What this MCCB carries
The Siemens SENTRON 3VA2225-7HL32-0BL0 is a 3-pole molded case circuit breaker rated for 250 A continuous current at 40 °C, with an ETU320 electronic trip unit configured for line protection. It includes an undervoltage release (UVR) as the auxiliary release, plus a set of auxiliary contacts: 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ variant). The interrupting rating hits 330 kA at 240 V, stepping down to 242 kA at 415 V and 440 V, 187 kA at 500 V, and 6.3 kA at 690 V.
Thermal derating and real-world current
The 250 A rating holds flat from 40 °C through 50 °C. Above that, it derates: 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. If your panel ambient runs hot, that 213 A at 70 °C is your actual limit — not the nameplate 250 A. The maximum power loss is 50.5 W, which matters for enclosure thermal budgeting.
Panel fit and mounting
Dimensions: 105 mm wide, 181 mm tall, 86 mm deep. Standard SENTRON 3VA footprint — mounts on a mounting plate or DIN rail adapter. The UVR coil and auxiliary contact block are factory-integrated; no field wiring of separate accessories needed for the alarm and switch functions listed.
What the ETU320 trip unit does
The ETU320 is an electronic overcurrent release for line protection. It provides adjustable long-time, short-time, and instantaneous pickup settings, plus ground-fault alarm capability (though this variant ships without ground-fault monitoring). The rated insulation voltage is 800 V, and the mechanical endurance is 20,000 operations. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.