What this MCCB carries — and what it means for your panel
The Siemens 3VA2225-7HN32-0KA0 is a SENTRON 3VA2 molded case circuit breaker rated for 250 A continuous current (Iu) across a 3-pole configuration. That 250 A holds flat from 40 °C to 50 °C, then derates to 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, and 213 A at 70 °C — so if your panel ambient runs hot, the real ampacity is lower than the nameplate. Breaking capacity hits 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 6.3 kA at 690 V. That 330 kA at 240 V means it can interrupt very high fault currents typical on large transformer secondaries or busway feeds without upstream coordination headaches. The ETU350 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves — not a fixed thermal-magnetic. That matters when you need selective coordination downstream or want to dial in the trip for motor or transformer inrush without nuisance trips. This version ships with a shunt trip release (STL) for remote tripping via a control signal — useful for emergency-stop circuits or remote disconnect schemes. No undervoltage release, no auxiliary contacts, no communication module on this variant. The shunt trip is the only auxiliary release fitted.
Panel fit and integration
Dimensions: 105 mm wide, 181 mm tall, 86 mm deep. That 105 mm width is a standard 3-pole MCCB footprint for this current class. Maximum power dissipation is 48 W at rated current. That's not trivial — factor it into your enclosure thermal calculation, especially if the panel is densely packed or sealed. The operating temperature range is -25 °C to +70 °C; storage from -40 °C to +80 °C.
What this variant includes — and what it skips
Line protection version (not motor protection — no phase-failure detection, no undervoltage release). No trip indicator, no auxiliary contact block, no communication function, no ground-fault monitoring. The shunt trip (STL) is the only auxiliary release; its basic switch is order code 3VA2225-7HN32-0AA0, and the integrated auxiliary trip is 3VA9688-0BL33. Rated insulation voltage Ui is 800 V — sufficient for 690 V line-to-line systems with margin. The ETU350 is self-powered from the line current; no external control power needed for the trip unit itself (the shunt trip does need a separate control voltage).