The Siemens SENTRON 3VA1050-4ED32-0HC0 is a 3-pole molded case circuit breaker rated for 50 A continuous at 40 °C, with a breaking capacity that starts at 121 kA at 240 VAC and drops to 11.9 kA at 690 VAC — a curve that tells you this breaker is sized for high-fault industrial distribution, not residential service. It's a line-protection design (not motor-protection), so the thermal-magnetic trip curve is set for cable and busbar protection in a main or subfeed panel. The 70 mm depth and 76.2 mm width mean it fits the standard SENTRON 3VA mounting footprint — same slot as other 3VA frame sizes, so a panel laid out for a 3VA1110 will accept this physically without re-drilling the backplate.
Breaking capacity — what the voltage steps mean for selectivity
At 240 V the 121 kA rating gives you headroom for a transformer-fed service with a high fault-current contribution. At 415 V it's still 75.6 kA, and at 440 V it drops to 52.5 kA — still enough for most European industrial networks. The 11.9 kA at 690 V is the limit; if your upstream transformer can push more than that at 690 V, this breaker needs a current-limiting upstream device or a larger-frame 3VA.
Current derating — the real ampacity in a warm panel
At 55 °C it derates to 49 A, at 60 °C to 48 A, at 65 °C to 46 A, and at 70 °C to 45 A.