What this MCCB carries and where it fits
The Siemens SENTRON 3VA2225-5JQ32-0JH0 is a 3-pole molded case circuit breaker (MCCB) rated for 250 A continuous current, built around the ETU560 electronic trip unit. It is configured for line protection — meaning it guards the feeder, not a motor branch — and ships with a shunt trip (STL) release and a communication function for remote status. The 187 kA breaking capacity at 240 V tells you it handles high available fault current at low voltage; at 415 V it still interrupts 121 kA, so it suits main or large sub-feed breakers in industrial switchboards where the transformer is close. The IP40 front protection means it is fine inside a dry enclosure but not exposed to washdown.
Derating and thermal reality — the 250 A frame under load
The 3VA2225 frame holds 250 A from 40 °C through 50 °C ambient without derating. At 55 °C it drops to 238 A, at 60 °C to 225 A, at 65 °C to 213 A, and at 70 °C to 200 A. If your panel ambient runs above 50 °C — common in a packed enclosure with upstream breakers — you need to size the load or the breaker accordingly. The maximum power loss is 48 W, which contributes to the internal heat rise; factor that into your enclosure ventilation calcs. Operating range spans -25 °C to 70 °C, storage from -40 °C to 80 °C.
Trip unit and auxiliary configuration
The ETU560 electronic trip unit provides adjustable long-time, short-time, instantaneous, and ground-fault protection. Ground-fault monitoring uses summation current formation on the L-conductor — it sums the phase currents to detect imbalance. The breaker includes a voltage trigger and a trip indicator. Auxiliary contacts are configured as 2 auxiliary switches plus 1 trip alarm switch (HQ). The integrated shunt trip (STL) allows remote tripping; the basic switch variant is 3VA2225-5JQ32-0AA0, and the auxiliary trip module is 3VA9688-0BL32. No undervoltage release or phase failure detection is fitted on this order code.