What this MCCB is and what the ratings mean
The Siemens 3VA2063-5HN32-0JH0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection — meaning it sits at the feeder or main distribution point, not on a specific motor or load branch. It's a 3-pole unit rated for 63 A continuous current across the full 40 °C to 70 °C ambient range, so no derating needed if your panel runs hot. The interrupting rating is the headline: 187 kA at 240 V AC, 121 kA at 415 V and 440 V, dropping to 75.6 kA at 500 V and 3 kA at 690 V. That 187 kA at 240 V tells you this breaker handles high available fault current — typical for a main service entrance or a large distribution panel where the utility transformer is close. The 63 A frame with that interrupting capacity means you're buying fault-current headroom, not just load current.
Auxiliary and trip options built in
Factory-fitted with 2 auxiliary switches plus 1 trip alarm switch (HQ type), and a shunt trip release (STL). That means you get remote status indication (open/closed/tripped) and remote trip capability without adding external modules. The shunt trip lets a safety PLC or E-stop circuit kill the breaker directly — useful for emergency-off chains or remote shutdown. No undervoltage release on this variant, so if you need UVR for undervoltage protection, this isn't the one. Power loss is 5.4 W maximum, negligible for panel heat budgeting.
Physical fit and panel integration
Dimensions: 105 mm wide, 181 mm high, 86 mm deep. That's a standard 3-pole MCCB footprint for the SENTRON 3VA2 frame — mounts on a DIN rail or direct panel-mount via the screw terminals. The 86 mm depth includes the handle and terminals; check your enclosure depth if you're retrofitting into a shallow panel. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C, so it's fine for unheated electrical rooms or outdoor enclosures in moderate climates.