{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RA6120-2CB33","brand":"Siemens","brandSlug":"siemens","productSlug":"3RA6120-2CB33","canonicalUrl":"https://aoctrl.com/siemens/3RA6120-2CB33","factsUrl":"https://aoctrl.com/api/mcp/products/3RA6120-2CB33","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS compact starter, 3RA6120-2CB33, direct starter design, 24 V AC/DC control, 53 kA breaking capacity at 400 V, adjustable trip class 10/20.","salesMarkdown":"## Compact starter for motor branch circuits The Siemens 3RA6120-2CB33 is a SIRIUS compact starter combining a contactor and overload relay in a single 45 mm-wide package. It is a direct starter design rated for continuous operation per IEC 60947-6-2, meaning it handles sustained motor loads without derating for duty cycle. Control voltage is 24 V AC/DC, so it integrates cleanly into a 24 VDC control bus without an additional power supply tap. The coil draws 2.8 W AC or 2.9 W DC at maximum — low enough that a standard 24 VDC power supply can drive several of these in a panel without exceeding the supply budget. ## Trip class and motor protection Trip class is adjustable between Class 10 and Class 20. Class 20 allows 20 seconds at 7.2×, covering high-inertia loads like conveyors or centrifuges that need a longer start curve. The adjustability means one SKU covers both duty types. Rated operational current at 480 V is 4 A, and at 600 V it is also 4 A. This is the continuous current the main contacts carry in AC-3 motor-switching duty. The 1 500 W rating at 400 V gives a quick power-based sizing check for 400 V line-fed motors. The 45 mm width and 165 mm depth fit standard 200 mm-deep enclosures, leaving room for wiring ducts and other components. Any mounting position is permitted, so panel layout is flexible. Wire termination accepts 2x (0.25 to 1.5 mm²) solid or stranded conductors. The main circuit uses plug-in terminals without screw clamps, which speeds replacement — pull the old unit, plug in the new one, no re-torquing. Two status LEDs give local indication of operating state and fault conditions, useful during commissioning and troubleshooting without needing a multimeter or HMI connection. Vibration resistance covers 4 to 5.8 Hz at 15 mm amplitude and 5.8 to 500 Hz at 20 m/s² for 10 cycles. Shock resistance is 60 m/s² (6g) for 10 ms, three shocks per axis. This is suitable for installation on machinery with moderate vibration, like conveyor drives or pump skids.","metaTitle":"Siemens 3RA6120-2CB33 SIRIUS Compact Starter, 24 VDC, 53 kA","metaDescription":"Siemens 3RA6120-2CB33 SIRIUS compact starter, 24 VDC control, 53 kA breaking capacity at 400 V. Adjustable Class 10/20. Active production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Motor Starters"],"specifications":{"Depth":"165 mm","Solid":"2x (0.25 ... 1.5 mm²)","Width":"45 mm","at DC":"24 ... 24 V","title":"3RA6120-2CB33","Height":"191 mm","at 400 V":"53 kA","at 50 Hz":"24 ... 24 V","at 60 Hz":"24 V","Trip Class":"CLASS 10 and 20 adjustable","Recommended":"vertical, on horizontal standard DIN rail","description":"SIRIUS Compact load feeder DOL starter 690 V 24 V AC/DC 50...60 Hz 1...4 A IP20 Connection main circuit: plug-in, without terminals Connection auxiliary circuit: Spring-type terminal","1 Rated Value":"50 Hz","2 Rated Value":"60 Hz","at AC maximum":"2.8 W","at DC maximum":"2.9 W","During Storage":"-55 ... +80 °C","number of LEDs":"2","Type Of Voltage":"AC/DC","lifecycle_stage":"current","During Operation":"-20 ... +60 °C","During Transport":"-55 ... +80 °C","Fastening Method":"screw and snap-on mounting","IO-Link protocol":"No","Shock Resistance":"a=60 m/s2 (6g) with 10 ms per 3 shocks in all axes","Mounting Position":"any","at DC rated value":"24 V","Product Brand Name":"SIRIUS","Type Of Assignment":"continous operation according to IEC 60947-6-2","Degree Of Pollution":"3","Product Designation":"compact starter","Vibration Resistance":"f= 4 ... 5.8 Hz, d= 15 mm; f= 5.8 ... 500 Hz, a= 20 m/s²; 10 cycles","at 400 V rated value":"1 500 W","at 480 V rated value":"4 A","at 50 Hz rated value":"24 V","at 500 V rated value":"3 kA","at 60 Hz rated value":"24 V","at 600 V rated value":"4 A","at 690 V rated value":"3 kA","AS-Interface protocol":"No","Design Of The Product":"direct starter","For Main Current Circuit":"plug-in without terminals","at 200/208 V rated value":"0.75 hp","at 220/230 V rated value":"0.75 hp","at 460/480 V rated value":"2 hp","at 575/600 V rated value":"3 hp","at AC at 400 V rated value":"4 A","NO-Load Switching Frequency":"3 600 1/h","Of The Main Contacts Typical":"10 000 000","at AC in hot operating state":"1 W","at AC-3 at 400 V rated value":"1.5 kW","Of Auxiliary Contacts Typical":"10 000 000","Substance Prohibitance (Date)":"05/01/2012","Insulation Voltage Rated Value":"690 V","at DC-13 at 6 A at 24 V typical":"30 000","at AC-15 at 6 A at 230 V typical":"200 000","degree of protection NEMA rating":"other","For Auxiliary And Control Circuit":"spring-loaded terminals","Of The Signaling Contacts Typical":"10 000 000","Between Main And Auxiliary Circuit":"400 V","Design Of Short-Circuit Protection":"electromagnetic","Product Extension Auxiliary Switch":"Yes","Product Function Bus Communication":"No","Relative Humidity During Operation":"10 ... 90 %","Without Load Current Share Typical":"2.9 W","Surge Voltage Resistance Rated Value":"6 000 V","at AWG cables for auxiliary contacts":"2x (24 ... 16)","Between Control And Auxiliary Circuit":"300 V","at AC in hot operating state per pole":"0.33 W","Between Auxiliary And Auxiliary Circuit":"250 V","due to burst according to IEC 61000-4-4":"4 kV main contacts, 2 kV auxiliary contacts","reference code according to IEC 81346-2":"Q","Finely Stranded With Core End Processing":"2x (0.25 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","Formula For Making Capacity Limit Current":"12 x Ie","Product Function Short Circuit Protection":"Yes","Supply voltage required Auxiliary voltage":"No","with low demand rate according to SN 31920":"40 %","Finely Stranded Without Core End Processing":"2x (0.25 ... 1.5 mm²)","Formula For Limit Current Breaking Capacity":"10 x Ie","at AC-41 according to IEC 60947-6-2 maximum":"750 1/h","at AC-43 according to IEC 60947-6-2 maximum":"250 1/h","with high demand rate according to SN 31920":"50 %","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","operating voltage at AC-3 rated value maximum":"690 V","electrostatic discharge according to IEC 61000-4-2":"8 kV","contact rating of auxiliary contacts according to UL":"contacts 21-22, 13-14, 43-44 Q600 / A600, contacts 77-78 R300 / B300, contacts 95-96-98 R300 / D300","Product Component Removable Terminal For Main Circuit":"Yes","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","product function control circuit interface with IO link":"No","conducted HF interference emissions according to CISPR11":"150 kHz ... 30 MHz Class A","field-bound HF interference emission according to CISPR11":"30 ... 1000 MHz Class A","operational current of auxiliary contacts at AC-12 maximum":"10 A","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 10 A","Product Function Control Circuit Interface To Parallel Wiring":"Yes","Product Component Removable Terminal For Auxiliary And Control Circuit":"Yes","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"1 ... 4 A","number of NO contacts of instantaneous short-circuit trip unit for signaling contact":"1","For Short-Circuit Protection Of The Signaling Switch Of The Overload Release Required":"4A gL/gG/400V","number of CO contacts of the current-dependent overload release for signaling contact":"1","For Short-Circuit Protection Of The Signaling Switch Of The Short-Circuit Release Required":"6A gL/gG/400V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$255.27","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/618f601cdfb94bf8b7d3eea5d563071e.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=255244&mlfb=3RA6120-2CB33"},"ai":{"faq":[{"question":"Is 3RA6120-2CB33 suitable for reversing applications?","answer":"No, this is a direct starter design, not a reversing starter. For reversing duty you would need two compact starters or a dedicated reversing assembly. The 3RA6120-2CB33 provides forward-only motor starting and overload protection in one unit."},{"question":"What is the difference between 3RA6120-2CB33 and 3RA6120-2CB32?","answer":"The primary difference is the control voltage. The 3RA6120-2CB33 uses 24 V AC/DC control, while the 3RA6120-2CB32 uses a different control voltage. Both are SIRIUS compact starters with the same 45 mm width and 53 kA breaking capacity at 400 V, but the control circuit voltage differs, so verify your control bus voltage before ordering."},{"question":"Where can I buy Siemens 3RA6120-2CB33 online?","answer":"The Siemens 3RA6120-2CB33 is available to order through independent industrial automation distributors. Submit an RFQ to confirm current pricing and availability — the part is sourced to order and quoted on request, with lead time confirmed at quote time."},{"question":"What are the specifications of 3RA6120-2CB33?","answer":"Key specifications: SIRIUS compact starter, direct starter design, 24 V AC/DC control, 53 kA breaking capacity at 400 V, adjustable trip class 10/20, 45 mm width, 165 mm depth, 191 mm height, 2 status LEDs, operating temperature -20 to +60 °C, pollution degree 3, mounts on 35 mm DIN rail."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RA6120-2CB33","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/3RA6120-2CB33 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T19:47:38.189Z","lastPublished":"2026-07-22T19:47:38.189Z","indexable":true}}