MCCB with ETU350M — what the ratings mean for panel fit
The Siemens 3VA2325-5MN32-0KC0 is a SENTRON 3VA2 molded case circuit breaker rated 250 A continuous (Iu) in a 3-pole configuration, carrying an ETU350M electronic trip unit. The interrupting ratings climb to 187 kA at 240 V, then taper to 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V — a curve that tells you this breaker is sized for high-fault industrial distribution, not light commercial service. At 690 V the 17 kA figure still clears most motor-circuit faults, but verify your available fault current against that value before committing the BOM line. Thermal derating is published: full 250 A through 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 ambient runs above 50 °C, the continuous load must be reduced accordingly — a common oversight during summer commissioning in non-conditioned enclosures. The 3VA2 frame accepts a shunt trip (STL) release and includes 2 HQ auxiliary switches as standard. There is no undervoltage release, no ground-fault module, and no communication function on this variant — it is a straight thermal-magnetic-plus-electronic protection device for dedicated overcurrent and short-circuit duty.
Lifecycle and sourcing reality — active, not orphaned
The basic switch (the internal switching mechanism) is order code 3VA2325-5MN32-0AA0, and the integrated auxiliary trip is 3VA9688-0BL33 — both are serviceable sub-assemblies if a field repair ever needs to swap the trip unit without replacing the entire breaker.
Integration — panel footprint and wiring
The 3VA2325-5MN32-0KC0 measures 248 mm high, 138 mm wide, and 110 mm deep — a standard 3-pole MCCB footprint that fits most low-voltage switchgear cubicles and distribution panels without re-drilling the mounting plate. Depth of 110 mm leaves clearance for rear-connection busbars or cable lugs. Maximum power loss is 37.5 W — relevant for thermal budgeting inside a sealed enclosure. The storage range spans -40 °C to 80 °C; operating range is -25 °C to 70 °C. Phase-failure detection is built into the ETU350M trip unit, so no external phase-loss relay is needed for motor protection applications.