The C164MG160D is a thermal-magnetic trip unit from the Schneider Electric ComPacT NSX100...250 DC range, designed for DC generator protection. This means it's built to handle the continuous current and high DC voltage typical of generator output circuits — think backup gensets, solar farm DC combiners, or industrial DC bus distribution.
The long-time pickup (Ir) is adjustable from 0.7 to 1 x In (112 A to 160 A), giving you some field flexibility to match the generator's actual continuous rating. The instantaneous pickup (Ii) is fixed at 530 A — that's about 3.3 x In, which is a deliberate gap to ride through generator inrush without nuisance tripping. The thermal element has a fixed delay curve (tr fixed), so you're trusting the factory curve for overload coordination. This unit is rated for a DC network only, per the spec. That 750 V DC rating is the key number for fit — if your system is 500 V DC or 600 V DC nominal, this unit covers it with margin.
That's the spec you want for a generator protection device — it covers the thermal and magnetic performance curves, the dielectric withstand, and the short-circuit making and breaking capacity. Electrical shock protection is Class II, meaning double-insulated — no earth connection required on the trip unit itself.
What the IP40 and temperature range mean for installation
IP40 means this trip unit is for indoor panel use only — no washdown, no outdoor exposure. The 4-pole fixed mount means it clips into the ComPacT NSX DC breaker frame — no DIN rail, no separate enclosure. Swap it in the field if the breaker frame is already wired; just verify the trip unit is the same family (NSX100-250 DC).