The Siemens 3VA1225-4EF32-0JC0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current (Iu) across 3 poles, configured for line protection — meaning it sits at the feeder or main distribution point, not downstream on a motor branch. It carries a TM240 thermal-magnetic overcurrent release, so the thermal pickup is fixed at 250 A and the magnetic trip threshold is 240 A (the TM240 designation). The interrupting ratings climb to 121 kA at 240 V, 75.6 kA at 415 V, 25 kA at 440 V, and 11.9 kA at 690 V — those numbers tell you the fault-clearing capability at each voltage level, and the 415 V figure is the one most European 400 V distribution panels care about. This MCCB includes a shunt trip (STL) auxiliary release for remote tripping, plus 2 auxiliary switches (HQ type) for status feedback to a PLC or panel lamp. It does not carry undervoltage release, phase failure detection, ground fault monitoring, or communication functions — it is a straightforward thermal-magnetic breaker with a voltage-trigger capability. The front face is rated IP40, so it is protected against tools and small wires entering the enclosure but not against water ingress; mount it inside a panel, not in a washdown zone.
Thermal derating and endurance
The 250 A continuous rating holds flat from 40 °C to 50 °C ambient — no derating needed in a typical 40 °C panel. Above that, it steps down: 243.3 A at 55 °C, 236.5 A at 60 °C, 229 A at 65 °C, and 223 A at 70 °C. If your panel runs hot (e.g., inside a non-ventilated enclosure near transformers), use the 55 °C or 60 °C figure for sizing; the breaker will still carry load but at a reduced limit. Mechanical endurance is rated at 15,000 operations — that is the latching endurance, not the electrical endurance under load, so it is fine for infrequent switching but not a daily disconnect.
Physical fit and integration
The 3VA1225-4EF32-0JC0 measures 70 mm deep, 105 mm wide, and 158 mm tall. The 105 mm width is the standard 3-pole MCCB footprint for this SENTRON frame — it occupies three 35 mm DIN-rail modules (3 x 35 mm). Depth of 70 mm means it will clear most standard enclosure backplates and gland plates, but check the busbar or cable entry clearance if you are retrofitting into a shallow panel. The storage temperature range (-40 °C to 80 °C) and operating range (-25 °C to 70 °C) cover most indoor and unheated warehouse conditions.