The Schneider Electric TeSys LR3D1512 is a non-differential thermal overload relay for motor protection, with a thermal protection adjustment range of 5.5...8 A and a Class 20 tripping curve per IEC 60947-4-1. It is now classified as obsolete by the manufacturer.
The 5.5...8 A adjustment range sets the full-load motor current (Ir) the relay protects. Class 20 means it allows up to 20 seconds of locked-rotor current before tripping — standard for general-purpose induction motors starting under load, like conveyors or pumps. 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. Auxiliary contacts are 1 NO + 1 NC, rated 1.5 A at 240 V AC-15 for signalling circuits and 0.1 A at 250 V DC-13. That means the NC contact can drop out a holding circuit on trip, while the NO signals the alarm to a PLC input — standard for a motor starter interlock. The IP20 finger-safe enclosure suits panel-mount installation — not for washdown or outdoor use.
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, plus GB/T 14048.4 and 14048.5. Rated insulation voltage (Ui) is 600 V for CSA/UL and 690 V for IEC; rated operational voltage (Ue) is 690 V AC at 0...400 Hz. Impulse withstand (Uimp) is 6 kV.