{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"6ES7921-5AH20-0AA0","brand":"Siemens","brandSlug":"siemens","productSlug":"6ES7921-5AH20-0AA0","canonicalUrl":"https://aoctrl.com/siemens/6ES7921-5AH20-0AA0","factsUrl":"https://aoctrl.com/api/mcp/products/6ES7921-5AH20-0AA0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIMATIC S7-1500 front connector module, 40-pole, 24 V rated, 1 A, push-in terminals, direct mounting.","salesMarkdown":"The Siemens 6ES7921-5AH20-0AA0 is a front connector module purpose-built for the SIMATIC S7-1500 system, designed to terminate field wiring to digital I/O modules. It provides 40 poles across the front connector, with 8 terminals arranged as 4 x 1 x L+ and 4 x 1 x M for the power supply, plus a 16-pole IDC connector for the connection cable. This is the wiring interface between the I/O module and the field devices — not the module itself, but the plug-in termination point that carries the 24 V rated supply and signal currents up to 1 A per contact. Rated at 24 V DC and 1 A per contact, this connector handles the typical load of S7-1500 digital inputs and outputs — solenoids, indicator lamps, and small relays — without exceeding the contact rating. The total current limit is 2 A for horizontal mounting positions, so if you're populating adjacent terminals near their 1 A limit, the horizontal derating caps the aggregate. Stranded conductors from 0.5 to 1.5 mm² are accepted, with a stripped length of 8 mm. The 40-pole count means this connector mates with a standard S7-1500 digital I/O module's front interface. The 8 terminals dedicated to power supply (4 x L+, 4 x M) allow daisy-chaining supply to multiple modules through the connector itself, reducing point-to-point wiring. Maximum cable length between this front connector module and the terminal module is 30 m, which covers most cabinet layouts but is worth checking if your panel has a remote I/O drop.","metaTitle":"Siemens 6ES7921-5AH20-0AA0 Front Connector Module for S7-150","metaDescription":"Siemens 6ES7921-5AH20-0AA0 front connector module for SIMATIC S7-1500 digital I/O. Rated 24 V, 1 A per contact, push-in terminals. Mature lifecycle, sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["PLC Accessories"],"specifications":{"title":"6ES7921-5AH20-0AA0","Stranded":"0.5 ... 1.5 mm²","Rated Value":"24 V","description":"Front connector module with 4x16 pole IDC connector for digital 32 I/O modules of the S7-1500 Potential supply over Push-in terminal","Mounting Type":"direct mounting","Target System":"SIMATIC S7-1500","During Storage":"-40 ... +70 °C","Number Of Poles":"40; of the front connector","Stripped Length":"8 mm","at DC / maximum":"60 V","lifecycle_stage":"mature","During Operation":"0 ... 60 °C","Degree Of Pollution":"2","Number Of Terminals":"8; 4 x 1 x L+, 4 x 1 x M","Product Designation":"Front connector module","Suitability For Use":"Digital I/O modules","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":"2 A; for mounting position horizontal","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":"0.5 ... 1.5 mm²","Product Component / Required / End Cover Plate":"No","with plastic sleeve / according to DIN 46228-4":"Length 8mm to 9mm","Type Of Electrical Connection / For Power Supply":"Push-In terminal","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 46228/1 or DIN 46228/4 with plastic collar max. 0.75 mm2","without plastic sleeve / according to DIN 46228-1":"Length 8mm to 9mm","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":"4"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$45.72","stockQuantity":0,"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=350479&mlfb=6ES7921-5AH20-0AA0"},"ai":{"faq":[{"question":"What is the stranded conductor range this connector accepts?","answer":"It accepts stranded conductors from 0.5 to 1.5 mm². Finely stranded wire with core-end processing ranges from 0.25 to 1.5 mm², and without processing from 0.5 to 1.5 mm². The stripped length is 8 mm."},{"question":"What is the rated voltage and current for this front connector?","answer":"Rated voltage is 24 V DC, with a maximum of 60 V DC. Rated current is 1 A per contact, with a total current maximum of 2 A for horizontal mounting positions."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/6ES7921-5AH20-0AA0","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/6ES7921-5AH20-0AA0 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}}