It's a 3-pole unit built for line protection, carrying interrupting ratings that climb to 440 kA at 240 V — that's serious fault-clearing headroom for high-capacity distribution panels.
Interrupting ratings and selectivity
This breaker's interrupting capacity drops as voltage rises: 440 kA at 240 V, 330 kA at 415 V and 440 V, 220 kA at 500 V, and 53 kA at 690 V. For a 40 A frame, those numbers give you wide selectivity margins downstream — you can coordinate with smaller branch breakers without worrying about nuisance tripping on a fault upstream. The ETU550 electronic trip unit is adjustable, with short-time delay (tsd) settings from 0.5 s to 0.5 s, and thermal memory for repeated faults.
Communication function is built in, which simplifies integration with a BMS or power monitoring system without an external module.