Motor protection MCCB with ETU350M release
The Siemens SENTRON 3VA2450-7MN32-0KL0 is a 3-pole molded case circuit breaker rated for 500 A continuous current (Iu) at 40 °C, designed specifically for motor protection duty. It carries the ETU350M electronic overcurrent release, which provides adjustable thermal-magnetic protection curves suited to motor starting profiles and phase-failure detection. The breaker maintains its full 500 A rating up to 50 °C ambient; above that it derates linearly to 480 A at 70 °C, so panel placement and ventilation matter when the breaker is near other heat sources.
Breaking capacity across voltage levels
This MCCB delivers 330 kA breaking capacity at 240 V, 242 kA at 415 V and 440 V, and 52.5 kA at 690 V. Those figures cover most industrial distribution voltages in IEC markets. The 242 kA at 415 V is high enough for main incoming positions in large switchboards; the 52.5 kA at 690 V suits wind-turbine or mining applications where the line-to-line voltage is higher than standard 400 V distribution.
Auxiliary and trip configuration
The breaker ships with 2 auxiliary switches plus 1 trip alarm switch and 1 electrical alarm switch (HQ type), giving four discrete signal contacts for remote status monitoring. A shunt trip (STL) is integrated for remote tripping; the supplied basic switch is order code 3VA2450-7MN32-0AA0, and the integrated auxiliary trip is 3VA9688-0BL33. There is no undervoltage release, no ground-fault monitoring, and no communication module on this variant — it is a standalone motor-protection breaker, not a networked power meter.
Environmental and mechanical limits
Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The front face carries IP40 protection — suitable for enclosed panel mounting where the breaker is not exposed to dust or moisture ingress. Maximum power loss is 99 W, which should be factored into enclosure thermal calculations. Mechanical latching endurance is rated at 15 000 operations.
Physical dimensions and panel fit
Dimensions are 248 mm height, 138 mm width, 110 mm depth. The 138 mm width is standard for a 3-pole frame in the SENTRON 3VA2 series, so it fits existing mounting footprints and busbar systems designed for that form factor. Rated insulation voltage is 800 V (Ui), confirming the breaker is rated for 690 V line-to-line systems with margin.