What the interrupting ratings mean on this MCCB
The Siemens SENTRON 3VA2063-6KP36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 63 A continuous current across the full 40 °C to 70 °C ambient range — no derating needed as the panel warms up. Its interrupting capacity hits 242 kA at 240 V and 187 kA at 415 V, which puts it squarely in the high-fault-current class for large transformer secondaries or busway taps where available fault current runs high. At 690 V it still clears 3 kA, enough for most motor branch circuits on 690 V systems. That 242 kA figure at 240 V means it can sit at the main of a 240 V switchboard without needing a current-limiting fuse upstream — it handles the full fault itself.
ETU850 trip unit and selectivity
This breaker carries the ETU850 electronic trip unit, which gives you adjustable long-time delay (tr) from 0.5 s to 25 s and a short-time delay (tsd) up to 0.5 s. The instantaneous pickup (Ii) is fixed at 10 times the rated current. In a distribution panel, those adjustable time bands let you coordinate downstream breakers — the 3VA holds in during a transient fault on a feeder, letting the branch breaker clear it first. That's selectivity without oversizing the main. The 800 V rated insulation voltage (Ui) covers 480 V and 600 V class systems with margin.
Panel fit and communication
At 105 mm wide, 181 mm tall, and 86 mm deep, it fits a standard MCCB footprint on a DIN rail or panel-mount base. The IP40 front protection means it's fine in a closed enclosure — no washdown rating, so keep it behind the gland plate. It has a communication function onboard, which on this SENTRON platform typically means it can talk to a power monitoring system via a communication module (not included) for remote trip indication and current metering. Power loss is 5.4 W max — negligible for panel thermal calculations.
How it compares to the 5SQ2370-2YA05
The 5SQ2370-2YA05 is a functionally similar Siemens MCCB in the same SENTRON family, but it's an older generation with a different trip unit and no communication capability. The 3VA2063-6KP36-0AA0 replaces it in new designs — same 3-pole 63 A frame, but with the ETU850 electronic trip and communication interface. If you're swapping out a 5SQ2370-2YA05 in an existing panel, check the mounting hole pattern and bus bar spacing; the 3VA shares the same 105 mm width and 86 mm depth, so it should drop in without rewiring, but verify the lug kit compatibility. The interrupting ratings on the 3VA are higher across the board.