Siemens 3VA2325-5MN32-0AF0 — 250 A SENTRON MCCB with ETU350M Release
The Siemens 3VA2325-5MN32-0AF0 is a SENTRON 3-pole molded case circuit breaker rated for 250 A continuous current, fitted with an ETU350M electronic overcurrent release and configured for motor protection duty. It carries a 187 kA interrupting capacity at 240 V, with the curve dropping to 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V — so the fault-clearing headroom at typical 400 V-class distribution voltages is well above what most downstream panels will ever see, which simplifies selective coordination studies.
Thermal Derating and Continuous Current
The breaker holds its full 250 A rating from 40 °C through 50 °C ambient. At 55 °C it derates to 240 A, at 60 °C to 235 A, at 65 °C to 230 A, and at 70 °C to 225 A. If the panel ambient runs hot — say, a packed enclosure with multiple breakers — the 55 °C and above figures are the ones that govern the load you can actually protect, not the 250 A nameplate. Maximum power loss is 37.5 W, which factors into enclosure thermal calculations.
Motor Protection and Release Configuration
This is the motor protection version of the 3VA2 frame, meaning the ETU350M release is set up for the higher inrush and thermal memory that motor starting demands. Phase failure detection is built in — it will trip on a lost phase before single-phasing damages the load. The auxiliary contact package includes one auxiliary switch and one trip alarm switch (HQ type), so you get both a status signal and a separate fault indication without adding an external relay. No undervoltage release, no ground-fault monitoring, no communication module on this variant.
Mounting and Integration
Dimensions are 248 mm tall by 138 mm wide by 110 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without re-drilling. The 800 V rated insulation voltage (Ui) gives headroom for 690 V systems. Mechanical endurance is rated at 15,000 cycles, which is typical for a motor-protection breaker in a panel that sees regular switching.