What this MCCB is and what it protects
The Siemens 3VA1050-2ED42-0HA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous current rating of 50 A at 40 °C, derating to 45 A at 70 °C, so the thermal curve is what governs the real ampacity in a warm enclosure — don't size it at 50 A if the ambient inside the panel runs above 55 °C. Four poles handle three-phase plus neutral switching, and the rated insulation voltage of 800 V gives headroom for 690 VAC systems. The breaking capacity hits 52.5 kA at 240 V and 32 kA at 415 V, which covers most industrial service-entrance and feeder applications where fault currents are high.
Shunt trip and overcurrent release
This variant includes a shunt trip (STL) auxiliary release (design designation in the order code), so it can be tripped remotely by a control signal — useful for emergency-stop circuits or interlocking with upstream protection. The overcurrent release is the TM210 thermal-magnetic type, which provides fixed thermal and magnetic trip settings for standard line protection without adjustable curves.
Physical fit and panel integration
The breaker measures 130 mm high, 101.6 mm wide, and 70 mm deep. The 4-pole width (101.6 mm) matches the standard 4-module MCCB footprint on DIN rail or panel-mount base plates. Verify the busbar or lug kit spacing against the existing panel layout — the shunt trip adds no extra width, but the wiring for the STL control signal needs a separate pair of terminals.
Power loss and thermal management
Maximum power loss is 14.6 W at rated current. In a densely packed panel, that heat needs to be considered for the enclosure's thermal budget — especially if the breaker is mounted next to other heat-generating devices. The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C.