What this MCCB is and what it does
The SENTRON 3VA2225-7HN32-0AC0 is a 3-pole molded case circuit breaker (MCCB) rated for 250 A continuous current, designed for line protection in distribution panels. Its interrupting capacity ranges from 330 kA at 240 V down to 4.5 kA at 690 V — the 330 kA figure at 240 V is the headline number for high-fault service-entrance applications where available short-circuit current is substantial. The 242 kA at 415 V and 440 V covers the common European low-voltage distribution voltages, while the 187 kA at 500 V suits industrial 480 VAC systems. At 690 V the rating drops to 4.5 kA, which still handles most motor-circuit faults at that voltage level.
Thermal derating and real-world current handling
This breaker carries its full 250 A rating from 40 °C through 50 °C ambient. Above that it derates linearly: 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C. The maximum operating ambient is 70 °C, with storage range from -40 °C to 80 °C. For a panel running warm — say 55 °C inside the enclosure — the usable current is 241 A, not the nameplate 250 A. That 9 A difference matters when sizing for a continuous load near the limit.
Physical fit and panel integration
Dimensions are 86 mm deep, 105 mm wide, and 181 mm tall. The 105 mm width is the standard 3-pole MCCB footprint for this frame size — it occupies three 35 mm DIN-rail modules plus a small overhang. No undervoltage release, no voltage trigger, no ground-fault monitoring, and no communication function on this variant. The two HQ auxiliary switches are the only integrated accessories.