What this MCCB delivers on the critical path
The Siemens 3VA1163-5EF36-0KA0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated 63 A continuous at 40 °C, designed for line protection. Its TM240 thermal-magnetic release handles overload and short-circuit response without external control power. The integrated shunt trip (STL) auxiliary release lets a remote signal or safety relay trip the breaker independently of the overcurrent element — useful for emergency-stop circuits or supervisory shutdown sequences that have to land inside the outage window.
Interrupting capacity — selectivity headroom
At 240 V the breaker interrupts 187 kA; at 415 V it still clears 121 kA. That SCCR gives the panel designer headroom for high-fault utility feeds without cascading upstream — the breaker clears the fault before the main device sees it. For 500 V and 690 V systems the rating drops to 17 kA, which still covers most industrial distribution transformers up to that voltage class.
Thermal derating — what the 63 A rating actually means
The 63 A rating holds flat from 40 °C to 50 °C. At 55 °C it derates to 62 A, at 65 °C to 60 A, and at 70 °C to 58 A. If the panel ambient runs above 50 °C, the continuous load must be reduced accordingly — the breaker does not trip falsely, but the TM element's thermal characteristic shifts with enclosure temperature.
Panel fit — dimensions and mounting
The breaker measures 130 mm high, 76.2 mm wide, 70 mm deep — a 3-pole MCCB footprint that drops into standard SENTRON mounting plates or DIN-rail adapters. The 70 mm depth leaves clearance for rear-connected busbars or cable lugs in a 200 mm deep enclosure.