What this MCCB carries — and where the ratings matter
The Siemens SENTRON 3VA2325-5HN32-0BL0 is a 3-pole molded case circuit breaker (MCCB) rated for a continuous current Iu of 250 A, fitted with the ETU350 electronic trip unit for line protection. Breaking capacity is 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V — so the same breaker handles high-fault commercial mains and lower-fault industrial distribution without swapping frames. The ETU350 gives adjustable long-time, short-time, instantaneous, and ground-fault protection curves, which makes selectivity coordination with downstream breakers feasible on a mixed-load panel. Current derating is published per ambient temperature: 250 A up to 50 °C, then 240 A at 55 °C, 235 A at 60 °C, 230 A at 65 °C, and 225 A at 70 °C. If the panel runs hot — say a sealed enclosure near a furnace line — the 55 °C column is the one you size against, not the 40 °C headline. The auxiliary contact block ships with 2 auxiliary switches, 1 trip alarm switch, and 1 electrical alarm switch (HQ version). An undervoltage release (UVR) is integrated as the auxiliary release design. No communication function or phase-failure detection is built in — this is a standalone line-protection breaker, not a power-monitoring device.
Panel fit and mounting
Dimensions: 138 mm wide, 248 mm high, 110 mm deep. The 138 mm width is the three-pole footprint — check your existing busbar or mounting plate spacing if replacing a different MCCB family. The 110 mm depth includes the rotary handle; clearance behind the panel for the arc chamber must be maintained per the manufacturer's installation instructions.