What the ratings mean for fit
The Siemens SENTRON 3VA2225-7HM32-0DH0 is a 3-pole molded case circuit breaker (MCCB) rated for 250 A continuous current at 40 °C through 50 °C ambient — no derating needed in a typical 40 °C panel. Above 50 °C it steps down: 241 A at 55 °C, 232 A at 60 °C, 222 A at 65 °C, 213 A at 70 °C. That thermal curve governs the actual load you can hang on it in a warm enclosure; the 250 A nameplate is only valid up to 50 °C ambient. Interrupting capacity is the other gate. This breaker clears 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 4.5 kA at 690 V. The 690 V figure is the one that matters for 690 V drives or transformer secondaries — it's still a usable 4.5 kA, but if your available fault current at that voltage exceeds it, you need a higher-rated frame. Dimensions are 105 mm wide, 181 mm high, 86 mm deep — a standard SENTRON 3VA frame that mounts on DIN rail or a mounting plate. The 86 mm depth is the dimension that matters for shallow enclosures or gland-plate clearance behind the panel door.
Built-in accessories and wiring
This variant ships with an undervoltage release (UVR) and a 2-auxiliary-switch + 1-trip-alarm-switch HQ block. The UVR means the breaker drops out when control voltage is lost — common for emergency-stop circuits or safety isolation where a loss of control power should open the main. The auxiliary switches provide status feedback to a PLC or indicator lamp; the trip alarm switch signals a fault trip separately from a manual open. Rated insulation voltage is 800 V, so the breaker is suitable for 690 V systems with margin. Maximum power loss is 50.5 W — account for that heat in the enclosure thermal calculation, especially if multiple breakers are ganged.