Siemens 3VA2225-8HN42-0AA0 — 250 A SENTRON MCCB with ETU350 Trip Unit
The Siemens 3VA2225-8HN42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current at 40 °C, with a 4-pole configuration and an ETU350 electronic trip unit. Its interrupting capacity reaches 440 kA at 240 V AC, 330 kA at 415 V, and 220 kA at 500 V — figures that place it in the high-fault-current tier for industrial distribution panels. This MCCB is designed for line protection (feeder duty) in main or branch distribution, where the 250 A frame and the ETU350's adjustable trip curves allow coordination with downstream breakers. The IP40 front protection suits panel-mount installations where the enclosure provides the environmental seal.
Breaking Capacity and Thermal Derating — What the Ratings Mean for Panel Design
The 440 kA at 240 V is the maximum short-circuit current the breaker can safely interrupt at that voltage — a figure that governs SCCR (short-circuit current rating) compliance for the panel. At 690 V the rating drops to 52.5 kA, so verify the available fault current at the point of installation against the voltage-specific curve. Thermal derating is minimal up to 50 °C (full 250 A), then drops to 241 A at 55 °C and 213 A at 70 °C. For a panel with ambient above 50 °C, size the continuous load against the derated value, not the nameplate 250 A. The ETU350 trip unit supports adjustable long-time, short-time, instantaneous, and ground-fault protection (though this variant ships without ground-fault monitoring). Power loss at full load is 48 W maximum — relevant for thermal budgeting in a sealed enclosure.
Physical Fit and Panel Integration
Dimensions: 181 mm height, 140 mm width, 86 mm depth. The 4-pole width (140 mm) matches the standard SENTRON 3VA2 frame footprint for 250 A breakers. Panel cutout and mounting hole pattern are consistent across the 3VA2 family, so a swap with a sibling of the same frame size requires no re-drilling. Storage range -40 to 80 °C; operating range -25 to 70 °C. The 86 mm depth leaves clearance for rear-connected busbars or cable lugs in a standard 200 mm deep enclosure.