It's a 3-pole unit rated 40 A continuous at 40 °C, and it holds that rating all the way to 50 °C before it starts to derate: 39 A at 55 °C, 38 A at 65 °C, 37 A at 70 °C. That thermal stability means you don't lose headroom in a warm enclosure. The interrupting rating is where this breaker earns its keep: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and still 11.9 kA at 690 V. That's a high-fault-current design — sized for a main breaker position where the utility transformer can dump serious energy into a bolted fault.
Auxiliary and shunt trip configuration
That's the '4EF32' part of the order code — the shunt trip lets a remote signal (emergency stop, fire alarm, PLC interlock) open the breaker without anyone pulling the handle. The trip alarm switch closes when the breaker trips on fault, so a panel PLC or annunciator sees the event. No undervoltage release on this unit, and no ground-fault monitoring module. If you need UVR or GF protection, you'd step to a different suffix in the 3VA family. The auxiliary switches are wired via the standard SENTRON terminal block — same footprint as the base breaker.