The Siemens 3VA1163-5EF36-0KC0 is a SENTRON 3-pole molded case circuit breaker rated for 63 A continuous at 40 °C, with a TM240 thermal-magnetic release. It carries a massive 187 kA interrupting capacity at 240 V, dropping to 121 kA at 415 V and 75.6 kA at 440 V — numbers that tell you this breaker is built for high-fault industrial distribution, not light commercial service. At 63 A continuous, this is a line-protection breaker — not a motor-protection device with adjustable overloads.
Comes with 2 auxiliary switches (HQ type) pre-installed, so you get status feedback without adding a separate accessory block.
Rated 63 A from 40 °C up to 50 °C, then derates gradually: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. Maximum power loss is 17.3 W at full load. That's the heat you need to evacuate from the enclosure — relevant for sealed panels or high-density layouts where thermal stacking could push the ambient past the derating curve.