Siemens SENTRON 3VA1050-3ED36-0DA0 — 50 A MCCB with Undervoltage Release
It carries a TM210 thermal-magnetic release — the TM210 designation means the thermal element is fixed at 100% of the frame rating and the magnetic pickup is set at 10x In (500 A instantaneous), a common setting for general-purpose feeder protection.
Breaking capacity varies significantly with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at 500 V or 690 V. At 415 V — the common low-voltage distribution level in many industrial plants — the 52.5 kA rating provides substantial fault-current headroom for most panelboards.
Above that it derates linearly: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. In a sealed panel with poor airflow, factor in the actual enclosure ambient — at 60 °C you lose 2 A of headroom.