The Siemens 3VA2450-7MN32-0CH0 is a SENTRON molded case circuit breaker (MCCB) built for motor protection, rated 500 A at 40 °C and carrying a breaking capacity of 330 kA at 240 V. It is a three-pole unit with an undervoltage release, phase failure detection, and a trip indicator — the kind of protection package you want on a pump or compressor motor where a single-phase condition could cook the winding before the overload relay trips.
Breaking capacity across the voltage range
At 240 V it interrupts 330 kA, dropping to 242 kA at 415 V and 440 V, then 187 kA at 500 V, and 15.3 kA at 690 V. That 690 V figure is the one to watch if this breaker is specified on a 690 V motor circuit — 15.3 kA is still substantial but well below the low-voltage ratings, so verify the available fault current at the panel.
Current rating and thermal derating
Full 500 A holds from 40 °C through 50 °C — no derating needed in most panel environments. At 55 °C it drops to 495 A, then 490 A at 60 °C, 485 A at 65 °C, and 480 A at 70 °C. The operating temperature range is -25 °C to 70 °C, with storage down to -40 °C and up to 80 °C. Max power loss is 101.5 W, so factor that into your enclosure thermal budget if the panel is densely packed.
Dimensions and mounting
The breaker measures 248 mm tall, 138 mm wide, and 110 mm deep. That depth is the critical dimension for shallow backpanel enclosures — 110 mm is about 4.33 inches, so it fits in standard 6-inch-deep cabinets with room for wiring behind it. Width of 138 mm (5.43 in) is typical for a 500 A frame; check the gland plate knockout spacing if retrofitting into an existing panel.
Auxiliary and release configuration
Factory-fitted with 2 auxiliary switches plus a trip alarm switch (HQ type), and an undervoltage release (UVR). The UVR will drop the breaker if control power is lost — useful for emergency-stop circuits where you want the breaker to open on a safety signal, but be aware it means the breaker cannot be reclosed until control voltage is restored. The trip alarm switch gives a separate signal when the breaker trips on fault, which can feed a PLC input for remote fault annunciation.
Time-current characteristics
The short-time withstand rating is 6 kA limited to 1 second. The minimum tripping time is 4 s and maximum is 13 s — these are likely the thermal-magnetic or electronic trip curve bands. For motor starting applications, the 4 s minimum gives enough time for a standard induction motor start under load without nuisance tripping.