The Schneider LUCB05ES is an advanced control unit in the TeSys Ultra range, designed specifically for motor control and protection in three-phase self-cooled motor applications. It provides earth fault protection, phase failure and imbalance detection, plus overload and short-circuit protection — all with a manual reset that keeps the circuit locked open until cleared by a qualified person. Sized at 2.4 in (60 mm) deep, 1.8 in (45 mm) wide, 2.6 in (66 mm) high, this unit mounts via plug-in front face connection — no tools needed to swap it on the TeSys Ultra base. That means a line-down replacement takes minutes, not hours. It carries utilization categories AC-43, AC-44, and AC-41 per IEC 60947-6-2, covering squirrel-cage motor starting and plugging/reversing duty. The tripping threshold is fixed at 14.2 x Ir ±20%, with sensitivity to phase failure and microbreaks down to 3 ms. If you're coordinating branch-curve protection, that 14.2 x Ir is your hard floor — it doesn't drift.
Lifecycle and Compliance — No Surprises
Compliance is fully listed: UL 60947-4-1 (with phase barrier), CSA C22.2 No 60947-4-1, IEC 60947-6-2, and EN 60947-6-2. The product carries IP20 on the front panel and wired terminals, IP40 on the front face outside the connection zone. For panel builders, that means no extra guarding in a typical Type 1 enclosure — just wire it and close it. Coordination with the LUB12, LUB32, or LUB38 control circuit is specified for operating times: 35 ms opening, 60 ms closing. Heat dissipation runs 2 W with the LUB12, 3 W with the LUB32 or LUB38. Panel thermal rise must account for these numbers — they're not negligible in a sealed enclosure.
Mounting and Environment Specifics
Plug-in mounting on the TeSys Ultra base means the control unit lifts off without disturbing power wiring. The front face interface is standard across the range, so a LUCB05ES drops in where any TeSys Ultra control unit sat before — verify the base model but expect mechanical interchange. Shock resistance: 10 gn with power poles open, 15 gn with poles closed (IEC 60068-2-27). Vibration: 2 gn at 5–300 Hz open, 4 gn closed (IEC 60068-2-6). This unit is built for machine-side panels on conveyors, presses, or pumps — not just static switchgear. Operating altitude is 2000 m; safe separation of circuits is 400 V SELV between control and main paths. Fire resistance is 960 °C for current-carrying parts, 650 °C standard (IEC 60695-2-12). No exceptions: this part won't propagate a panel fire under a motor fault.