The interrupting ratings climb to 187 kA at 240 V and hold at 121 kA through 440 V, then drop to 79 kA at 500 V and 5.1 kA at 690 V — so the SCCR you need for the fault-current study has to be checked at the actual system voltage, not the headline number. The thermal derating curve is published: full 250 A up to 50 °C, then 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. The unit draws 48 W maximum power loss, which adds to the enclosure heat budget. The basic switch reference is 3VA2225-5JP32-0AA0; the integrated shunt trip is 3VA9688-0BL30.
The ETU550 is an electronic overcurrent release with communication capability — it supports the SENTRON powerconfig software for parameterization and event logging. The shunt trip (STL) is included for remote tripping, wired to a separate control voltage. The unit has a voltage trigger function and a mechanical endurance of 20,000 operations. The unit does not include a trip indicator or phase-failure detection.