400 A MCCB with a wide interrupting-capacity envelope
Interrupting capacity — what the voltage columns tell you
This breaker delivers 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V. The steep drop above 500 V means the 690 V rating governs any high-voltage bus application; for most 400 V-class industrial feeds the 121 kA figure provides substantial fault-current headroom.
Above that, the breaker derates linearly: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C.
The 138 mm width matches the common 3-pole molded-case breaker slot; verify the bus-bar drilling pattern against the existing panel cutout.