Siemens 3VA2325-5MN32-0BL0 — 250 A SENTRON MCCB for Motor Protection
The Siemens 3VA2325-5MN32-0BL0 is a SENTRON molded case circuit breaker (MCCB) rated at 250 A continuous current across the full 40 °C to 70 °C ambient range — no derating needed up to 70 °C. It is a 3-pole unit designed specifically for motor protection, with integrated phase failure detection and an undervoltage release (UVR) as the auxiliary release. The breaker carries a breaking capacity of 187 kA at 240 V AC, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V — so it handles high-fault utility feeds or transformer secondaries down to the motor branch. The auxiliary switch complement is 2 auxiliary switches + 1 trip alarm switch + 1 electrical alarm switch, giving you status feedback for the PLC or HMI without adding external contact blocks.
Breaking Capacity and Fault Interruption
The 187 kA at 240 V is the highest short-circuit rating on this breaker — it safely interrupts faults up to that level without cascading upstream. At 415 V and 440 V it still holds 121 kA, which covers most European and Asian industrial distribution voltages. At 690 V the capacity drops to 7.5 kA, so if your panel runs a 690 V motor circuit with high available fault current, verify the SCCR at that voltage against your transformer rating. The trip indicator gives a visual flag after a fault event, speeding up troubleshooting on the line.
Motor Protection Features and Auxiliary Configuration
This breaker is purpose-built for motor protection, meaning its thermal-magnetic or electronic trip curve is shaped for motor inrush and overload profiles. Phase failure detection is built in — if one phase drops, the breaker trips to prevent single-phasing a motor, which would burn the winding. The undervoltage release (UVR) drops the breaker on a brownout or power loss, so motors don't restart unexpectedly when power returns. The auxiliary switch block provides 2 N.O./N.C. auxiliary contacts, 1 trip alarm contact (flags a fault trip vs manual open), and 1 electrical alarm switch — enough for remote status monitoring without extra wiring.
Dimensions and Panel Fit
The breaker measures 248 mm high, 138 mm wide, and 110 mm deep. The 110 mm depth includes the handle and terminals — it fits standard 400 mm deep enclosures with room for wiring gutters. Width of 138 mm is typical for a 3-pole 250 A MCCB; leave at least 25 mm side clearance for heat dissipation and arc-chamber venting per Siemens mounting guidelines.
Power Loss and Thermal Management
Maximum power loss is 40 W at full rated current. In a sealed, non-ventilated enclosure with multiple breakers, sum the power losses and check the enclosure's dissipation rating — 40 W per breaker adds up in a multi-circuit panel. The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C.