The C063B3FM is a basic frame from the Schneider Electric ComPacT NS630b...1600 new generation range — a 3-pole, fixed-mount, manually operated air circuit breaker frame rated 630 A at 50 °C. It ships without a protection unit or trip block, so you select and install the control unit separately to match the protection curve your distribution board needs.
The Icu holds at 200 kA from 220/240 V through 440 V AC, then drops to 100 kA at 500/525 V and 75 kA at 660/690 V. The Ics (service breaking capacity) mirrors those numbers at each voltage level — meaning after clearing a fault at those currents the breaker can be reclosed and carry load again, not just survive one-shot. That is a real differentiator from older frames where Ics was a fraction of Icu.
If you are freezing a BOM for a new switchboard, this is the frame to specify — the older NS630b (non-LB) is the predecessor, and the new generation shares the same mounting footprint and connection pitch (70 mm) but carries higher breaking capacities.
Fixed-mount on a backplate, 210 mm wide × 224 mm high × 147 mm deep. The 70 mm connection pitch matches the standard busbar drilling pattern for this class. IP40 front face and IK07 impact rating — fine for a clean indoor switchroom; not rated for washdown.
Electrical durability and isolation
Mechanical endurance is 10,000 cycles. Electrical durability varies with voltage and current: 2,000 cycles at 690 V at full In, 4,000 cycles at 440 V at In/2. Rated impulse withstand voltage is 8 kV, overvoltage category III, insulation voltage 800 V.