{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LRD3355A66","brand":"Schneider Electric","brandSlug":"schneider","productSlug":"LRD3355A66","canonicalUrl":"https://aoctrl.com/schneider/LRD3355A66","factsUrl":"https://aoctrl.com/api/mcp/products/LRD3355A66","rawCanonicalId":null},"summary":{"shortDescription":"Schneider Electric TeSys LRD differential thermal overload relay, LRD3355A66, 30...40 A adjustment range, Class 10A, 1000 V.","salesMarkdown":"The Schneider Electric TeSys LRD3355A66 is a differential thermal overload relay for motor protection. It adjusts from 30 to 40 A and carries a Class 10A tripping curve per IEC 60947-4-1, meaning it protects standard induction motors against sustained overloads and phase-loss conditions. The relay trips at 1.14 ± 0.06 times the set current Ir per IEC 60947-4-1, and on phase failure it trips at 130 % of Ir on two phases with the third at zero. That differential action catches single-phasing before the motor cooks. Auxiliary contacts are 1 NO + 1 NC, rated 0.72 A at 500 V AC-15 for signalling circuits and 0.06 A at 440 V DC-13. The signalling circuit is fused at 4 A gG or 4 A BS. The LRD3355A66 is certified to EN/IEC 60947-4-1 and 60947-5-1, UL 60947-4-1 and 60947-5-1, CSA C22.2 No 60947-4-1 and 60947-5-1, and GB/T 14048.4 and 14048.5. Rated insulation voltage is 1000 V per IEC 60947-4-1 for the power circuit, 600 V per UL and CSA. Impulse withstand is 6 kV per IEC 60947-1. Power connections use M10 ring-lug terminals torqued to 11.3 N·m; control circuit uses screw clamp terminals accepting 1 to 2.5 mm² flexible or solid wire, torqued to 1.7 N·m. IP20 finger-safe protection for the enclosure.","metaTitle":"Schneider TeSys LRD3355A66 thermal overload relay, 30-40 A,","metaDescription":"Schneider Electric TeSys LRD3355A66 differential thermal overload relay, 30-40 A adjustment range, Class 10A. Obsolete status; sourced to order against RFQ. IEC/UL/CSA rated.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Overload Relays"],"specifications":{"Depth":"115 mm","Range":"TeSys","Width":"70 mm","Height":"81 mm","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","Control type":"Red push-button: stop Blue push-button: reset","Network type":"AC DC","Product name":"TeSys LRD","lifecycle_stage":"current","Connection pitch":"17.5 mm","Flame retardance":"V1 conforming to UL 94","Mounting support":"Plate, with specific accessories Rail, with specific accessories Under contactor","Device short name":"LRD","Network frequency":"0...400 Hz","Relay application":"Motor protection","Tightening torque":"Control circuit: 1.7 N.m - on screw clamp terminals Power circuit: 11.3 N.m - on lugs-ring terminals M10","Tripping threshold":"1.14 +/- 0.06 Ir conforming to IEC 60947-4-1","Dielectric strength":"2.2 kV at 50 Hz conforming to IEC 60947-1","Permissible current":"0.72 A at 500 V AC-15 for signalling circuit 0.06 A at 440 V DC-13 for signalling circuit","Mechanical robustness":"Vibrations: 6 Gn conforming to IEC 60068-2-6 Shocks: 15 Gn for 11 ms conforming to IEC 60068-2-7","Associated fuse rating":"4 A gG for signalling circuit 4 A BS for signalling circuit","Thermal overload class":"Class 10A conforming to IEC 60947-4-1","Connections - terminals":"Control circuit: screw clamp terminals 2 cable(s) 1...2.5 mm² flexible without cable end Control circuit: screw clamp terminals 2 cable(s) 1...2.5 mm² flexible with cable end Control circuit: screw clamp terminals 2 cable(s) 1...2.5 mm² solid without cable end Power circuit: lugs-ring terminals","IP degree of protection":"IP20 conforming to IEC 60529","Temperature compensation":"-20...60 °C","Phase failure sensitivity":"Tripping current 130 % of Ir on two phase, the last one at 0","Product or component type":"Differential thermal overload relay","Auxiliary contact composition":"1 NO + 1 NC","[Ui] rated insulation voltage":"Power circuit: 1000 V conforming to IEC 60947-4-1 Power circuit: 600 V conforming to CSA Power circuit: 600 V conforming to UL","[Ue] rated operational voltage":"1000 V AC 0...400 Hz for power circuit conforming to IEC 60947-4-1","Ambient air temperature for storage":"-60...70 °C","Thermal protection adjustment range":"30...40 A","Ambient air temperature for operation":"-20...60 °C without derating conforming to IEC 60947-4-1","[Uimp] rated impulse withstand voltage":"6 kV conforming to IEC 60947-1","[Ith] conventional free air thermal current":"5 A for signalling circuit"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.aoctrl.com/518dff9699e3265e5199fd536fda3d26.pdf","sourceUrl":"https://www.se.com/au/en/product/LRD3355A66/tesys-lrd-thermal-overload-relays-30-40-a-class-10a-1000v/","alternativesUrl":"https://aoctrl.com/api/mcp/products/LRD3355A66/alternatives.json"},"ai":{"faq":[{"question":"What replaces the LRD3355A66?","answer":"There is no official direct replacement listed. A current-production TeSys LRD or LR9 relay with a 30-40 A adjustment range and Class 10A may fit, but you must verify mounting, auxiliary contact configuration, and connection type against your existing panel layout."},{"question":"What are the key ratings of the LRD3355A66?","answer":"Thermal protection adjustment range 30-40 A, Class 10A, rated insulation voltage 1000 V (IEC) / 600 V (UL/CSA), impulse withstand 6 kV, auxiliary contacts 1 NO + 1 NC rated 0.72 A at 500 V AC-15."},{"question":"What compliance documentation is available for the LRD3355A66?","answer":"The relay is certified to IEC 60947-4-1 and 60947-5-1, UL 60947-4-1 and 60947-5-1, CSA C22.2 No 60947-4-1 and 60947-5-1, and GB/T 14048.4 and 14048.5. Flame retardance is V1 per UL 94."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/schneider/LRD3355A66","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/LRD3355A66 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}}