Basic frame for a distribution breaker
The C063N4FM is a basic frame in the ComPacT NS630b...1600 new generation range — a manually operated, fixed-mount 4-pole chassis rated 630 A at 50 °C. It ships without a protection control unit or trip block; the buyer selects and installs the electronic or micrologic trip separately to define overcurrent, ground-fault, and zone-selective interlocking behavior. This is standard practice for high-current frames where the trip curve must match the load profile (transformer, feeder, generator). The frame itself carries the full interrupting duty: 50 kA Icu at 415 V AC, 85 kA at 240 V, tapering to 30 kA at 690 V — all per IEC 60947-2, category B (unlimited selectivity). Mounting is fixed to a backplate via 70 mm connection pitch. Neutral is on the left. The front face offers Class II shock protection; the enclosure is IP40 with IK07 impact resistance.
Breaking capacity and service continuity
For most distribution boards fed by a 1 MVA or smaller transformer, 50 kA at 415 V provides adequate fault clearance. The Ics matches Icu at 415 V — 50 kA — so the breaker can be reclosed immediately after clearing a fault at that voltage without derating, per IEC 60947-2. At 690 V, Ics equals Icu at 30 kA.
Fixed backplate mount, 280 mm wide × 224 mm tall × 147 mm deep. The 70 mm pole-to-pole pitch is standard for busbar connection in switchboards. Power dissipation is 10 W at rated current — negligible for enclosure thermal rise but worth noting if the cubicle is densely packed.