The Schneider Electric C25F44V250 is a ComPacT NSX250F 4-pole moulded-case circuit breaker (MCCB) from the ComPacT NSX family, fitted with a MicroLogic 4.2 electronic trip unit.
Across the voltage range it delivers 85 kA Icu at 220/240 V AC, 36 kA at 380/415 V, 35 kA at 440 V, 30 kA at 500 V, 22 kA at 525 V, and 8 kA at 660/690 V, all per IEC 60947-2. Under UL 60947-4-1 it is rated 85 kA at 240 V, 35 kA at 480 V, and 15 kA at 600 V AC. For a buyer specifying into a 415 V panel, the 36 kA Icu gives headroom above typical 25 kA or 35 kA fault levels common in commercial distribution — you can use it downstream of a transformer without worrying about cascading failure on a bolted fault. The 85 kA at 240 V also makes it suitable for 240 V delta or split-phase services where fault currents can be high.
Trip unit and protection logic
The MicroLogic 4.2 is an electronic trip unit — not a thermal-magnetic — which means it holds its trip curve tighter across ambient temperature swings and offers adjustable long-time pickup and delay. Earth-leakage protection is integrated (no external toroid or relay needed), adjustable via the IΔn rotary switch. The trip unit is rated 250 A at 40 °C; above that temperature the breaker must be derated per the manufacturer's curve, but the 40 °C baseline covers most enclosed panel environments. The electronic design also enables local signalling: a green flashing LED for ready-to-operate, red LED at 105 % Ir for overload, and orange LED at 90 % Ir as a pre-alarm.
Physical fit and installation
The breaker measures 161 mm high by 140 mm wide by 86 mm deep, with a 35 mm connection pitch. Both line and load connections are front-facing, which simplifies busbar and cable routing in a switchboard. The IK07 impact rating confirms it can withstand a 2 J impact, which covers accidental tool drops during maintenance.