The C106TM025C is a TM-D thermal-magnetic trip unit for the Schneider Electric ComPacT NSX100 molded-case circuit breaker platform. Rated 25 A at 50 °C, it provides LI protection — L (thermal overload) and I (magnetic short-circuit) — across 4 poles configured as 3D (three protected poles, neutral unprotected). It is built to EN/IEC 60947-2, so the interrupting ratings and coordination data follow that standard, not the residential MCB curve.
If the panel runs hotter than 50 °C, the thermal element will trip earlier — the TM-D does not have an electronic temperature-compensation curve, so derate per the standard IEC 60947-2 thermal correction table for the actual enclosure temperature. That is a relatively high magnetic threshold, designed for distribution feeders where you want to ride through motor inrush without tripping. For a 25 A feeder feeding a 7.5 kW motor starting DOL, the inrush will pass cleanly; for a long cable run with high capacitive charging current, the 300 A threshold still leaves headroom. The long-time pickup (Ir) is adjustable from 0.7 to 1.0 x In, so you can set the thermal trip threshold between 17.5 A and 25 A. That lets you fine-tune the overload protection to match the actual load current without changing the trip unit. The fixed long-time delay gives a 120–400 s band at 1.5 x Ir and a 15 s floor at 6 x Ir — adequate for most distribution and light motor loads, but not selectable for tight coordination with downstream breakers. Rated operational voltage goes to 690 V AC and 750 V DC. The 690 V AC rating covers 400 V and 480 V systems with margin; the 750 V DC rating matters for photovoltaic or battery-bank applications where the DC bus sits above 600 V. The 4-pole 3D configuration leaves the neutral unprotected (no thermal element on the neutral pole), which is standard for 3-phase + N distribution where the neutral is not expected to carry sustained overload current.
This is the trip unit only — it snaps into the ComPacT NSX100 breaker frame. If the panel sees condensation or conductive dust, the IP40 front cover should be kept closed during operation.