What this MCCB carries — and what it doesn't
The Siemens SENTRON 3VA2225-8JQ42-0AA0 is a 4-pole molded case circuit breaker rated for 250 A continuous current, designed for line protection in distribution panels. It breaks up to 440 kA at 240 V and still holds 330 kA at 415 V and 440 V — that's serious fault-clearing headroom for a 250 A frame. The thermal derating curve starts at 55 °C (238 A) and drops to 200 A at 70 °C, so if this lands in a hot enclosure, you're not getting the full 250 A out of it without some ventilation planning. Ground-fault monitoring uses summation current formation on L+N conductors — it watches the vector sum, not a separate sensor. That means it catches leakage without needing an external GFCI module, but it also means the neutral must pass through the breaker. No undervoltage release, no voltage trip, no trip indicator on this variant.
Panel fit — dimensions and integration
The 3VA2225-8JQ42-0AA0 measures 140 mm wide, 86 mm deep, 181 mm tall — a standard SENTRON 3VA frame size for this current class. It mounts on a DIN rail or direct panel screw-down, depending on the accessory base ordered separately. The 4-pole width means it occupies the same footprint as a 4-module MCCB in a Siemens distribution board; verify the backpanel cutout against the 140 mm width before slotting it into an existing layout.
Breaking capacity — what the numbers mean for coordination
At 240 V the breaker clears 440 kA — that's the maximum fault current it can interrupt without welding contacts or venting plasma. Drop to 690 V and the breaking capacity falls to 52.5 kA, which is still high for a 250 A frame but tells you the arc extinction is voltage-sensitive. For selectivity studies, the 330 kA at 415 V is the number most European panel builders will use; the 220 kA at 500 V covers 480 V North American systems with headroom. The 48 W maximum power loss at rated current matters for enclosure thermal rise — that's heat that has to leave the cabinet.
Communication function onboard
This variant includes a communication function — the 3VA platform supports PROFIBUS, PROFINET, or Modbus via plug-in modules, though the exact protocol depends on the communication module ordered alongside the breaker. The base breaker ships with the communication-ready interface; the module is a separate order code. If you need remote trip indication, energy metering, or parameterization over a network, this is the right base variant to start from.