What this MCCB carries — the ratings that decide fit
The Siemens 3VA2063-5HL36-0BL0 is a 3-pole SENTRON molded case circuit breaker rated for 63 A continuous current at 40 °C, with an interrupting capacity of 187 kA at 240 V. That 187 kA figure drops to 121 kA at 415 V and 440 V, then to 79 kA at 500 V, and 3.4 kA at 690 V — so at typical 400 V distribution levels, it still clears 121 kA of fault current without the breaker welding itself shut. The ETU320 electronic trip unit handles the curve shaping and coordination. Rated insulation voltage sits at 800 V, meaning the internal clearances and creepage are sized for 690 V systems with margin. The breaker holds its full 63 A rating from 40 °C up through 50 °C; it starts derating above that — 60.6 A at 55 °C, 58.3 A at 60 °C, down to 53.6 A at 70 °C. If the panel ambient runs hot, factor that derate into the load calculation. This is a line-protection version — no voltage trigger, no phase-failure detection, no communication module. It's built to sit on the incoming feeder or a heavy branch circuit and clear faults on overcurrent alone. The auxiliary contact block carries 2 auxiliary switches plus 1 trip alarm and 1 electrical alarm switch (HQ version), so the PLC gets a clean status signal on trip without extra wiring.
Panel fit and mounting
Dimensions are 105 mm wide by 181 mm tall by 86 mm deep — standard SENTRON 3VA2 frame footprint. Bolts into the enclosure backplate on a 3-pole base; no DIN-rail clip on this frame class. The undervoltage release (UVR) is factory-integrated (order code 3VA9608-0BB11), so if the control voltage drops, the breaker trips without a separate shunt-trip module taking up panel real estate.