The Schneider Electric C10B4TM050 is a ComPacT NSX100B frame circuit breaker, 4-pole, rated 50 A at 40 °C with a TM-D thermal-magnetic trip unit (L for overload, I for short-circuit). It is designed for distribution applications and carries a breaking capacity of 25 kA Icu at 380/415 V AC 50/60 Hz per EN/IEC 60947-2 — that is the fault current it can safely interrupt without welding contacts or rupturing the case in a 415 V panel. The 4P configuration with neutral on the left and 1 x Ir neutral protection setting suits it for three-phase plus neutral distribution boards where phase and neutral are both switched and protected. The 140 mm width and 161 mm height fit standard ComPacT NSX cutouts; the 86 mm depth leaves clearance for rear-mounted accessories like auxiliary contacts or shunt trips.
The TM-D trip unit provides fixed thermal-magnetic protection: the thermal element (L) for overload and the magnetic element (I) for short-circuit, with no electronic adjustability. That makes it a straight replacement for a panel where the trip curve is already known and no coordination tuning is needed. The IP40 front face and IK07 impact resistance are typical for enclosed panel-mount breakers; the housing withstands tool impact but is not rated for washdown environments. Electrical durability is specified per switching cycle: 50,000 cycles at 440 V at In/2, 30,000 at 440 V at In, and 10,000 at 690 V at In. Mechanical durability is 50,000 cycles. For a distribution breaker switched infrequently (a few times a year for maintenance isolation), these numbers are well beyond the service life of the panel. For a breaker used as a daily disconnect on a machine, the 30,000-cycle figure at rated current still represents years of operation.