{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RK3921-1AA10","brand":"Siemens","brandSlug":"siemens","productSlug":"3RK3921-1AA10","canonicalUrl":"https://aoctrl.com/siemens/3RK3921-1AA10","factsUrl":"https://aoctrl.com/api/mcp/products/3RK3921-1AA10","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS modular safety system, starter kit 3RK3921-1AA10, 8 safety-related inputs, 2-channel, SIL CL 3, IP20, 124 x 111 x 45 mm.","salesMarkdown":"## What this SIRIUS starter kit does in a safety circuit The Siemens 3RK3921-1AA10 is a SIRIUS modular safety system starter kit — the base building block for a configurable safety controller in a control panel. It carries 8 safety-related inputs, all 2-channel, meaning every input expects a dual-channel signal pair from an E-stop, guard switch, or light curtain. That 2-channel architecture gives you SIL CL 3 per IEC 61508 and SIL 3 per IEC 62061, which is the level you need for guarding a hazard zone where a single fault must not lead to loss of the safety function. Response time sits at 1 ms at 24 V DC, so the safety reaction is fast enough for most machine guarding — a light curtain break or E-stop press stops the hazardous motion within that window. The input delay is adjustable from 0 to 150 ms, which lets you filter out contact bounce on mechanical guard switches without slowing the safety response beyond what the risk assessment allows. ## PROFIBUS DP and parameterization The starter kit supports PROFIBUS DP when used with the DP interface module, carrying 32-bit cyclical data. That means it talks to a PLC over the fieldbus for diagnostics and parameterization — you can adjust input delays, muting configurations, and start-up behavior from the controller without opening the panel. ## Wiring and environmental limits Shock resistance is 15g for 11 ms, which covers most industrial vibration environments.","metaTitle":"Siemens 3RK3921-1AA10 SIRIUS Modular Safety Starter Kit, 8 I","metaDescription":"Siemens 3RK3921-1AA10 SIRIUS modular safety system starter kit. 8 safety-related inputs, 2-channel, SIL CL 3 per IEC 61508. PROFIBUS DP, IP20. Current lifecycle stage. Quoted to or","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Safety Relays"],"specifications":{"Depth":"124 mm","Solid":"20 ... 14","Width":"45 mm","title":"3RK3921-1AA10","Height":"111 mm","at 24 V":"1 ms","Stranded":"20 ... 14","2-Channel":"1","description":"Starter package for modular Safety system 3RK3 Content: Central unit MSS Basic Connection: Screw terminal Software Safety ES V1.0 standard, PC cable","During Storage":"-40 ... +85 °C","Safety-Related":"8","Single Channel":"0","Of The Terminal":"IP20","Type Of Voltage":"DC","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-40 ... +85 °C","Fastening Method":"Snap-mounted to DIN rail or screw-mounted with additional push-in lug","Input Delay Time":"0 ... 150 ms","Of The Enclosure":"IP20","Product Category":"Modular Safety System","Shock Resistance":"15g / 11 ms","Valve Monitoring":"Yes","Mounting Position":"vertical","Monitored Start-Up":"Yes","Non-Safety-Related":"0","Product Brand Name":"SIRIUS","Degree Of Pollution":"3","Product Designation":"Starter kit","at AWG cables solid":"2x (20 ... 14)","protection class IP":"IP20","PROFIBUS DP protocol":"Yes; when using the DP interface module; 32 bit cyclical data","Parameterizable Inputs":"Yes","according to IEC 61508":"SIL CL 3","according to IEC 62061":"3","at AWG cables stranded":"2x (20 ... 14)","EMERGENCY STOP function":"Yes","Parameterizable Outputs":"Yes","Safety-Related Circuits":"Yes","Safety-Related 2-Channel":"1","Muting, 2 Sensor-Parallel":"No","Muting, 4 Sensor-Parallel":"No","Monitoring Parameterizable":"No","Position Switch Monitoring":"Yes","Protective Door Monitoring":"Yes","Evaluation: Enabling Switch":"Yes","Evaluation: Selector Switch":"Yes","Muting, 4 Sensor-Sequential":"No","Operating Frequency Maximum":"1 000 1/h","Operating Power Rated Value":"4.5 W","Proximity Switch Monitoring":"Yes","Substance Prohibitance (Date)":"07/01/2006","Type Of Electrical Connection":"screw-type terminals","Insulation Voltage Rated Value":"300 V","Monitoring Of Floating Sensors":"Yes","category according to EN 954-1":"4","EMERGENCY-OFF circuit monitoring":"Yes","Dark Period Of The Common Drivers":"1 ms","For Testing Contact-Based Sensors":"2","Number Of Function Blocks Typical":"300","Pressure-Sensitive Mat Monitoring":"Yes","Recovery Time Of The Safe Outputs":"420 ms","Control Supply Voltage Rated Value":"24 V","DC resistance of the cable maximum":"100 Ω","Monitoring Of Non-Floating Sensors":"Yes","air pressure according to SN 31205":"70 ... 106 kPa","Evaluation: Two-Hand Operator Panel":"Yes","Product Function Removable Terminal":"Yes","Surge Voltage Resistance Rated Value":"2 500 V","category according to EN ISO 13849-1":"4","two-hand control according to EN 574":"Yes","stop category according to EN 60204-1":"0 / 1","installation environment regarding EMC":"This product is suitable for Class A environments only. In household environments, this device can cause unwanted radio interference. The user is required to implement appropriate measures in this case.","Protective Door Monitoring With Tumbler":"No","due to burst according to IEC 61000-4-4":"2 kV (power ports) / 1 kV (signal ports)","reference code according to IEC 81346-2":"K","Finely Stranded With Core End Processing":"1x (0.5 ... 2.5 mm²), 2x (0.5 ... 1.5 mm²)","Input Delay Time At Digital Input Maximum":"150 ms","Touch Protection Against Electrical Shock":"finger-safe","product function suitable for AS-i Power24V":"No","protocol is supported AS-Interface protocol":"No","Opto-Electronic Protection Device Monitoring":"Yes","product function diagnostics with CTT2 slave":"No","hardware fault tolerance according to IEC 61508":"1","performance level (PL) according to ISO 13849-1":"e","vibration resistance according to IEC 60068-2-6":"5 ... 500 Hz: 0.75 mm","Ingress Aquisition Time At Digital Input Maximum":"60 ms","PFHD with high demand rate according to EN 62061":"0.000000007 1/h","SIL Claim Limit (subsystem) according to EN 62061":"Kat. 4 / SIL3 / Ple","Consumed Current For Rated Value Of Supply Voltage":"1.685 A","Evaluation: Electro-Sensitive Protective Equipment":"Yes","Mechanical Service Life (Switching Cycles) Typical":"10 000 000","electrostatic discharge according to IEC 61000-4-2":"4 kV contact discharge / 8 kV air discharge","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","protocol is supported ASIsafe (Safety at work) protocol":"No","Design Of The Contactless Switching Element Safety-Related":"P potential","Diagnostics Test Interval By Internal Test Function Maximum":"1 000 s","switching capacity current of semiconductor outputs at DC-13 at 24 V":"1.5 A","Connectable Conductor Cross-Section Finely Stranded With Core End Processing":"0.5 ... 2.5 mm²","Pulse Duration Of The Contactless Semiconductor Contact Block For Switching Off Safety-Related Maximum":"1 ms"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/76ff5ab3c002288a21c531bb1e7a1844.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=501945&mlfb=3RK3921-1AA10"},"ai":{"faq":[{"question":"Where can I buy 3RK3921-1AA10 and how do I get a price?","answer":"Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time — submit an RFQ for a firm price and lead time."},{"question":"What compliance documentation does Siemens provide for 3RK3921-1AA10?","answer":"The part carries IP20 enclosure protection and pollution degree 3. As a current-production SIRIUS component, standard Siemens declarations (CE, UKCA, RoHS, REACH) apply — consult the product documentation for specific certificates."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RK3921-1AA10","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/3RK3921-1AA10 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}}