What this MCCB is and what it does
The Siemens SENTRON 3VA2163-7MS32-0AG0 is a 3-pole molded case circuit breaker (MCCB) rated for 63 A continuous current, configured as a starter protection version — meaning it is built to protect motor branch circuits against short-circuit and overload, with the ETU310M electronic trip unit handling the overcurrent release. Breaking capacity is the headline number here: 330 kA at 240 V, 242 kA at 415 V and 440 V, 187 kA at 500 V, and 52.5 kA at 690 V. That 330 kA figure at 240 V means this breaker can safely interrupt a fault current up to 330,000 A without failing — critical for high-fault installations like large transformer secondaries or industrial distribution panels where available fault current is high. Rated insulation voltage is 800 V, so the breaker is rated for use on 690 V systems with margin. Maximum power loss is 75 W — a figure to check against enclosure thermal dissipation if the panel is tightly packed.
Thermal derating and operating limits
The 63 A rating holds flat from 40 °C through 50 °C ambient. At 55 °C it derates to 60.48 A, at 60 °C to 59.22 A, at 65 °C to 57.96 A, and at 70 °C to 56.7 A. If the panel ambient runs above 50 °C, the continuous load must be reduced accordingly — a common oversight when sizing for non-air-conditioned enclosures. Operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The storage range is wider because the breaker is not dissipating heat when stored — handling, not running, is what that limit governs.
Physical fit and auxiliary wiring
Dimensions: 105 mm wide, 181 mm high, 86 mm deep. The 105 mm width is the standard 3-pole MCCB footprint for this SENTRON frame size — verify the DIN-rail or mounting-plate spacing against the existing panel layout before ordering. Auxiliary contact configuration is 1 auxiliary switch + 1 trip alarm switch (HP version). The supplied basic switch is order code 3VA2163-7MS32-0AA0, and the integrated auxiliary trip is 3VA9608-0BB11. No undervoltage release, no ground-fault monitoring, no communication function, no phase-failure detection — this is a straight thermal-magnetic-plus-electronic-trip breaker with basic signaling. Trip indicator is present — a mechanical flag that shows the breaker tripped on fault versus being manually switched off, which speeds fault isolation on the line.