Product Overview and Key Ratings
The Siemens SENTRON 3VA1225-6EF32-0BA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, with a continuous current Iu of 250 A and a rated insulation voltage Ui of 800 V. The TM240 overcurrent release provides thermal-magnetic protection, and the unit includes an undervoltage release (UVR) as the auxiliary release. Breaking capacity is specified at 220 kA at 240 V, 154 kA at 415 V, 36 kA at 440 V, and 17 kA at 690 V — these figures indicate the maximum fault current the breaker can safely interrupt at each voltage level, which is critical for verifying coordination with upstream protective devices.
Thermal Derating and Ambient Temperature
The breaker carries its full 250 A rating from 40 °C through 50 °C ambient. Above 55 °C, the continuous current must be derated: 243.3 A at 55 °C, 236.5 A at 60 °C, 229 A at 65 °C, and 223 A at 70 °C. For panel builders, this means the breaker can be installed in a warm enclosure without losing capacity, as long as the derating curve is applied. The operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Physical Dimensions and Panel Integration
Dimensions are 105 mm wide, 158 mm high, and 70 mm deep. The front face carries an IP40 protection rating, suitable for installation in a standard IP54 or higher enclosure where the breaker is not directly exposed to water jets. The unit does not include auxiliary contacts or a trip indicator, and no communication function is built in. For applications requiring remote status, an auxiliary trip accessory (order code 3VA9608-0BB11) is available as a separate component.