What this frame carries
The C16BH4FM is a bare basic frame in the ComPacT NS1600b…3200 new generation range — no trip unit, no protection electronics. It's the structural and contact assembly for a 4-pole, fixed-mount air circuit breaker rated 1600 A continuous at 50 °C ambient. You add the control unit (Micrologic or separate trip module) to set the protection curves; this order code is just the power chassis. The 85 kA Icu at 415 V AC (125 kA at 240 V) puts it in the H breaking-capacity tier for the NS1600b frame.
Fixed backplate mount with a 70 mm connection pitch. The frame is 535 mm wide × 330 mm tall × 160 mm deep — plan the enclosure cutout and bus-bar drilling accordingly. Neutral is on the left by default. The front face carries Class II shock protection, so no separate ground bond is needed on the operator-facing side. IP40 enclosure protection and IK07 impact resistance suit it for indoor switchboard installation where tools or debris might strike the front cover, but not washdown environments.
Electrical durability and isolation
Mechanical endurance is 5000 cycles; electrical endurance varies by load: 1000 cycles at 690 V at full rated current, 2000 cycles at 440 V at full current, and up to 3000 cycles at half current.