The Schneider Electric LUCA32BTQ is a standard control unit in the TeSys U motor-starter family, designed to sit on a TeSys U power base and handle basic motor protection: overload, short-circuit, phase failure, phase imbalance, and earth fault. It is a plug-in front-face module — no need to rewire the base when swapping control logic or protection class. Rated for motor loads up to 15 kW at 400…440 V AC and 18.5 kW at 690 V AC, it covers the common European 400 V three-phase line and 690 V industrial networks. The utilisation categories AC-43, AC-44, and AC-41 tell you it is rated for both normal and frequent starting of squirrel-cage motors, including plugging and reversing duty — not just resistive loads. The thermal overload class is Class 10, meaning it trips within 10 seconds at 7.2× Ir, temperature-compensated from –25 °C to 70 °C. That matches the IEC 60947-6-2 and UL 60947-4-1 standards cited on the nameplate, so it is accepted in both IEC and North American panels with the right phase barrier.
Control voltage is 24 V AC, with a pickup range of 20…26.5 V and dropout at 14.5 V. The inrush while closing pulls 220 mA; sealed steady-state draw is 90 mA. That is a modest load on a 24 V AC control transformer — factor it into the transformer sizing if you are running several starters from one supply. The tripping threshold for magnetic short-circuit protection is 14.2 × Ir ±20 %, which means the instantaneous trip point is fixed relative to the thermal rating plug (Ir) you install on the power base. No separate adjustment — you set the overload protection via the rating plug, and the magnetic trip follows proportionally. Operating times are 35 ms opening and 70 ms closing when paired with the LUB32 or LUB38 control-circuit interface. That is fast enough for most motor-starting sequences but not a high-speed disconnect — plan for the clearing time in your coordination study.
Because it is a plug-in module, you can stock one LUCA32BTQ as a common spare for multiple TeSys U power bases of the same frame size — the control unit determines the protection logic and voltage, while the power base carries the main current path. That simplifies MRO inventory if your plant standardises on TeSys U.