{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7921-3AC00-0AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7921-3AC00-0AA0","canonicalUrl":"https://aoctrl.com/siemens/6ES7921-3AC00-0AA0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7921-3AC00-0AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC S7-300 front connector module, 6ES7921-3AC00-0AA0, 20-pole, spring clamp power supply, 60 V rated, 1 A rated, for 2A output modules.","salesMarkdown":"The Siemens 6ES7921-3AC00-0AA0 is a front connector module designed for the SIMATIC S7-300 system, specifically for use with 2A digital output modules. It provides the physical and electrical interface between the output module and field wiring via a 20-pole front connector and a flat ribbon cable connection. Rated at 60 V DC and 1 A per channel, with a total current capacity of 4 A across all channels, this module handles the power distribution for the output bank. The 24 V DC rated supply for the logic side is typical for S7-300 backplane power. Mounting is direct to the S7-300 rail or panel, with the terminal block positioned at the top for easy access during wiring. The spring-clamp connection for the power supply accepts stranded wire from 0.25 to 1.5 mm², stripped to 6 mm. ## Wiring and connection details The module uses a 16-pole IDC connector for the flat ribbon cable to the output module, and four spring-clamp terminals (2 x L+, 2 x M) for the 24 V DC power supply feed. Up to two wires per connection are allowed, with a maximum outer insulation diameter of 3.1 mm for the supply terminals. For flexible conductors with core-end processing, use ferruled ends per DIN 46228 without plastic collar, ferrule length 5 to 7 mm. Without ferrule, the same 0.25 to 1.5 mm² range applies. Solid conductors are not supported — stranded or finely stranded only. Maximum wire length between the front connector module and the terminal module is 30 m. The recommended screwdriver blade width for the spring-clamp actuation is 3.5 mm. It is not a new introduction nor flagged for phase-out — it remains a standard, orderable line item for S7-300 system builds and spares.","metaTitle":"Siemens 6ES7921-3AC00-0AA0 Front Connector Module, 20-pole,","metaDescription":"Siemens 6ES7921-3AC00-0AA0 front connector module for SIMATIC S7-300 2A output modules. 20-pole, spring clamp power supply, 60 V rated, 1 A rated. Mature lifecycle, available to or","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["PLC Accessories"],"specifications":{"Stranded":"0.25 ... 1.5 mm²","Rated Value":"60 V","Mounting Type":"direct mounting","Target System":"SIMATIC S7-300","During Storage":"-40 ... +70 °C","Number Of Poles":"20; of the front connector","Stripped Length":"6 mm","at DC / maximum":"60 V","lifecycle_stage":"mature","During Operation":"0 ... 60 °C","Degree Of Pollution":"2","Number Of Terminals":"4; 2 x 1 x L+, 2 x 1 x M","Product Designation":"Front connector module","Suitability For Use":"2A Output module","at DC / rated value":"24 V","Overvoltage Category":"2","Current / Rated Value":"1 A","Operating Temperature":"0 ... 60 °C","Wire Length / Maximum":"30 m; between front connector module and terminal module","Total Current / Maximum":"4 A","Color / Of The Enclosure":"black","Position / Of The Terminal":"at the top","Width Of Screwdriver Blade":"3.5 mm","Product Feature / Transparent":"No","Material / Of The Insulating Body":"other","Number Of Cables / Per Connection":"2; Connection for internal system: Combination of 1 or 2 Wires until the sum total of cross sections be achieved in a ferrule.","Number Of Poles / At The 1st Interface":"16; the IDC connector for the connection cable","Outer Diameter / Of The Wire Insulation":"3.1 mm; to the connection of the supply terminal","reference code / according to IEC 81346-2":"XG","Finely Stranded / With Core End Processing":"0.25 ... 1.5 mm²","Finely Stranded / Without Core End Processing":"0.25 ... 1.5 mm²","Product Component / Required / End Cover Plate":"No","Type Of Electrical Connection / For Power Supply":"Spring clamp","design tested acc. to type of protection / EEx e":"No","For Flexible Conductor / With Core End Processing":"0.25 ... 1.5 mm²; End sleeve according to DIN 46228 without plastic collar","without plastic sleeve / according to DIN 46228-1":"Length 5mm to 7mm","Type Of Connectable Conductor Cross-Sections / Solid":"No","Type Of Electrical Connection / For Connecting Cable":"Plug-in connection","Number Of The Plug Contacts / Of The Electrical Connection":"1"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$52.07 – $99.00","priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/6d57f154fff616166253fab8c566f5cb.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=532478&mlfb=6ES7921-3AC00-0AA0","alternativesUrl":"https://aoctrl.com/api/mcp/products/6ES7921-3AC00-0AA0/alternatives.json"},"ai":{"faq":[{"question":"What wire sizes does 6ES7921-3AC00-0AA0 accept?","answer":"It accepts stranded wire from 0.25 to 1.5 mm², with a stripped length of 6 mm. For flexible conductors, use ferrules per DIN 46228 without plastic collar, 5 to 7 mm long. Solid conductors are not supported."},{"question":"What is the rated voltage and current for this front connector module?","answer":"Rated voltage is 60 V DC, with a rated current of 1 A per channel and a total current maximum of 4 A across all channels. The logic supply is rated at 24 V DC."},{"question":"Will 6ES7921-3AC00-0AA0 work with a 2A output module?","answer":"Yes, it is specifically designated for use with 2A digital output modules in the SIMATIC S7-300 system, connecting via a 16-pole IDC ribbon cable."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7921-3AC00-0AA0","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/6ES7921-3AC00-0AA0 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}}