What this MCCB is and where it fits
The Siemens SENTRON 3VA1225-6EF32-0AC0 is a 3-pole molded case circuit breaker (MCCB) built for line protection — the main disconnect or feeder breaker in a distribution panel. It carries a TM240 thermal-magnetic overcurrent release, rated 250 A continuous at 40 °C, and holds that rating flat through 50 °C before a gentle derate curve kicks in: 243 A at 55 °C, 237 A at 60 °C, 230 A at 65 °C, 223 A at 70 °C. That interrupting capacity is the headline number here — 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, 30 kA at 500 V, and 17 kA at 690 V. Those are short-circuit current ratings (SCCR) you can coordinate downstream gear against, which matters when you're feeding a panel full of motor starters or smaller branch breakers.
What the ratings mean for your panel
Insulation voltage is rated 800 V. The 70 mm depth, 105 mm width, and 158 mm height are standard 3VA frame dimensions — it fits the same footprint as other SENTRON 3VA breakers in the 250 A range. Power loss is 57 W maximum at rated load — that's heat that has to leave the enclosure. In a sealed panel with multiple breakers ganged together, that number drives the ventilation or derating calculation. The operating range is -25 °C to 70 °C, with storage from -40 °C to 80 °C, so it handles a hot pump house or a freezing warehouse without drama.
Integration notes
This is a line-protection breaker, not a motor-protective device — it's designed for feeder duty, not overload protection of a specific motor. The TM240 release is thermal-magnetic: the thermal element handles overloads, the magnetic element handles short circuits. No ground-fault monitoring, no undervoltage release, no communication function — it's a straight-up power breaker. The auxiliary switch configuration is 2 auxiliary switches HQ (high-qualified), which means you get two form-C contacts for status feedback to a PLC or annunciator. The basic switch part number is 3VA12256EF320AA0 — that's the internal switching mechanism, not something you'd order separately unless you're rebuilding a damaged unit.