Siemens SENTRON 3VA2225-8JP32-0AA0 — 250 A Line-Protection MCCB with ETU550 Trip Unit
The Siemens SENTRON 3VA2225-8JP32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection at 250 A continuous current, with an ETU550 electronic trip unit. Its interrupting capacity reaches 440 kA at 240 VAC, 330 kA at 415 VAC and 440 VAC, 220 kA at 500 VAC, and 52.5 kA at 690 VAC — covering high-fault utility feeds and large motor branch circuits where the available short-circuit current is substantial. The ETU550 is a microprocessor-based release that provides adjustable long-time, short-time, instantaneous, and ground-fault protection curves, plus communication capability via the onboard communication function. This makes the breaker suitable for integration into power-monitoring and energy-management systems without an external add-on module. Rated insulation voltage is 800 V, and the breaker's power loss at full load is 48 W maximum — a figure to consider for thermal management inside a closed panel. The IP40 rating on the front means the breaker face is protected against solid objects over 1 mm but not sealed against moisture; panel builders should plan for an IP54 or higher enclosure if washdown or outdoor installation is required.
Current Derating and Thermal Management
The 3VA2225-8JP32-0AA0 is rated for 250 A continuous up to 50 °C ambient. Above that, derating applies: 238 A at 55 °C, 225 A at 60 °C, 213 A at 65 °C, and 200 A at 70 °C. The maximum operating ambient temperature is 70 °C, with storage extremes from -40 °C to 80 °C. For a panel designer, this means the breaker can be installed in a non-air-conditioned electrical room or near a heat source, as long as the continuous load is adjusted per the ambient curve.