The C25W45E160 is a 4-pole ComPacT NSX moulded-case circuit breaker from Schneider Electric, fitted with a MicroLogic 5.2 E electronic trip unit rated at 160 A at 40 °C. The trip unit provides L (long-time overload), S (short-time short-circuit), and I (instantaneous short-circuit) protection — the S function enables selective coordination downstream, so a fault on a branch feeder clears before this main trips, keeping the rest of the bus live. Breaking capacity is 100 kA Icu at 500 V, 525 V, and 660/690 V AC 50/60 Hz per IEC 60947-2, which means it can safely interrupt a fault current up to 100 kA at those voltages without welding contacts or rupturing the case. That puts it in the HB2 performance class — high-interrupting capacity for industrial distribution where fault currents are stiff.
Dimensions are 161 mm high by 140 mm wide by 86 mm deep, with a 35 mm connection pitch that matches standard Schneider busbar systems.
Durability and environmental limits
Mechanical endurance is 20,000 cycles; electrical durability varies with voltage and load — 20,000 cycles at 440 V at half rated current, 10,000 cycles at full rated current at 440 V, and 5,000 cycles at 690 V at half rated current. That's typical for a power breaker — it's not a contactor meant for frequent switching, but it handles routine isolation and infrequent fault clearing without issue. Operating altitude is 0–2000 m without derating, 2000–5000 m with derating. Relative humidity range is 0–95 % non-condensing. IK07 impact rating means it survives a 2 J blow — enough for accidental tool contact in a panel, not for a hammer strike.