What this MCCB carries — and what it means for the panel
The Siemens 3VA1050-4ED36-0CC0 is a 3-pole SENTRON molded case circuit breaker rated 50 A continuous at 40 °C, sized for line-protection duty in distribution panels. Breaking capacity hits 121 kA at 240 V AC and 75.6 kA at 415 V AC — that SCCR headroom means it clears high-fault bolted faults without cascading upstream, a real advantage when the transformer is close and the available fault current is stiff. At 440 V it still holds 52.5 kA, and at 500 V and 690 V it derates to 11.9 kA, so verify the system voltage against the curve before committing the BOM line. Current rating holds flat at 50 A from 40 °C through 50 °C, then steps down: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If the panel ambient runs above 50 °C, the continuous load must be trimmed accordingly — the derating curve is baked into the UL/CSA listing, not a suggestion. Width is 76.2 mm (3 in), depth 70 mm (2.76 in), height 130 mm (5.12 in) — a compact 3-pole footprint that drops into standard SENTRON mounting bases without re-drilling the gland plate. The integrated undervoltage release (UVR) and two HQ auxiliary switches are factory-fitted, so no field-add kit to track.
Integration notes
Mounts on a DIN rail or SENTRON mounting plate. The 3-pole design with UVR means the undervoltage coil must see rated voltage before the breaker will close — verify the control circuit supplies 24 V DC (or the UVR rating) and that the free-wheel diode polarity is correct if the coil is driven by a PLC output. Power loss at full load is 17.1 W max; factor that into enclosure thermal rise calculations. Insulation voltage rated 800 V, operating range -25 °C to 70 °C, storage -40 °C to 80 °C. The auxiliary switches are HQ type (high-quantity signal contacts) — rated for the same voltage class as the main poles, so they can drive panel indication or feed a PLC input directly.