63 A MCCB with a flat thermal curve and a 330 kA interruption at 240 V
The Siemens 3VA2163-7KQ46-0AA0 is a 4-pole SENTRON molded case circuit breaker rated for 63 A continuous current, and it holds that 63 A rating flat from 40 °C all the way up to 70 °C — no derating to calculate when the panel runs hot. The interrupting capacity at 240 V is 330 kA, which drops to 242 kA at 415 V and 440 V, then to 187 kA at 500 V, and finally to 3.7 kA at 690 V. That 330 kA figure at 240 V tells you this breaker is built for high-fault locations like a main disconnect on a large distribution transformer or a service entrance where available fault current is well above what a standard 65 kA or 100 kA MCCB can handle.
What the ratings mean for fit
The ETU860 electronic overcurrent release gives you adjustable long-time, short-time, instantaneous, and ground-fault protection curves — this is not a thermal-magnetic breaker; it's a programmable trip unit that lets you coordinate selectively with downstream feeders. The communication function (listed as present on this variant) means it can talk to a higher-level system for power monitoring and remote trip indication, which saves a maintenance electrician from having to walk the whole line to find what opened. The ground-fault monitoring uses summation current formation on L + N, so it catches leakage on the neutral as well as the phases. Power loss is 4 W maximum, which is low enough that you don't need to factor heat into the enclosure sizing for a single breaker.
Deployment context
This breaker is a panel-mounted device — it bolts into a switchboard or a distribution panel, not onto a DIN rail. With an IP40 rating on the front, it is protected against tools and solid objects larger than 1 mm, but it is not washdown-rated; keep it inside a dry enclosure or a climate-controlled electrical room. The 4 W power loss at rated load is negligible, so you do not need forced ventilation for this single unit, but cluster several breakers together and the cumulative heat matters.