Its 250 A rated continuous current (Iu) holds flat from 40 °C through 50 °C, then derates to 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C — so in a warm enclosure without forced cooling, the effective ampacity drops to 225 A at 60 °C ambient. The interrupting ratings climb to 330 kA at 240 V and 242 kA at 415 V and 440 V, then drop to 187 kA at 500 V and 6.3 kA at 690 V.
Trip unit, auxiliaries, and panel integration
The ETU850 electronic trip unit provides adjustable long-time, short-time, instantaneous, and ground-fault protection curves — it's the programmable tier in the 3VA family, not the fixed thermal-magnetic. Communication function is built in, meaning it can report status and trip events over the SENTRON bus system. The 86 mm depth, 105 mm width, and 181 mm height fit the standard 3VA3/3VA2 panel cutout; the IP40 front protection is typical for indoor switchgear — no washdown rating, so keep it behind a gland plate or enclosure door in wet environments.