What it is and what it does
The Siemens 3VA1050-3ED42-0HA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection — it sits upstream in a distribution panel, guarding a feeder or a branch circuit against overloads and short circuits. Four poles, so it switches all three phases plus neutral in a 3-phase 4-wire system. The TM210 release is a thermal-magnetic type: the thermal element handles overloads (time-delayed), the magnetic element handles short-circuit faults (instantaneous). No communication function, no ground-fault monitoring — this is a straightforward, non-communicating breaker for standard power distribution.
Current rating and interrupting capacity — what they mean for fit
Rated 50 A continuous at 40 °C ambient, and it holds that rating all the way up to 50 °C — no derating needed in a warm panel. Above 50 °C it starts to step down: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, 45 A at 70 °C. That thermal curve is the one to check if your enclosure runs hot. Interrupting capacity is 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V. At 415 V — common for industrial distribution — the 52.5 kA rating means it can safely clear a fault current up to that level without rupturing. The 800 V rated insulation voltage confirms it's built for 690 V systems.
Auxiliary release and trip indication
This breaker includes a shunt trip (STL) auxiliary release — a voltage-triggered coil that lets you remotely trip the breaker by applying a control voltage. No undervoltage release, no trip indicator flag on the front. The shunt trip is useful for emergency-stop circuits or remote shutdown; wire it to a pushbutton or a safety relay. The basic switch inside is the 3VA10503ED420AA0 subassembly.
Physical footprint and panel fit
Dimensions: 130 mm high, 101.6 mm wide, 70 mm deep. That's a 4-inch wide body — standard for a 4-pole MCCB in the SENTRON 3VA1 frame. Mounts on a DIN rail or directly to a backplate via the breaker's own mounting feet. The 14.6 W maximum power loss at rated load is what the enclosure ventilation needs to handle; if you're packing several breakers side by side, add up the heat.