{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LR3D3503","brand":"Schneider Electric","brandSlug":"schneider","productSlug":"LR3D3503","canonicalUrl":"https://aoctrl.com/schneider/LR3D3503","factsUrl":"https://aoctrl.com/api/mcp/products/LR3D3503","rawCanonicalId":null},"summary":{"shortDescription":"TeSys Deca thermal overload relay, LR3D3503, 37-50 A, Class 10A, 1 NO + 1 NC auxiliary contacts.","salesMarkdown":"The LR3D3503: The 37-50 A thermal protection adjustment range covers IEC frame-size motor loads drawing full-load current in that band. The phase-failure sensitivity trips at 130% of Ir on two phases with the third at zero, which catches a lost phase before the motor overheats. The impulse withstand is 6 kV, so it's fine for 480 V and 600 V panels in North America, and 400 V/690 V systems in IEC territories. The EverLink BTR screw connectors on the power circuit accept up to 35 mm² (AWG 2) flexible or solid wire, torqued to 5 N·m. Control circuit terminals are spring-cage, 1-2.5 mm². That's a mixed-termination setup — the power side needs a screwdriver, the control side doesn't. Make sure your wire prep matches: ferrules on the spring terminals, and the right torque driver for the power lugs. If you're in the middle of a line-down situation or a last-time-buy, the key thing is to confirm the thermal adjustment range (37-50 A) and the Class 10A curve match your motor nameplate. The physical footprint — 55 mm wide, 70 mm tall, 123 mm deep — and the mounting pattern under a TeSys D contactor are what determine whether a substitute fits the panel without rework.","metaTitle":"TeSys LR3D3503 Thermal Overload Relay, 37-50 A, Class 10A","metaDescription":"Obsolete TeSys Deca LR3D3503 thermal overload relay. 37-50 A adjustment range, Class 10A, 1 NO + 1 NC contacts. UL/CSA/IEC. Sourced to order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":[],"specifications":{"Depth":"4.8 in (123 mm)","Range":"TeSys","Width":"2.2 in (55 mm)","title":"LR3D3503","Height":"2.8 in (70 mm)","Category":"22347-CONTACTOR,D-LINE,OVERLOADS-NEW","Standards":"EN/IEC 60947-4-1 EN/IEC 60947-5-1 UL 60947-4-1 UL 60947-5-1 CSA C22.2 No 60947-4-1 CSA C22.2 No 60947-5-1 GB/T 14048.4 GB/T 14048.5","description":"TeSys Deca thermal overload relays - 37...50 A - class 10A","Control type":"Red push-button stop Blue push-button reset","Network type":"AC DC","Product name":"TeSys LRD TeSys Deca","lifecycle_stage":"current","Flame retardance":"V1 conforming to UL 94","Mounting support":"Plate, with specific accessories Rail, with specific accessories Under contactor","Device short name":"LR3D","Network Frequency":"0...400 Hz","Relay application":"Motor protection","Tightening torque":"Power circuit 44.3 lbf.in (5 N.m) EverLink BTR screw connectors","Climatic withstand":"IACS E10","Tripping threshold":"1.14 +/- 0.06 Ir IEC 60947-4-1","Dielectric strength":"1.89 kV 50 Hz IEC 60947-1","Permissible current":"0.95 A 380 V AC-15 signalling circuit 0.06 A 440 V DC-13 signalling circuit","Mechanical robustness":"Shocks15 Gn for 11 ms IEC 60068-2-7 Vibrations4 gn IEC 60068-2-6","Nbr. of units in pkg.":"1","Associated fuse rating":"4 A gG for signalling circuit 4 A BS for signalling circuit","Thermal overload class":"Class 10A IEC 60947-4-1","Connections - terminals":"Power circuit EverLink BTR screw connectors 1 0.002...0.05 in² (1...35 mm²) flexible without cable end Power circuit EverLink BTR screw connectors 1 0.002...0.05 in² (1...35 mm²) flexible with cable end Power circuit EverLink BTR screw connectors 1 0.002...0.05 in² (1...35 mm²) solid without cable end Control circuit spring terminals 1 0.002...0.004 in² (1...2.5 mm²) solid without cable end Control circuit spring terminals 1 0.002...0.004 in² (1...2.5 mm²) flexible without cable end","IP degree of protection":"IP20 conforming to IEC 60529","Temperature compensation":"-4...140 °F (-20...60 °C)","Phase failure sensitivity":"Tripping current 130 % of Ir on two phase, the last one at 0","Product or Component Type":"Non differential thermal overload relay","Auxiliary contact composition":"1 NO + 1 NC","[Ui] rated insulation voltage":"Power circuit 600 V CSA Power circuit 600 V UL Power circuit 690 V IEC 60947-4-1","[Ue] rated operational voltage":"690 V AC 0...400 Hz power circuit IEC 60947-4-1","Ambient Air Temperature for Storage":"-76...158 °F (-60...70 °C)","Thermal protection adjustment range":"37...50 A","Ambient air temperature for operation":"-4...140 °F (-20...60 °C) without derating IEC 60947-4-1","[Uimp] rated impulse withstand voltage":"6 kV","[Ith] conventional free air thermal current":"5 A signalling circuit"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/165b8ebcf3ab438974e6dcae3850d231.pdf","sourceUrl":"https://www.se.com/th/en/product/LR3D3503/tesys-deca-thermal-overload-relays-37-50-a-class-10a/","alternativesUrl":"https://aoctrl.com/api/mcp/products/LR3D3503/alternatives.json"},"ai":{"faq":[{"question":"What are the key ratings for the LR3D3503?","answer":"Thermal protection adjustment range is 37-50 A, Class 10A overload curve, with 1 NO + 1 NC auxiliary contacts. Rated operational voltage is 690 V AC on the power circuit. Phase-failure sensitivity trips at 130% of Ir on two phases with the third at zero."},{"question":"What standards does the LR3D3503 comply with?","answer":"It complies with EN/IEC 60947-4-1, EN/IEC 60947-5-1, UL 60947-4-1, UL 60947-5-1, CSA C22.2 No 60947-4-1, CSA C22.2 No 60947-5-1, and GB/T 14048.4/14048.5. Flame retardance is V1 per UL 94."},{"question":"What is the physical size of the LR3D3503?","answer":"It measures 55 mm wide, 70 mm tall, and 123 mm deep. It mounts under a TeSys D contactor or on a plate/rail with specific accessories."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/schneider/LR3D3503","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/schneider/LR3D3503 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:21:01.794Z","lastPublished":"2026-09-02T08:21:01.794Z","indexable":true}}