What it is and what the ratings mean for fit
The Siemens 3VA1050-4ED36-0BC0 is a 3-pole SENTRON molded case circuit breaker (MCCB) rated for line protection, carrying a TM210 thermal-magnetic overcurrent release. The 50 A rated continuous current (Iu) holds across ambient temperatures from 40 °C through 50 °C, then derates to 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C — so if the panel ambient runs above 50 °C, the continuous load must be backed off accordingly, not left at 50 A. The interrupting ratings are the real selector: 121 kA at 240 V AC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. These numbers govern whether the breaker holds under a bolted fault at the available fault current on that bus. The 800 V rated insulation voltage (Ui) confirms the breaker is insulated for 690 V line-to-line service. The TM210 trip unit is a fixed thermal-magnetic design — no interchangeable electronic trip module, no ground-fault or communication function. The breaker ships with an undervoltage release (UVR) as the auxiliary release type, and the auxiliary contact version is 2 auxiliary switches HQ (high-qualified, typically form C). No voltage trigger or phase failure detection is built in. For a BOM freeze, the key fit check is whether the 50 A continuous rating and the interrupting capacity at your system voltage match the load and the available fault current on the distribution board.
Panel integration and deployment context
The breaker mounts on a DIN rail or panel-mount baseplate, typical for a distribution board or motor control center. Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — the width is a standard 3-pole MCCB footprint for the 3VA frame size. Front protection is IP40, meaning tools and fingers are kept out but the breaker is not sealed against washdown; it belongs in an enclosed panel, not a wet environment. Storage range is -40 °C to 80 °C; operating range is -25 °C to 70 °C.