What this MCCB is and what the ratings mean for fit
The Siemens 3VA2063-6HN36-0AA0 is a SENTRON 3VA2 molded case circuit breaker (MCCB) in the line protection version, carrying a continuous current rating Iu of 63 A that holds flat from 40 °C through 70 °C — no derating needed across typical panel ambient temperatures. Breaking capacity is the headline selector: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3 kA at 690 V. The 242 kA figure at 240 V means this breaker handles very high available fault current on the low-voltage side of a step-down transformer — typical for large commercial or industrial service entrances where the utility transformer is close-coupled. The ETU350 electronic trip unit gives adjustable long-time, short-time, instantaneous, and ground-fault protection curves — this is not a fixed thermal-magnetic; it is a programmable release that lets the engineer coordinate selectively with downstream breakers.
Panel fit and physical integration
Footprint is 105 mm wide by 181 mm tall by 86 mm deep — the 105 mm width is a standard 3-pole MCCB form factor for the 3VA2 frame, so it drops into existing panel cutouts sized for that frame without re-drilling the mounting plate. Front protection is IP40, meaning tools and fingers are kept out but the breaker is not sealed against water ingress — suitable for indoor panel mounting, not washdown environments. Rated insulation voltage Ui is 800 V, so the internal clearances and creepage distances are designed for 690 V systems with margin.