What it is and what it does
The Siemens 3VA1063-3ED32-0HH0 is a SENTRON molded case circuit breaker (MCCB) built for line protection — the kind of breaker that sits between your transformer and the distribution bus, not the one you hang a motor starter off of. It's a 3-pole unit rated 63 A continuously at 40 °C, and it holds that rating all the way up to 50 °C before it starts to taper: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. That's a solid thermal curve for a warm panel — you don't lose headroom until you're past 55 °C.
Breaking capacity — the number that decides whether it clears a fault or welds shut
This MCCB carries a breaking capacity of 75.6 kA at 240 V AC, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V. That 75.6 kA at 240 V is a big number — it means this breaker can interrupt a fault current that high without self-destructing, which is what you need when the utility transformer is sitting right outside the building. At 690 V the 7.5 kA figure is lower, but that's still enough for most industrial feeders at that voltage level. The rated insulation voltage is 800 V, so the internal creepage and clearance are specced for 690 V systems with margin.
What's inside the can — auxiliary switches and releases
This version ships with 2 auxiliary switches plus a trip alarm switch (the HQ designation), and a shunt trip release (STL) for remote tripping. No undervoltage release, no ground-fault monitoring, no communication module. If your panel needs a UVR or GFCI function, you're looking at a different suffix. The shunt trip lets a safety PLC or E-stop circuit kill the breaker remotely — that's the usual integration point.
Panel fit — dimensions and integration
The can measures 130 mm tall, 76.2 mm wide, and 70 mm deep. That 76.2 mm width is three inches, which is the standard MCCB footprint for a 3-pole frame this size — it fits the usual panel-mount cutout and bus-bar spacing. Depth of 70 mm means it clears most enclosure back-panels without a gland-plate conflict. Mounting is screw-clamp or bus-bar, not DIN rail.