The Schneider Electric TeSys LRD3322A66 is a differential thermal overload relay for motor protection, with a thermal protection adjustment range of 17...25 A and a tripping class of Class 10A per IEC 60947-4-1. It is designed for direct mounting under a contactor and provides phase failure sensitivity — tripping at 130% of Ir on two phases with the third at zero.
The 17...25 A adjustment range sets the motor full-load current window; set the dial to the motor nameplate FLA. Class 10A means the relay trips within 10 seconds at 7.2x the current setting — fast enough for most standard induction motor starts but not for high-inertia loads that need a Class 20 or 30. The 1.14 ± 0.06 Ir tripping threshold per IEC 60947-4-1 means the relay will trip between 108% and 120% of the set current under steady overload. Rated insulation voltage (Ui) is 1000 V for the power circuit per IEC 60947-4-1, and 600 V per UL/CSA — confirm your system voltage against the applicable standard for your jurisdiction. The auxiliary contact composition is 1 NO + 1 NC, rated 0.72 A at 500 V AC-15 for signalling circuits.
Certified to 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 14048.4/5. Flame retardance rating V1 per UL 94. IP20 finger-safe protection per IEC 60529.
Integration Notes
Mounts directly under a TeSys contactor or on a plate/rail with specific accessories. Dimensions: 81 mm height, 70 mm width, 115 mm depth. Control circuit terminals are screw clamp, accepting 1...2.5 mm² flexible or solid wire. Power circuit uses lugs-ring terminals with M10 hardware, torqued to 11.3 N·m.