Line Protection MCCB with 187 kA Interrupting Capacity
The Siemens SENTRON 3VA1225-5EF32-0CH0 is a 3-pole molded case circuit breaker rated for 250 A continuous current with a TM240 thermal-magnetic overcurrent release. Its interrupting capacity hits 187 kA at 240 V and 121 kA at 415 V, which means it can clear high-fault-current events without cascading upstream — critical for main feeders or high-capacity distribution panels where the available fault current is substantial. The line protection variant omits ground-fault sensing and communication, keeping it a straightforward, non-communicating breaker for standard overcurrent protection duty.
Thermal Derating and Operating Envelope
The breaker carries its full 250 A rating from 40 °C up through 50 °C ambient (–). Above that, derating begins: 243.3 A at 55 °C, 236.5 A at 60 °C, 229 A at 65 °C, and 223 A at 70 °C (–). For a panel running warm — say a packed enclosure near a furnace line or in a non-climate-controlled electrical room — that derating curve is the number to size against, not the 250 A nameplate. The operating temperature range spans -25 °C to 70 °C (–), with storage from -40 °C to 80 °C (–).
Integrated Undervoltage Release and Auxiliary Switching
This order code ships with an undervoltage release (UVR) factory-installed. The UVR trips the breaker when supply voltage drops below a threshold — common for motor branch circuits where a brownout could stall a load and cause a locked-rotor condition. The auxiliary contact block provides 2 auxiliary switches plus 1 trip alarm switch HQ, giving status feedback for PLC or SCADA monitoring without an add-on module. The trip indicator gives local visual confirmation of a fault trip.
Physical Fit and Panel Integration
Dimensions are 105 mm wide, 158 mm high, and 70 mm deep (–). Front face carries IP40 protection — suitable for enclosed panel mounting where no water ingress is expected. The 3-pole form factor fits standard SENTRON mounting bases; the 70 mm depth leaves clearance in shallow enclosures. Latching endurance is rated at 15,000 operations, which covers frequent switching in process control or machine-tool applications without early mechanical wear.