The Schneider Electric TeSys Ultra LUCL05B is a magnetic control unit — a compact, plug-in device that combines motor control and protection in a single 45 mm wide package. It is designed for 3-phase motor circuits, rated at 1.5 kW at 400...440 V AC, 2.2 kW at 500 V AC, and 3 kW at 690 V AC, all at 50/60 Hz. The 24 V AC control coil draws 140 mA inrush (220 mA with larger control modules) and settles to 70–90 mA sealed. The unit provides manual reset and short-circuit protection, with a tripping threshold of 14.2 x Ir ± 20%. It is specifically intended for protecting variable-speed drives or soft-start/soft-stop units, not just plain across-the-line starting. The utilisation categories — AC-41, AC-44, AC-43 — cover resistive, motor, and mixed loads, so it fits a range of downstream equipment.
The 14.2 x Ir tripping threshold means the unit allows a high inrush — typical for a motor starting — before it trips on a short-circuit. That is a deliberate design for motor circuits, not a general-purpose breaker characteristic. The 35 ms opening time (with any of the LUB12/32/38 control modules) means it clears a fault fast enough to limit let-through energy to downstream components. The SELV separation of 400 V between control/auxiliary and main circuits means the 24 V control loop is safely isolated from the power circuit — important for PLC or safety-relay interfaces. The TH protective treatment per IEC 60068 adds some humidity resistance for non-condensing environments.
The 45 x 66 x 60 mm footprint is compact enough for dense layouts. Heat dissipation is 2 W with the LUB12 control module, 3 W with LUB32 or LUB38 — negligible for most enclosures but worth noting if you are packing many units in a sealed cabinet.
The LUCL05B is certified to EN/IEC 60947-6-2, UL 60947-4-1, and CSA C22.2 No 60947-4-1 (with phase barrier). That covers the main global markets: IEC for Europe/Asia, UL for North America, CSA for Canada. The shock and vibration ratings — 10 gn open / 15 gn closed, and 2–4 gn at 5–300 Hz — confirm it holds up in machinery with moderate mechanical stress.