Rated 125 A continuously at 40 °C, it holds that same 125 A rating up to 50 °C before the thermal derating curve starts to pull it down — at 70 °C it's still good for 114 A, so you've got some headroom in a hot enclosure. The interrupting capacity is where this breaker earns its keep: 76 kA at 240 V, 53 kA at 415 V, 32 kA at 440 V, and 12 kA at 500 V. That's a strong SCCR for a 125 A frame — it'll clear high-fault events without cascading upstream, which matters when you're coordinating a panel's selectivity.
The 3VM1112-3ED32-0AA0 measures 70 mm deep, 76.2 mm wide, and 130 mm tall — a compact footprint for a 125 A MCCB. It's designed for panel mounting, not DIN rail, so plan for screw-mounting on a backplate. Front protection is IP40, meaning it's splash-proof from the front but not sealed against dust ingress from the sides or rear — standard for enclosed distribution gear.
Thermal performance and power loss
Maximum power loss is 23 W at rated load — modest for a 125 A frame, so heat buildup in a dense panel is manageable. The derating curve is linear from 50 °C upward: 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, 114 A at 70 °C.