What this MCCB carries and where it fits
The Siemens SENTRON 3VA1225-4EF32-0HA0 is a 3-pole molded case circuit breaker (MCCB) rated for 250 A continuous current at 40 °C, with a TM240 thermal-magnetic overcurrent release designed for line protection. Its breaking capacity reaches 121 kA at 240 V AC and 75.6 kA at 415 V AC — figures that tell you it can interrupt high-fault currents on the secondary side of a distribution transformer or at a main panel feeder without cascading upstream. The rated insulation voltage of 800 V confirms it is built for 480 V and 600 V class systems with margin. This is a line-protection device — meaning it guards cables and busbars against overload and short circuit, not motor or branch-circuit loads that need a different trip curve. The TM240 release gives a fixed thermal pickup at 240 A and a magnetic trip calibrated for the breaker's frame size. For a cold-storage or ammonia refrigeration plant, the 250 A continuous rating at 40 °C ambient is the figure to size against the main feeder; the breaker holds that rating through 50 °C and only begins to derate above 55 °C, dropping to 223 A at 70 °C. That thermal stability matters when the MCCB lives in a warm electrical room adjacent to a freezer.
Breaking capacity across voltages
The interrupting rating drops as system voltage rises: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, 17 kA at 500 V, and 11.9 kA at 690 V (–). For a 480 V panel in a US installation, the relevant figure is the 440 V value (52.5 kA) — sufficient for most distribution boards with available fault current under that threshold. At 690 V the breaker still clears 11.9 kA, which covers many industrial motor-control-center applications in 690 V regions.
Physical fit and panel integration
The 3VA1225-4EF32-0HA0 measures 105 mm wide, 158 mm tall, and 70 mm deep (–). That 105 mm width is the standard 3-pole frame footprint for this SENTRON series — it occupies three 35 mm DIN positions if mounted on a DIN rail, or bolts directly into a panel via the rear mounting plate. Depth of 70 mm leaves room behind a 200 mm deep enclosure for wiring and the shunt trip accessory. The maximum power loss of 57 W means the breaker dissipates heat into the enclosure; factor that into your thermal budget if the panel is sealed or in a high-ambient area.