{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RB3123-4PE0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RB3123-4PE0","canonicalUrl":"https://aoctrl.com/siemens/3RB3123-4PE0","factsUrl":"https://aoctrl.com/api/mcp/products/3RB3123-4PE0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS solid-state overload relay, size S0, 3RB3123-4PE0, adjustable trip classes 5E/10E/20E/30E, rated insulation 690 V, contactor mounting, spring-loaded terminals.","salesMarkdown":"The Siemens 3RB3123-4PE0 is a SIRIUS solid-state overload relay in size S0, designed to protect motors against overload and phase failure by monitoring motor current and tripping when the current exceeds the set threshold. The trip class is adjustable across CLASS 5E, 10E, 20E, and 30E, letting you match the relay's response to the motor's starting characteristics — a 5E setting trips fast for short-start loads like pumps, while a 30E setting gives longer starting room for high-inertia fans or conveyors. The relay mounts directly onto a contactor (contactor mounting), saving DIN-rail space in the panel. Rated insulation voltage is 690 V, and the main circuit uses spring-loaded terminals accepting 2x (0.25... 1.5 mm²) solid or stranded wire, with a single 10 mm² stranded option for the main circuit. The motor current setting is defined by upper and lower limits: the motor current must be greater than the lower current setting value, and less than the upper current setting value multiplied by 3.5. This means the relay can be adjusted to cover a wide motor current range within the S0 frame — typical for motors up to around 32 A full-load current depending on the setting range of the specific variant. The thermal current rating is 4 A for the signaling contact, which handles the trip-indication circuit. Operating temperature range is -25... +60 °C with temperature compensation across that span, so the relay maintains accurate trip timing even in a warm panel. Vibration resistance is 1-6 Hz at 15 mm amplitude and 6-500 Hz at 20 m/s² for 10 cycles, and shock resistance is 15g / 11 ms — adequate for most industrial machinery and conveyor applications. The relay includes a signaling contact rated at 24 V / 2 A, 120 V / 4 A, and 230 V / 3 A, among other voltage ratings, for remote trip indication. The note for message \"tripped\" is the standard SIRIUS diagnostic output — it closes when the relay has tripped, which can be wired to a PLC input or a panel lamp.","metaTitle":"Siemens 3RB3123-4PE0 SIRIUS Solid-State Overload Relay, S0,","metaDescription":"Siemens 3RB3123-4PE0 SIRIUS solid-state overload relay, size S0, adjustable trip classes 5E/10E/20E/30E. Rated insulation 690 V. Contactor mounting. Quoted to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Overload Relays"],"specifications":{"Note":"for message \"tripped\"","Depth":"85 mm","Solid":"2x (0.25 ... 1.5 mm²)","Width":"45 mm","title":"3RB3123-4PE0","Height":"109 mm","Maximum":"IMotor < upper current setting value x 3.5","Minimum":"IMotor > lower current setting value","at 24 V":"2 A","at 60 V":"0.55 A","Per Pole":"0.03 W","Stranded":"1x 10 mm²","at 110 V":"0.3 A","at 120 V":"4 A","at 125 V":"0.3 A","at 220 V":"0.11 A","at 230 V":"3 A","Trip Class":"CLASS 5E, 10E, 20E and 30E adjustable","Rated Value":"690 V","description":"Overload relay 1...4 A Electronic For motor protection Size S0, Class 5...30 Contactor mounting Main circuit: Spring-type terminal Auxiliary circuit: Spring-type terminal Manual-Automatic-Reset Internal ground fault detection","During Storage":"-40 ... +80 °C","Thermal Current":"4 A","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","During Transport":"-40 ... +80 °C","Fastening Method":"Contactor mounting","Shock Resistance":"15g / 11 ms","For Main Contacts":"M4","Mounting Position":"any","Solid Or Stranded":"2x (0,25 ... 1,5 mm²)","Product Brand Name":"SIRIUS","Product Designation":"solid-state overload relay","Vibration Resistance":"1-6 Hz, 15 mm; 6-500 Hz, 20 m/s²; 10 cycles","at 480 V rated value":"4 A","at 600 V rated value":"4 A","Size Of Overload Relay":"S0","For Main Current Circuit":"spring-loaded terminals","Temperature Compensation":"-25 ... +60 °C","Design Of Screwdriver Shaft":"Diameter 5 to 6 mm","Size Of The Screwdriver Tip":"Pozidriv PZ 2","according to IEC 60068-2-27":"15g / 11 ms; Signaling contact 97 / 98 in position \"Tripped\": 9g / 11 ms","at AC-3e rated value maximum":"690 V","Substance Prohibitance (Date)":"10/01/2009","Design Of The Auxiliary Switch":"integrated","Design Of The Overload Release":"electronic","Operating Frequency Rated Value":"50 ... 60 Hz","Operational Current Rated Value":"4 A","for AC motors at 500 V at 50 Hz":"0.37 ... 2.2 kW","for AC motors at 690 V at 50 Hz":"0.55 ... 3 kW","for remote-reset function at DC":"24 V","For Auxiliary And Control Circuit":"spring-loaded terminals","Between Main And Auxiliary Circuit":"690 V","Relative Humidity During Operation":"10 ... 95 %","With Type Of Assignment 2 Required":"gG: 20 A","Display Version For Switching Status":"Slide switch","Surge Voltage Resistance Rated Value":"6 kV","With Type Of Coordination 1 Required":"gG: 35 A, RK5: 15 A","for 3-phase motors at 400 V at 50 Hz":"0.37 ... 1.5 kW","for AWG cables for auxiliary contacts":"1x (24 ... 16), 2x (24 ... 16)","Between Auxiliary And Auxiliary Circuit":"300 V","due to burst according to IEC 61000-4-4":"2 kV (power ports), 1 kV (signal ports) corresponds to degree of severity 3","reference code according to IEC 81346-2":"F","Finely Stranded With Core End Processing":"2x (0.25 ... 1.5 mm²)","Number Of Poles For Main Current Circuit":"3","Finely Stranded Without Core End Processing":"2x (0.25 ... 1.5 mm²)","number of CO contacts for auxiliary contacts":"0","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","operational current at AC-3e at 400 V rated value":"4 A","Size Of Contactor Can Be Combined Company-Specific":"S0","electrostatic discharge according to IEC 61000-4-2":"6 kV contact discharge / 8 kV air discharge","Type Of Voltage Supply Via Input/Output Link Master":"No","contact rating of auxiliary contacts according to UL":"B600 / R300","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","Response Time Of The Grounding Protection In Settled State":"1 000 ms","Response Value Current Of The Grounding Protection Minimum":"0.75 x IMotor","Arrangement Of Electrical Connectors For Main Current Circuit":"Top and bottom","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gG: 6 A","insulation voltage with degree of pollution 3 at AC rated value":"690 V","Product Component Removable Terminal For Auxiliary And Control Circuit":"Yes","power loss [W] for rated value of the current at AC in hot operating state":"0.1 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"1 ... 4 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/fb3cb7f41d3ac64b855efc89ff739496.pdf","sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=184477&mlfb=3RB3123-4PE0"},"ai":{"faq":[{"question":"What is the trip class adjustment range on the 3RB3123-4PE0?","answer":"The trip class is adjustable to CLASS 5E, 10E, 20E, or 30E, letting you match the relay's response to the motor's starting characteristics."},{"question":"How is the 3RB3123-4PE0 mounted in a panel?","answer":"It uses contactor mounting — it snaps directly onto a compatible SIRIUS contactor, saving DIN-rail space."},{"question":"Where can I buy the 3RB3123-4PE0 and how is it quoted?","answer":"This part is sourced through independent distribution and quoted to order against an RFQ. Availability and current pricing are confirmed at quote time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RB3123-4PE0","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/3RB3123-4PE0 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}}