The C103MG016 is a TM-G thermal-magnetic trip unit for the ComPacT NSX100...250 molded-case circuit breaker platform, rated 16 A at 40 °C with three protected poles (3D). It is designed specifically for generator protection — the TM-G curve provides the coordination needed between the generator's output and downstream distribution, avoiding nuisance tripping on inrush or transient loads that a standard distribution trip unit might pick up. The trip unit offers LI protection: a thermal (L) element for overload protection with an adjustable long-time pickup (Ir) from 0.7 to 1.0 x In, and a fixed magnetic (I) element for short-circuit protection set at 63 A. The long-time delay (tr) is fixed at 120 to 400 seconds at 1.5 x In, which suits generator thermal time constants. Rated operational voltage is 690 V AC at 50/60 Hz or 750 V DC, and the unit carries pollution degree 3 per IEC 60947-1, meaning it is suitable for industrial environments where conductive pollution or condensation may occur. The IP40 front face (IEC 60529) keeps tools and fingers out but is not sealed against moisture — mount inside a panel if washdown is present.
This means it has been tested for rated short-circuit breaking capacity, coordination, and insulation coordination. It also carries Class II electrical shock protection, so no separate protective earth connection is required on the trip unit itself.
Deployment context
This trip unit snaps into a ComPacT NSX100...250 fixed-mount breaker. For generator applications, coordinate the long-time delay with the generator's thermal damage curve — the fixed 120–400 s window at 1.5 x In is typical for medium-sized gensets but should be verified against the generator manufacturer's published curve during commissioning. No earth-leakage protection is integrated; if ground-fault detection is needed, add an external Vigi module or a separate earth-leakage relay. The 3D protected poles cover all three phases; the neutral is unprotected unless a 4-pole breaker is used.