The Siemens SENTRON 3VA1050-3ED36-0DC0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection, carrying a continuous current rating of 50 A at 40 °C and holding that same rating through 50 °C before derating to 49 A at 55 °C and 45 A at 70 °C. Breaking capacity runs 75.6 kA at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V, dropping to 7.5 kA at 500 V and 690 V. It includes an undervoltage release (UVR) and comes equipped with two auxiliary switches (HQ type). Rated insulation voltage is 800 V, and maximum power loss is 17.1 W.
What the ratings mean for fit
The 50 A continuous rating (at 40 °C) is the load current the breaker carries without tripping in a typical 40 °C panel ambient. If your panel runs hotter — say, 65 °C — the same breaker is good for 46 A. The 75.6 kA interrupting rating at 240 V is what the breaker can safely clear under a fault; at 415 V that drops to 52.5 kA, and at 690 V to 7.5 kA. For a 400 V distribution board, the 52.5 kA figure is the one that governs SCCR coordination upstream. The 3-pole design fits standard three-phase line protection, and the built-in undervoltage release (UVR) lets you trip the breaker on loss of control voltage — common for emergency-stop or safety circuits where a drop in the control supply should drop the load.
Deployment context
This MCCB mounts into a panel or enclosure on a standard DIN rail or direct-mount backplate. The 70 mm depth and 76.2 mm width fit within a typical 200 mm deep enclosure without crowding busbars. The two auxiliary switches (HQ) provide status feedback to a PLC or indicator lamp — one can signal the breaker position, the other can be wired into a safety chain. The undervoltage release (UVR) is factory-fitted, so no field assembly needed.