What it is and what it does
The Siemens SENTRON 3VA1050-3ED36-0CH0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous rating of 50 A at 40 °C, derating to 45 A at 70 °C — the full thermal curve is on the nameplate, so factor in your enclosure ambient before sizing. Breaking capacity is 75.6 kA at 240 V AC, 52.5 kA at 415 V, and 32 kA at 440 V. At 500 V and 690 V it still holds 7.5 kA. That SCCR headroom covers most industrial service-entrance and feeder applications; verify your fault current at the point of installation.
Integrated auxiliaries and releases
This variant ships with an undervoltage release (UVR) fitted, plus 2 auxiliary switches and 1 trip alarm switch (HQ). The UVR drops the breaker on loss of control voltage — standard for emergency-stop chains or undervoltage protection schemes. The auxiliary contacts report breaker position back to the PLC or status panel without a separate contactor block. No communication module or ground-fault monitoring on this order code. If you need Modbus or RCM, step to the 3VA2 communication-capable frame. The 3VA1 platform here is a pure electromechanical MCCB with a trip-indicator flag.
Panel fit and environmental limits
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. The 3-pole footprint is standard for the 3VA1 frame — drops into the same cutout as the 3VA1 160 A frame, so a panel laid out for a larger rating accepts this 50 A unit without rework. Operating range is -25 °C to 70 °C; storage from -40 °C to 80 °C. Rated insulation voltage is 800 V, covering 480/600 V class systems with margin. Maximum power loss is 17.1 W — negligible for thermal budgeting in a standard enclosure, but tally it if the panel is densely packed.