The Siemens 3VA1150-6EF36-0CH0 is a SENTRON molded case circuit breaker (MCCB) rated 50 A continuous at 40 °C, with a 220 kA interrupting capacity at 240 V. That 220 kA figure drops to 154 kA at 415 V and 121 kA at 440 V, then to 17 kA at 500 V and 690 V — the high-end fault clearing is concentrated at the lower voltages typical of North American 240/480 V distribution. This is a line-protection design (not motor-protection), 3-pole, with an undervoltage release (UVR) built in and provision for 2 auxiliary switches plus a trip alarm switch.
The 220 kA SCCR at 240 V puts this in the high-interrupting category — it can handle faults right at the transformer secondary or a large service entrance without cascading upstream. At 415 V (common IEC distribution) the 154 kA still covers most industrial main-breaker positions. The drop to 17 kA above 500 V means it is not intended for 690 V main feeders; at that voltage it is a sub-feed or branch device.
Thermal performance and panel integration
Above 50 °C it drops linearly to 45 A at 70 °C. Maximum power loss is 17.1 W, which matters for heat buildup in a sealed enclosure. Dimensions: 76.2 mm wide (3 in), 130 mm tall, 70 mm deep — standard MCCB footprint for a 3-pole frame this size.