{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RT1916-2FJ21","brand":"Siemens","brandSlug":"siemens","productSlug":"3RT1916-2FJ21","canonicalUrl":"https://aoctrl.com/siemens/3RT1916-2FJ21","factsUrl":"https://aoctrl.com/api/mcp/products/3RT1916-2FJ21","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary switch, 3RT1916-2FJ21, 3 A maximum, clip-on mounting, 75 mm depth, 45 mm width.","salesMarkdown":"It's the part you add when the main contactor's built-in auxiliary contacts are already used up, or when you need a normally-open / normally-closed combination the base unit doesn't offer. Rated for a maximum switching current of 3 A, it handles 1 A at 24 V DC, 0.2 A at 125 V DC, and 0.1 A at 250 V DC — these are the numbers that govern whether it reliably breaks a PLC input or a small relay coil without welding contacts. The adjustable time-delay range of 0.5 to 10 s (with a 150 ms recovery time and a 200 ms minimum ON period) means this variant includes an onboard timer for sequenced start or delayed dropout — not every auxiliary switch in the SIRIUS family carries that. Clip-on fastening means it snaps directly onto the front or side of a SIRIUS contactor without tools — no DIN-rail footprint consumed beyond the base unit itself. Wire termination accepts solid or stranded conductors from 18 to 14 AWG (2x 20...14 AWG solid), so it fits standard control wiring without pigtails or ferrule adapters.","metaTitle":"Siemens 3RT1916-2FJ21 SIRIUS Auxiliary Switch, 3 A","metaDescription":"Siemens 3RT1916-2FJ21 SIRIUS auxiliary switch, 3 A max, clip-on mount, 75 mm depth. Current production. Sourced to order. RFQ for lead time.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"75 mm","Solid":"18 ... 14","Width":"45 mm","Height":"38 mm","Maximum":"3 A","Upwards":"0 m","at 24 V":"1 A","Forwards":"0 m","ON-delay":"No","Stranded":"18 ... 14","at 125 V":"0.2 A","at 250 V":"0.1 A","Backwards":"0 m","Downwards":"0 m","OFF delay":"No","At The Side":"0 m","Non-Volatile":"No","Initial Value":"0.85","Pulse Delayed":"No","Pulse-Shaping":"No","Recovery Time":"150 ms","During Storage":"-40 ... +85 °C","Adjustable Time":"0.5 ... 10 s","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","During Transport":"-40 ... +85 °C","Fastening Method":"clip-on","Full-Scale Value":"1.1","Delayed Switching":"0","Mounting Position":"any","additive ON-delay":"No","at DC rated value":"24 V","minimum ON period":"200 ms","ON-delay/OFF-delay":"No","Product Brand Name":"SIRIUS","Star-Delta Circuit":"No","Type Of Insulation":"Basic insulation","Degree Of Pollution":"3","Product Designation":"auxiliary switch","at AWG cables solid":"2x (20 ... 14)","Passing Make Contact":"No","at 50 Hz rated value":"24 V","at 60 Hz rated value":"24 V","Instantaneous Contact":"0","Passing Break Contact":"No","at AWG cables stranded":"2x (20 ... 14)","OFF delay/instantaneous":"No","Relative Repeat Accuracy":"1 %","Pulse Delayed/Instantaneous":"No","Pulse-Shaping/Instantaneous":"No","Substance Prohibitance (Date)":"01.07.2006 00:00:00","Design Of The Surge Suppressor":"with varistor","ON-delay/instantaneous contact":"No","additive ON-delay/instantaneous":"No","EMC immunity acc. to IEC 61812-1":"EN 61000-6-2","ON-delay/OFF-delay/instantaneous":"No","Variably Clocked With Pulse Start":"No","Control Supply Voltage Frequency 1":"50 ... 60 Hz","Relative Humidity During Operation":"15 ... 95 %","Star-Delta Circuit With Delay Time":"No","due to burst acc. to IEC 61000-4-4":"2 kV network connection / 1 kV control connection","reference code acc. to IEC 81346-2":"K","Passing Break Contact/Instantaneous":"No","Product Function Star-Delta Circuit":"No","protection class IP of the terminal":"IP20","Surge Voltage Resistance Rated Value":"4 000 V","Variably Clocked With Interval Start":"No","Constant Clock Cycle With Pulse Start":"No","Flashing Symmetrically With Pulse Start":"No","Product Component Semi-Conductor Output":"No","shock resistance acc. to IEC 60068-2-27":"11g / 15 ms","Constant Clock Cycle With Interval Start":"No","Finely Stranded With Core End Processing":"0.5 ... 2.5 m²","Flashing Asymmetrically With Pulse Start":"No","Product Extension Optional Remote Control":"No","Product Extension Required Remote Control":"No","Flashing Symmetrically With Interval Start":"No","Passing Make Contact/Instantaneous Contact":"No","vibration resistance acc. to IEC 60068-2-6":"10 ... 55 Hz: 0.35 mm","Design Of The Control Terminal Non-Floating":"No","Flashing Asymmetrically With Interval Start":"No","Retriggerable With Deactivated Control Signal":"No","Type Of Voltage Of The Control Supply Voltage":"AC/DC","electrostatic discharge acc. to IEC 61000-4-2":"4 kV contact discharge / 8 kV air discharge","field-based interference acc. to IEC 61000-4-3":"10 V/m","Retrotriggerable With Switched-On Control Signal":"No","Mechanical Service Life (Switching Cycles) Typical":"10 000 000","Size Of Contactor Can Be Combined Company-Specific":"S00","due to conductor-earth surge acc. to IEC 61000-4-5":"2 kV","protection class IP on the front acc. to IEC 60529":"IP20","At The Relay Outputs Switchover Delayed/Without Delay":"No","Flashing Symmetrically With Pulse Start/Instantaneous":"No","Relative Setting Accuracy Relating To Full-Scale Value":"15 %","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Flashing Symmetrically With Interval Start/Instantaneous":"No","Type Of Electrical Connection For Auxiliary And Control Circuit":"screw-type terminals","Product Component Removable Terminal For Auxiliary And Control Circuit":"No","Retrotriggerable With Deactivated Control Signal/Instantaneous Contact":"No","Retrotriggerable With Switched-On Control Signal/Instantaneous Contact":"No","Design Of The Fuse Link For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 4 A"}},"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=314207&mlfb=3RT1916-2FJ21","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RT1916-2FJ21/alternatives.json"},"ai":{"faq":[{"question":"What are the key switching ratings for this auxiliary switch?","answer":"Maximum switching current is 3 A. At 24 V DC it switches 1 A, at 125 V DC it switches 0.2 A, and at 250 V DC it switches 0.1 A. These are the values that determine whether the contacts hold up under your specific load."},{"question":"Does this auxiliary switch include an adjustable time delay?","answer":"Yes, it has an adjustable ON-delay or OFF-delay range of 0.5 to 10 s, with a 150 ms recovery time and a 200 ms minimum ON period. Not all SIRIUS auxiliary switches include a timer function."},{"question":"What wire sizes does the 3RT1916-2FJ21 accept?","answer":"It accepts solid or stranded conductors from 18 to 14 AWG, and up to 2x 20...14 AWG solid. No special ferrules or adapters are required for standard control wiring."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RT1916-2FJ21","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/3RT1916-2FJ21 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}}