What it is and what it does
The Siemens 3VA2325-5MN32-0DA0 is a SENTRON molded case circuit breaker (MCCB) designed specifically for motor protection. It carries a continuous current rating of 250 A across the full ambient temperature range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel thermal budgeting. The 3-pole unit integrates an undervoltage release (UVR) and phase failure detection, so it can drop the motor on loss of phase or a sag below the release threshold. Breaking capacity is 187 kA at 240 V AC, tapering to 121 kA at 415/440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V. That 187 kA at 240 V is a high-interrupting rating — it handles fault currents from large transformers or parallel-fed buswork without needing a current-limiting fuse upstream. The 7.5 kA at 690 V still covers most 690 V motor branch circuits in industrial plants.
Panel fit and integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep — a standard MCCB footprint for a 250 A frame. The 110 mm depth (4.33 in) is shallow enough for most 300 mm deep enclosures with room for rear bus connections. Mounting is via screw-clamp or optional DIN-rail adapter; the 138 mm width occupies three 45 mm pole spaces on a DIN rail. Maximum power dissipation is 40 W at rated load — that heat needs to be factored into the enclosure's thermal rise calculation, especially in a sealed stainless steel panel on a washdown line. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Motor protection specifics
The design is explicitly for motor protection, meaning the trip curve and thermal memory are tuned for motor inrush and overload profiles rather than straight cable protection. Phase failure detection is built in — it will trip on loss of one phase, preventing single-phasing damage to the motor. The undervoltage release (UVR) is a separate auxiliary release that can be wired to a safety circuit or E-stop chain to drop the breaker on command. The basic switch variant is 3VA2325-5MN32-0AA0 — this is the internal switching mechanism. The 3VA2325-5MN32-0DA0 adds the undervoltage release and the motor protection trip unit. No auxiliary switch is fitted as standard; if you need a status contact for the PLC, you will add an external auxiliary switch block.