What this MCCB delivers — and what it asks of the panel
The Siemens SENTRON 3VA2225-5HN42-0BB0 is a 4-pole molded case circuit breaker rated for 250 A continuous, with an electronic ETU350 trip unit. Its interrupting capacity hits 187 kA at 240 V and still holds 121 kA at 415 V — figures that put it in the high-fault tier for industrial distribution, not a branch-rated device. The 4-pole construction means it switches all phases plus neutral, which matters for TN-S or IT systems where the neutral must be protected. At 140 mm wide, 181 mm tall, and 86 mm deep, it fits standard panel-mount cutouts for this frame size. The 50.5 W maximum power loss at rated load means the enclosure needs ventilation planning — that's not trivial heat in a sealed cabinet.
Selectivity and coordination — where the ratings matter
The ETU350 electronic trip unit gives adjustable long-time, short-time, and instantaneous protection bands, which is what you need for selective coordination downstream. The 250 A frame with 121 kA SCCR at 415 V means it can sit at the main or feeder position in a 400 V industrial panel and clear a bolted fault without upstream devices having to intervene — provided the let-through energy is coordinated with the next breaker down. The 4.5 kA rating at 690 V is a reminder that this frame is optimized for 240–500 V systems; at 690 V the interrupting capacity drops sharply, so verify the available fault current if that's your service voltage.
Thermal derating — the real-world continuous current
Rated 250 A at 40 °C, 45 °C, and 50 °C — no derating needed in that range. At 55 °C it drops to 241 A, at 60 °C to 232 A, at 65 °C to 222 A, and at 70 °C to 213 A. If the panel ambient runs hot (say, 55 °C inside a non-ventilated enclosure near a furnace line), the breaker still carries 241 A continuous, which is 96% of its nameplate. That's a tighter derating curve than some thermal-magnetic frames, so you don't lose as much headroom at elevated temperatures.
Auxiliaries and releases built in
The breaker ships with an undervoltage release (UVR) and two auxiliary switches (HP design). The UVR means the breaker trips if the control voltage drops — a standard safety feature for motor feeders or emergency-stop chains. The two auxiliary switches provide status feedback (open/closed) to a PLC or indication lamp without needing an external contact block. No ground-fault monitoring is included, so if GF protection is required, it must be added externally or via a different variant.
Integration into the panel
Mounts to a backplate via the standard MCCB footprint — not DIN-rail, so plan for screw-fixed mounting. The 140 mm width matches the common 4-pole frame envelope for this current class; verify the busbar or cable lug centers against your existing tap-off bars. The ETU350 is field-configurable via rotary dials on the front face, no software needed for basic settings.