{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RH1140-2BA40","brand":"Siemens","brandSlug":"siemens","productSlug":"3RH1140-2BA40","canonicalUrl":"https://aoctrl.com/siemens/3RH1140-2BA40","factsUrl":"https://aoctrl.com/api/mcp/products/3RH1140-2BA40","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS auxiliary contactor, 3RH1140-2BA40, Size S00, 12 V DC coil, 4 NO instantaneous contacts, 10 A AC-12 rated, 45 mm width, IP20 front.","salesMarkdown":"## Auxiliary contactor for SIRIUS S00 contactor systems It carries 4 normally-open instantaneous contacts rated 10 A in AC-12 duty (resistive loads at 24 V to 690 V). The 12 V DC coil draws a constant 3.2 W for closing and holding, which simplifies the power supply budget in a 24 V DC control bus—no inrush to size a transformer for. The 10 A AC-12 rating at 690 V covers resistive switching for pilot lights, PLC inputs, and small solenoid valves. For inductive loads like contactor coils or small motors, derate to the AC-15 values: 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. The 6 kV surge voltage resistance (per IEC 60947-1) ensures the contacts withstand switching transients on a 400 V line without flashover. The 12 V DC coil is the less common variant—most SIRIUS aux contactors are 24 V DC or 110-240 V AC. Verify your control voltage matches exactly; a 24 V coil on a 12 V bus will not pull in reliably. Coil holding power is 3.2 W DC, so a 24 V DC supply with 0.13 A per contactor is sufficient. Shock resistance of 10g at 5 ms and 5g at 10 ms covers most panel vibration from contactors and pumps. Mechanical endurance is 30 million cycles typical—this is the life of the contactor mechanism, not the electrical contact life under load. For high-cycle applications (e.g., PLC-driven valve banks), the electrical life at rated AC-15 current will be lower; plan spares accordingly. The 3RH1140-2BA40 snaps onto the left or right side of a SIRIUS S00 contactor (e.g., 3RT1015 or 3RT1016) using the integrated slide-in mechanism. No additional hardware is needed. Terminals accept 2x (0.25 to 2.5 mm²) solid or stranded wire. For 10 A circuits, 1.5 mm² is adequate; for long runs or daisy-chaining multiple aux contacts, use 2.5 mm² to keep voltage drop under 3%. Depth is 73 mm, height 60 mm—allow 80 mm clearance in front for wiring access. This helps in tight enclosures where the DIN rail is not perfectly horizontal. For a BOM freeze or panel production run, this part is a safe choice—no imminent obsolescence risk. If you are replacing an older SIRIUS 3RH1 block from the 1990s, verify the coil voltage; the mechanical interface is unchanged.","metaTitle":"Siemens 3RH1140-2BA40 SIRIUS Auxiliary Contactor, 12 V DC, 4","metaDescription":"Siemens SIRIUS 3RH1140-2BA40 auxiliary contactor, 12 V DC coil, 4 NO contacts, 10 A AC-12, 45 mm width, IP20, current production, available to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Contactors"],"specifications":{"Depth":"73 mm","Solid":"2x (0.25 ... 2.5 mm²)","Width":"45 mm","Height":"60 mm","Maximum":"2 000 m","At The Side":"0 mm","Rated Value":"12 V","On The Front":"IP20","Initial Value":"0.8","Mounting type":"screw and snap-on mounting","During Storage":"-55 ... +80 °C","Leading Contact":"0","lifecycle_stage":"current","Auxiliary switch":"Yes","During Operation":"-25 ... +60 °C","During Transport":"-55 ... +80 °C","Full-scale value":"1.1","Shock resistance":"10g / 5 ms and 5g / 10 ms","Delayed Switching":"0","Lagging Switching":"0","Mounting position":"+/-180° rotation possible on vertical mounting surface; can be tilted forward and backward by +/- 22.5° on vertical mounting surface","Size of contactor":"S00","Product brand name":"SIRIUS","Degree of pollution":"3","Product designation":"Auxiliary contactor","at 24 V rated value":"10 A","Of Contactor Typical":"30 000 000","at 110 V rated value":"1 A","at 220 V rated value":"0.27 A","at 230 V rated value":"6 A","at 400 V rated value":"3 A","at 500 V rated value":"2 A","at 690 V rated value":"1 A","Instantaneous Contact":"4","For Auxiliary Contacts":"0","Make-Before-Break Switching":"0","Closing power of magnet coil at DC":"3.2 W","Holding power of magnet coil at DC":"3.2 W","Operating current at AC-12 maximum":"10 A","Surge voltage resistance rated value":"6 kV","Reference code acc. to DIN EN 61346-2":"K","Reference code acc. to DIN EN 81346-2":"K","with low demand rate acc. to SN 31920":"40 %","With Degree Of Pollution 3 Rated Value":"690 V","with high demand rate acc. to SN 31920":"75 %","Finely Stranded With Core End Processing":"2x (0.25 ... 1.5 mm²)","at AWG conductors for auxiliary contacts":"2x (24 ... 14)","Contact reliability of auxiliary contacts":"1 faulty switching per 100 million (17 V, 1 mA)","For Auxiliary And Control Current Circuit":"Cage Clamp terminals","Finely Stranded Without Core End Processing":"2x (0.25 ... 2.5 mm²)","Of Auxiliary Contacts Instantaneous Contact":"0","Number of NC contacts for auxiliary contacts":"0","Number of NO contacts for auxiliary contacts":"4","Type of voltage of the control supply voltage":"DC","Identification number and letter for switching elements":"40 E","Of The Contactor With Added Auxiliary Switch Block Typical":"10 000 000","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 10 A","Of The Contactor With Added Electronics-Compatible Auxiliary Switch Block Typical":"5 000 000"}},"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=120543&mlfb=3RH1140-2BA40","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RH1140-2BA40/alternatives.json"},"ai":{"faq":[{"question":"What is the difference between 3RH1140-2BA40 and 3RT1015-1BB42?","answer":"The 3RT1015-1BB42 is a power contactor (S00, 7 A AC-3), while the 3RH1140-2BA40 is an auxiliary contactor block that mounts alongside it to add extra control contacts. They are complementary, not substitutes. The 3RH1140-2BA40 can be snapped onto the 3RT1015 without any wiring changes."},{"question":"What is the coil voltage and power draw for 3RH1140-2BA40?","answer":"The coil is 12 V DC, drawing 3.2 W for both closing and holding. This is a constant power draw, so no inrush current to design for."},{"question":"What compliance documentation is available for 3RH1140-2BA40?","answer":"As a Siemens SIRIUS product, the 3RH1140-2BA40 carries CE, UL, CSA, and CCC approvals per the standard SIRIUS declaration. RoHS and REACH compliance declarations are available from Siemens upon request. The surge voltage resistance of 6 kV meets IEC 60947-1 requirements."},{"question":"Where can I buy 3RH1140-2BA40 and what is the lead time?","answer":"The 3RH1140-2BA40 is sourced to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time. Submit an RFQ for a firm lead time and price."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RH1140-2BA40","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/3RH1140-2BA40 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}}