Motor protection MCCB with high interrupting capacity
The Siemens SENTRON 3VA2450-5MN32-0KC0 is a 3-pole molded case circuit breaker (MCCB) purpose-designed for motor protection, carrying a continuous current rating of 500 A at 40 °C and derating to 480 A at 70 °C. It delivers a 187 kA interrupting capacity at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 9 kA at 690 V — covering the full range of low-voltage fault currents a motor branch circuit can see. The design includes an integrated shunt trip (STL) and two HQ auxiliary switches, plus phase failure detection, so it drops a motor on loss of phase without a separate relay.
Selectivity and coordination in the panel
This MCCB is part of the SENTRON 3VA2 series, designed for selective coordination with upstream and downstream devices. The 500 A frame size pairs naturally with motor starters in the 200–400 kW range on 400 V supplies, where the 121 kA SCCR at 415 V provides headroom for high-fault installations.