What this MCCB delivers — and what it doesn't
The Siemens SENTRON 3VA1050-3ED36-0BC0 is a 3-pole molded case circuit breaker rated for line protection duty. Its rated continuous current Iu is 50 A, and it holds that rating from 40 °C up to 50 °C — only above 55 °C does it start to derate, dropping to 48 A at 55 °C and 45 A at 70 °C. That thermal profile means you can run it at full 50 A in a typical 40 °C panel without headroom concerns. The interrupting ratings are where this part differentiates itself: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and still 7.5 kA at 690 V. That 75.6 kA figure at 240 V is unusually high for a 50 A frame — it tells you this breaker is designed for high-fault-capacity downstream of a large transformer or in a low-voltage main distribution board where fault currents can exceed 65 kA.
Release and accessories — what's inside the frame
Overcurrent protection uses the TM210 release — a thermal-magnetic design with fixed thermal and magnetic trip settings tuned for line protection (cable and busbar protection, not motor starting). The breaker ships with an undervoltage release (UVR) integrated, part of the auxiliary release design. The auxiliary contact version fitted is 2 auxiliary switches HQ, and the integrated auxiliary trip is order code 3VA9608-0BB11. Rated insulation voltage Ui is 800 V, which covers 690 V systems with margin. The front face carries IP40 protection — fine for a closed panel, but not for washdown areas. No communication function, no phase failure detection, no ground fault monitoring. This is a straight line-protection breaker, not a multifunction power monitor.