90% Uas-i","description":"AS-i ground fault module IP20 S22.5, ground fault monitoring 1 input, remote reset 2 x signaling output, Relay DC-12 1 A / DC-13 500 mA (24 V) Spring-type terminal Overall width 22.5 mm No AS-i address required Only AS-Interface monitoring","During Storage":"-40 ... +85°C","With End Sleeve":"2 x (0,25 - 1) mm²","lifecycle_stage":"current","During Operation":"-25 ... +70°C","Fastening Method":"standard rail mounting/wall mounting","Rated temperature":"25°C","Low Signal Lin Max":"1.5mA","Without End Sleeve":"2 x (0.25 - 1.5) mm²","protection class IP":"IP20","AWG solid or stranded":"AWG 2 x (24 - 16) mm²","Design Of The Product":"ground-fault detection modules - modules with special functions","Overvoltage Detection":"No","Ground Fault Detection":"Yes","Operating cycles DC-12":"2 000 000","Rated operational voltage DC":"24 ... 48V","AS interface total current input max":"40mA","reference code according to EN 61346-2":"K","protocol is supported AS-Interface protocol":"Yes","AS interface Connection Polarity reversal protection":"built-in","Type Of Electrical Connection Of The Inputs And Outputs":"spring-loaded terminals"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$104.14","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/dd1c24c76ded8b46518cb92e8bdc38f0.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=526831&mlfb=3RK1408-8KG00-0AA2"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK1408-8KG00-0AA2","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/3RK1408-8KG00-0AA2 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-20T14:41:02.429Z","lastPublished":"2026-07-20T14:41:02.429Z","indexable":true}}