{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RB2123-4PD0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RB2123-4PD0","canonicalUrl":"https://aoctrl.com/siemens/3RB2123-4PD0","factsUrl":"https://aoctrl.com/api/mcp/products/3RB2123-4PD0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS solid-state overload relay, 3RB2123-4PD0, adjustable trip class 5E/10E/20E/30E, contactor-mount, ATEX Ex II (2) GD, 3-pole, screw-type main terminals, spring-loaded auxiliary terminals.","salesMarkdown":"## Solid-state overload relay with adjustable trip class The Siemens 3RB2123-4PD0 is a SIRIUS solid-state overload relay for three-phase motor protection. Trip class is field-adjustable among CLASS 5E, 10E, 20E, and 30E — so you match the thermal curve to the motor start profile: fast for submersible pumps, slow for high-inertia fans. Mounts directly to a contactor (fastening method: contactor mounting), saving panel width compared to a separate base. ## ATEX and environmental ratings ATEX certification PTB 06 ATEX 3001 Ex II (2) GD. Operating temperature range -25 to +60 °C, storage/transport -40 to +80 °C, 100 % relative humidity during operation. Shock resistance 15g / 11 ms; mounting position any. Main current circuit uses screw-type terminals accepting 2x (0.25... 1.5 mm²) solid or 2x (14... 10) AWG. Auxiliary and control circuit uses spring-loaded terminals for faster wiring — 2x (0.25... 1.5 mm²) finely stranded with ferrule, or 2x (24... 16) AWG. Surge voltage resistance rated 6 kV; burst immunity 2 kV on power ports, 1 kV on signal ports per IEC 61000-4-4 severity 3. Listed as current-production lifecycle stage. Substance prohibitance date 07/01/2006 aligns with RoHS compliance. No auxiliary CO contacts on this variant — the 3RB2123-4PD0 is a pure overload relay without integrated auxiliary contacts.","metaTitle":"Siemens 3RB2123-4PD0 SIRIUS Solid-State Overload Relay, Adju","metaDescription":"Siemens 3RB2123-4PD0 SIRIUS solid-state overload relay, adjustable trip class 5E/10E/20E/30E, contactor-mount, ATEX Ex II (2) GD. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Overload Relays"],"specifications":{"Depth":"75 mm","Solid":"2x (0.25 ... 1.5 mm²)","Width":"45 mm","Height":"73 mm","Upwards":"0 mm","at 24 V":"2 A","at 60 V":"0.55 A","Forwards":"0 mm","Per Pole":"0.02 W","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","Backwards":"0 mm","Downwards":"0 mm","Trip Class":"CLASS 5E, 10E, 20E and 30E adjustable","At The Side":"6 mm","During Storage":"-40 ... +80 °C","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","During Transport":"-40 ... +80 °C","Fastening Method":"Contactor mounting","Shock Resistance":"15g / 11 ms","Mounting Position":"any","Product Brand Name":"SIRIUS","Type Of Protection":"PTB 06 ATEX 3001 Ex II (2) GD","Product Designation":"solid-state overload relay","For Main Current Circuit":"screw-type terminals","Substance Prohibitance (Date)":"07/01/2006","at AWG cables for main contacts":"2x (14 ... 10)","For Auxiliary And Control Circuit":"spring-loaded terminals","Relative Humidity During Operation":"100 %","Surge Voltage Resistance Rated Value":"6 kV","at AWG cables for auxiliary contacts":"2x (24 ... 16)","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","number of CO contacts for auxiliary contacts":"0","number of NC contacts for auxiliary contacts":"1","number of NO contacts for auxiliary contacts":"1","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","Installation Altitude At Height Above Sea Level Maximum":"2 000 m","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/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":"0.05 W","Adjustable Current Response Value Current Of The Current-Dependent Overload Release":"1 ... 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=270552&mlfb=3RB2123-4PD0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RB2123-4PD0/alternatives.json"},"ai":{"faq":[{"question":"Will 3RB2123-4PD0 drop into a panel that was specified around 3RT1016-1AR11 without rewiring?","answer":"The 3RB2123-4PD0 mounts directly to a contactor (contactor mounting), so it fits the same mechanical footprint as the 3RT1016 series contactors. Wiring differs: main terminals are screw-type, auxiliary terminals are spring-loaded — verify terminal assignments against your existing panel drawing."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RB2123-4PD0","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/3RB2123-4PD0 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}}