What this MCCB carries — and what that means for your panel
The Siemens 3VA2325-7KQ42-0AA0 is a SENTRON 3VA2 molded case circuit breaker, 4-pole, rated 250 A continuous current with a flat thermal derating curve from 40 °C through 70 °C — meaning you don't lose ampacity as the panel warms up, a real advantage in a crowded enclosure. Breaking capacity hits 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 7.5 kA at 690 V. That 330 kA at 240 V is the headline number — it clears a massive fault without cascading upstream, sized for the main incoming breaker position in a high-fault industrial distribution board. The ETU860 electronic trip unit gives you adjustable long-time, short-time, instantaneous, and ground-fault protection, with N-conductor protection adjustable from OFF through 20% to 160%. Ground-fault monitoring uses summation current formation on L+N, so it catches leakage without an external CT. Communication function is built in — this breaker talks to the control system, so you get remote trip indication and load monitoring without an add-on module. Mechanical endurance is rated at 20 000 operations, and maximum power loss is 37.5 W — the heat it dumps into the panel is manageable, but factor it into your thermal budget if the enclosure is sealed.
Mounting and integration
Footprint is 248 mm high, 184 mm wide, 110 mm deep — a 4-pole frame that bolts into a standard MCCB mounting plate. IP40 on the front means it's protected against solid objects larger than 1 mm, but not sealed against moisture; keep it inside the panel, not on the washdown side of the gland plate. Rated insulation voltage is 800 V, so it's comfortable on 480 V and 600 V class systems with margin. Storage range is -40 °C to 80 °C; operating range -40 °C to 70 °C — the storage limit is the handling limit, not the running limit.
Lifecycle and sourcing reality
If you're replacing a 5SQ2670-2YA63 or similar legacy frame, the 3VA2325-7KQ42-0AA0 is the functional successor — same 250 A, 4-pole class, but with the ETU860 electronic trip and communication built in. The mounting hole pattern and bus-bar spacing are standard for this frame size, but verify the lug kit compatibility if your panel uses an older termination style.