What this MCCB does and the rating that matters
The Siemens 3VA2225-7KQ32-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection, carrying a continuous current Iu of 250 A across three poles. The interrupting capacity is what decides its fit in a distribution board: 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. That 330 kA at 240 V means it can safely clear a fault at the main service entrance where available fault current is highest — a typical 100 kA SCCR panelboard is well within its margin. The 4.5 kA at 690 V is the drop-off point; if your system runs 690 V with higher fault potential, this frame is not the right choice.
Thermal derating and trip unit
Rated current holds at 250 A from 40 °C through 50 °C ambient. At 55 °C it derates to 238 A, then 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. If the panel runs hot — say a non-ventilated enclosure next to a furnace line — the 70 °C figure of 200 A is the number to spec against, not the 250 A nameplate. The overcurrent release is an ETU860 electronic trip unit, which gives adjustable long-time, short-time, instantaneous, and ground-fault protection. Ground-fault monitoring uses summation current formation on the L-conductor, so it detects residual current without a separate core-balance transformer.
Panel fit and integration
Dimensions are 105 mm wide, 86 mm deep, 181 mm tall. That 105 mm width is three-pole wide — standard for a 250 A frame in a distribution board. The 86 mm depth means it clears most 200 mm deep enclosures with room for rear-connected busbars. Front face carries an IP40 protection class, so it is protected against tools and wires >1 mm but not against water ingress — keep it inside a dry panel. Communication function is built in, and a motor-drive extension is optional for remote tripping or re-closing.
Lifecycle and sourcing
Lifecycle stage is marked as current — meaning Siemens still lists it as an active catalog number with no announced end-of-life. That is the cleanest procurement scenario: no LTB window to chase, no successor to qualify. The part is sourced and quoted to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time. If you are freezing a BOM for a multi-year panel run, this is a stable line item.