The LUCB05FUTQ is an advanced control unit from the TeSys U range, designed for basic protection and advanced functions including communication. It handles 3-phase motor loads — self-cooled — and delivers motor power ratings of 1.5 kW at 400...440 V AC 50/60 Hz, 2.2 kW at 500 V AC 50/60 Hz, and 3 kW at 690 V AC 50/60 Hz. That means it covers the common European 400 V line and steps up to 690 V for higher-voltage installations. The unit provides protection against overload, short-circuit, phase failure, phase imbalance, and earth faults. It resets manually, which is standard for a motor-protective device — you want a deliberate action after a trip, not an automatic restart that could catch maintenance off-guard. It mounts via a plug-in front face onto a TeSys U base, so the control unit swaps without disturbing the power wiring.
The control circuit voltage is 110...240 V AC and 110...220 V DC — a wide-range supply that covers most industrial control voltages without needing a separate transformer tap. Utilisation categories AC-41, AC-43, and AC-44 mean the unit is rated for switching resistive, motor, and other inductive loads under the IEC 60947-6-2 standard for motor starters and controllers. Rated insulation voltage is 690 V per IEC 60947-6-2 and 600 V per UL 60947-4-1 and CSA C22.2 No 60947-4-1, with a phase barrier required for the UL/CSA listing. That matters if the panel must carry a UL 508A label — the phase barrier is a mandatory add-on, not optional.
Where the TeSys U control unit is used
The LUCB05FUTQ lives inside a motor control centre or a standalone starter enclosure, plugged into a TeSys U power base that carries the contactor and overload sensing. It is the brains of the starter — it monitors current, decides when to trip, and communicates status. Above that, the air density drops and the thermal performance changes — standard for any electromechanical device, but worth noting if the panel is headed to a high-altitude site.