{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"3RB2026-2NB0","brand":"Siemens","brandSlug":"siemens","productSlug":"3RB2026-2NB0","canonicalUrl":"https://aoctrl.com/siemens/3RB2026-2NB0","factsUrl":"https://aoctrl.com/api/mcp/products/3RB2026-2NB0","rawCanonicalId":null},"summary":{"shortDescription":"Siemens SIRIUS solid-state overload relay, 3RB2026-2NB0, CLASS 20E trip, contactor mounting, IP20, ATEX Ex II (2) GD, 45 x 73 x 75 mm.","salesMarkdown":"The Siemens SIRIUS 3RB2026-2NB0 is a solid-state overload relay for motor protection. It's the electronic version of a traditional bimetal overload — it monitors motor current and trips on overload, but without the thermal lag or drift you get from a heater element. The trip class is CLASS 20E, which means it's calibrated to trip in about 20 seconds at 7.2x the full-load current setting. That's the standard for standard-duty motor starting — it lets a motor accelerate under load without nuisance tripping, but still clears a stalled rotor fast enough to protect the winding insulation. This relay mounts directly onto a contactor — the evidence lists \"contactor mounting\" as the mounting type. That means it snaps onto the bottom of a SIRIUS contactor, forming a compact motor starter package. The footprint is 45 mm wide, 73 mm tall, and 75 mm deep, so it's a slim unit that doesn't eat up much DIN-rail space when you're building a multi-motor panel. Side clearance of 6 mm is needed for heat dissipation — the solid-state output stage does generate some heat, so don't bury it against another heat source. They accept solid conductors from 0.5 mm² up to 4 mm², and you can double up with 2x 0.5 to 2.5 mm² on each terminal. For AWG, that's 2x 14 to 10 AWG for the main contacts. That's enough for the motor leads on most small to medium induction motors. The auxiliary contacts — and there are zero of them built in, so any signaling needs a separate auxiliary contact block — are rated at various voltages: 2 A at 24 V, 4 A at 120 V, 3 A at 230 V, and so on. That's for the contact block you add, not the relay itself. ## Environmental and protection ratings It carries ATEX certification PTB 06 ATEX 3001 Ex II (2) GD, which means it's approved for use in potentially explosive atmospheres (Zone 2 gas, Zone 22 dust) when installed in an appropriate enclosure. It's rated for 100% relative humidity during operation, so condensation inside a non-condensing panel is fine. ## Electrical robustness and EMC It passes EMC burst immunity at severity level 3: 2 kV on power ports, 1 kV on signal ports per IEC 61000-4-4. Shock resistance is 15g for 11 ms, which covers most vibration from contactors and starters in the same panel. Power dissipation is low — 0.05 W total in hot operating state, or 0.02 W per pole — so it won't contribute much heat to the panel.","metaTitle":"Siemens SIRIUS 3RB2026-2NB0 solid-state overload relay, CLAS","metaDescription":"Siemens SIRIUS 3RB2026-2NB0 solid-state overload relay, CLASS 20E trip, ATEX Ex II (2) GD, IP20, contactor mount, 45mm wide. Sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":null,"categoryPath":["Overload Relays"],"specifications":{"Depth":"75 mm","Solid":"0.5 ... 4 mm², 2x (0.5 ... 2.5 mm²)","Width":"45 mm","Height":"73 mm","Maximum":"2 000 m","Upwards":"0 mm","at 24 V":"2 A","at 60 V":"0.55 A","Forwards":"0 mm","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 20E","At The Side":"6 mm","On The Front":"IP20","Mounting type":"Contactor mounting","During Storage":"-40 ... +80 °C","lifecycle_stage":"current","During Operation":"-25 ... +60 °C","During Transport":"-40 ... +80 °C","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 Auxiliary Contacts":"0","For Main Current Circuit":"screw-type terminals","at AC-3 rated value maximum":"690 V","at AC in hot operating state":"0.05 W","Relative humidity during operation":"100 %","due to burst acc. to IEC 61000-4-4":"2 kV (power ports), 1 kV (signal ports) corresponds to degree of severity 3","at AWG conductors for main contacts":"2x (14 ... 10)","Surge voltage resistance rated value":"6 kV","Reference code acc. to DIN EN 81346-2":"F","at AC in hot operating state per pole":"0.02 W","With Degree Of Pollution 3 Rated Value":"690 V","Finely Stranded With Core End Processing":"0.5 ... 2.5 mm², 2x (0.5 ... 1.5 mm²)","Number of poles for main current circuit":"3","at AWG conductors for auxiliary contacts":"2x (20 ... 14)","For Auxiliary And Control Current Circuit":"screw-type terminals","Number of NC contacts for auxiliary contacts":"1","Number of NO contacts for auxiliary contacts":"1","Electrostatic discharge acc. to IEC 61000-4-2":"6 kV contact discharge / 8 kV air discharge","Size of contactor can be combined company-specific":"S0","due to conductor-earth surge acc. to IEC 61000-4-5":"2 kV (line to earth) corresponds to degree of severity 3","Removable Terminal For Auxiliary And Control Circuit":"Yes","For Short-Circuit Protection Of The Auxiliary Switch Required":"fuse gL/gG: 6 A","Adjustable pick-up value current of the current-dependent overload release":"0.32 ... 1.25 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$209.83","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://support.industry.siemens.com/webbackend/api/ProductSupport/TechnicalData?language=en&region=cn&productId=323430&mlfb=3RB2026-2NB0","alternativesUrl":"https://aoctrl.com/api/mcp/products/3RB2026-2NB0/alternatives.json"},"ai":{"faq":[{"question":"What are the key ratings for the 3RB2026-2NB0?","answer":"It's a CLASS 20E solid-state overload relay, contactor-mounted, 45 mm wide, IP20 front protection, ATEX Ex II (2) GD certified, with screw terminals accepting 0.5 to 4 mm² conductors. Operating temperature is -25 to +60 °C, and it withstands 6 kV surge at pollution degree 3."},{"question":"What does CLASS 20E mean for motor protection?","answer":"CLASS 20E means the relay is calibrated to trip in approximately 20 seconds at 7.2 times the full-load current setting. This is the standard trip class for general-purpose motor starting, allowing the motor to accelerate under load without nuisance tripping while still protecting against a stalled rotor."},{"question":"What certifications does the 3RB2026-2NB0 carry?","answer":"It carries ATEX certification PTB 06 ATEX 3001 Ex II (2) GD for use in potentially explosive atmospheres (Zone 2 gas, Zone 22 dust) when installed in a suitable enclosure. It also meets EMC immunity per IEC 61000-4-4 severity level 3."},{"question":"What is the physical size of the 3RB2026-2NB0?","answer":"It measures 45 mm wide, 73 mm tall, and 75 mm deep. It requires 6 mm side clearance for heat dissipation."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/siemens/3RB2026-2NB0","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/3RB2026-2NB0 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}}